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Li D, Yang Q, Luo J, Xu Y, Li J, Tao L. Bacterial toxins induce non-canonical migracytosis to aggravate acute inflammation. Cell Discov 2024; 10:112. [PMID: 39500876 PMCID: PMC11538519 DOI: 10.1038/s41421-024-00729-1] [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: 03/26/2024] [Accepted: 08/20/2024] [Indexed: 11/08/2024] Open
Abstract
Migracytosis is a recently described cellular process that generates and releases membrane-bound pomegranate-like organelles called migrasomes. Migracytosis normally occurs during cell migration, participating in various intercellular biological functions. Here, we report a new type of migracytosis induced by small GTPase-targeting toxins. Unlike classic migracytosis, toxin-induced migrasome formation does not rely on cell migration and thus can occur in both mobile and immobile cells. Such non-canonical migracytosis allows the cells to promptly respond to microbial stimuli such as bacterial toxins and effectors and release informative cellular contents in bulk. We demonstrated that C. difficile TcdB3 induces liver endothelial cells and Kupffer cells to produce migrasomes in vivo. Moreover, the migracytosis-defective Tspan9‒/‒ mice show less acute inflammation and lower lethality rate in the toxin challenge assay. Therefore, we propose that the non-canonical migracytosis acts as a new mechanism for mammalian species to sense and exacerbate early immune response upon microbial infections.
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Affiliation(s)
- Diyin Li
- College of Life Sciences, Zhejiang University, 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
- Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China
| | - Qi Yang
- College of Life Sciences, Zhejiang University, 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
- Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China
| | - Jianhua Luo
- 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
- Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China
- Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
| | - Yangyushuang Xu
- 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
- Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China
| | - Jingqing Li
- 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
- Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China
| | - Liang Tao
- College of Life Sciences, Zhejiang University, 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.
- Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China.
- Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China.
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2
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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.
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Affiliation(s)
- Michel R Popoff
- Unité des Toxines Bactériennes, Institut Pasteur, Université Paris Cité, CNRS UMR 2001 INSERM U1306, F-75015 Paris, France
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3
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Abstract
ADP-ribosylation (ADPr) is an ancient reversible modification of cellular macromolecules controlling major biological processes as diverse as DNA damage repair, transcriptional regulation, intracellular transport, immune and stress responses, cell survival and proliferation. Furthermore, enzymatic reactions of ADPr are central in the pathogenesis of many human diseases, including infectious conditions. By providing a review of ADPr signalling in bacterial systems, we highlight the relevance of this chemical modification in the pathogenesis of human diseases depending on host-pathogen interactions. The post-antibiotic era has raised the need to find alternative approaches to antibiotic administration, as major pathogens becoming resistant to antibiotics. An in-depth understanding of ADPr reactions provides the rationale for designing novel antimicrobial strategies for treatment of infectious diseases. In addition, the understanding of mechanisms of ADPr by bacterial virulence factors offers important hints to improve our knowledge on cellular processes regulated by eukaryotic homologous enzymes, which are often involved in the pathogenesis of human diseases.
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4
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Jamilloux Y, Magnotti F, Belot A, Henry T. The pyrin inflammasome: from sensing RhoA GTPases-inhibiting toxins to triggering autoinflammatory syndromes. Pathog Dis 2018; 76:4956042. [PMID: 29718184 DOI: 10.1093/femspd/fty020] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 03/02/2018] [Indexed: 02/07/2023] Open
Abstract
Numerous pathogens including Clostridium difficile and Yersinia pestis have evolved toxins or effectors targeting GTPases from the RhoA subfamily (RhoA/B/C) to inhibit or hijack the host cytoskeleton dynamics. The resulting impairment of RhoA GTPases activity is sensed by the host via an innate immune complex termed the pyrin inflammasome in which caspase-1 is activated. The cascade leading to activation of the pyrin inflammasome has been recently uncovered. In this review, following a brief presentation of RhoA GTPases-modulating toxins, we present the pyrin inflammasome and its regulatory mechanisms. Furthermore, we discuss how some pathogens have developed strategies to escape detection by the pyrin inflammasome. Finally, we present five monogenic autoinflammatory diseases associated with pyrin inflammasome deregulation. The molecular insights provided by the study of these diseases and the corresponding mutations on pyrin inflammasome regulation and activation are presented.
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Affiliation(s)
- Yvan Jamilloux
- Centre International de Recherche en Infectiologie (CIRI), Inserm U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, Ecole Normale Supérieure de Lyon, F-69007 Lyon, France.,Departement de Médecine Interne, Hopital de la Croix-Rousse, Université Claude Bernard Lyon 1, F-69004 Lyon, France
| | - Flora Magnotti
- Centre International de Recherche en Infectiologie (CIRI), Inserm U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, Ecole Normale Supérieure de Lyon, F-69007 Lyon, France
| | - Alexandre Belot
- Centre International de Recherche en Infectiologie (CIRI), Inserm U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, Ecole Normale Supérieure de Lyon, F-69007 Lyon, France.,Service de Néphrologie, Rhumatologie, Dermatologie pédiatrique, Hôpital Femme Mère Enfant, Hospices Civils de Lyon, F-69677 Lyon, France
| | - Thomas Henry
- Centre International de Recherche en Infectiologie (CIRI), Inserm U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, Ecole Normale Supérieure de Lyon, F-69007 Lyon, France
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5
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Stewart MP, Langer R, Jensen KF. Intracellular Delivery by Membrane Disruption: Mechanisms, Strategies, and Concepts. Chem Rev 2018; 118:7409-7531. [PMID: 30052023 PMCID: PMC6763210 DOI: 10.1021/acs.chemrev.7b00678] [Citation(s) in RCA: 459] [Impact Index Per Article: 65.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Intracellular delivery is a key step in biological research and has enabled decades of biomedical discoveries. It is also becoming increasingly important in industrial and medical applications ranging from biomanufacture to cell-based therapies. Here, we review techniques for membrane disruption-based intracellular delivery from 1911 until the present. These methods achieve rapid, direct, and universal delivery of almost any cargo molecule or material that can be dispersed in solution. We start by covering the motivations for intracellular delivery and the challenges associated with the different cargo types-small molecules, proteins/peptides, nucleic acids, synthetic nanomaterials, and large cargo. The review then presents a broad comparison of delivery strategies followed by an analysis of membrane disruption mechanisms and the biology of the cell response. We cover mechanical, electrical, thermal, optical, and chemical strategies of membrane disruption with a particular emphasis on their applications and challenges to implementation. Throughout, we highlight specific mechanisms of membrane disruption and suggest areas in need of further experimentation. We hope the concepts discussed in our review inspire scientists and engineers with further ideas to improve intracellular delivery.
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Affiliation(s)
- Martin P. Stewart
- Department of Chemical Engineering, Massachusetts Institute
of Technology, Cambridge, USA
- The Koch Institute for Integrative Cancer Research,
Massachusetts Institute of Technology, Cambridge, USA
| | - Robert Langer
- Department of Chemical Engineering, Massachusetts Institute
of Technology, Cambridge, USA
- The Koch Institute for Integrative Cancer Research,
Massachusetts Institute of Technology, Cambridge, USA
| | - Klavs F. Jensen
- Department of Chemical Engineering, Massachusetts Institute
of Technology, Cambridge, USA
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6
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Narumiya S, Thumkeo D. Rho signaling research: history, current status and future directions. FEBS Lett 2018; 592:1763-1776. [PMID: 29749605 PMCID: PMC6032899 DOI: 10.1002/1873-3468.13087] [Citation(s) in RCA: 119] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 04/30/2018] [Accepted: 05/02/2018] [Indexed: 12/24/2022]
Abstract
One of the main research areas in biology from the mid‐1980s through the 1990s was the elucidation of signaling pathways governing cell responses. These studies brought, among other molecules, the small GTPase Rho to the epicenter. Rho signaling research has since expanded to all areas of biology and medicine. Here, we describe how Rho emerged as a key molecule governing cell morphogenesis and movement, how it was linked to actin reorganization, and how the study of Rho signaling has expanded from cultured cells to whole biological systems. We then give an overview of the current research status of Rho signaling in development, brain, cardiovascular system, immunity and cancer, and discuss the future directions of Rho signaling research, with emphasis on one Rho effector, ROCK*.
*The Rho GTPase family. Rho family GTPases have now expanded to contain 20 members. Amino acid sequences of 20 Rho GTPases found in human were aligned and the phylogenetic tree was generated by ClustalW2 software (EMBL‐EBI) based on NJ algorithm. The subfamilies of the Rho GTPases are highlighted by the circle and labeled on the right side. Rho cited in this review refers to the original members of Rho subfamily, RhoA, RhoB and RhoC, that are C3 substrates, and, unless specified, not to other members of the Rho subfamily such as Rac, Cdc42, and Rnd. ![]()
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Affiliation(s)
- Shuh Narumiya
- Department of Drug Discovery Medicine, Medical Innovation Center, Kyoto University Graduate School of Medicine, Japan
| | - Dean Thumkeo
- Department of Drug Discovery Medicine, Medical Innovation Center, Kyoto University Graduate School of Medicine, Japan
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7
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"Bacterial Toxins" Section in the Journal Toxins: A Fantastic Multidisciplinary Interplay between Bacterial Pathogenicity Mechanisms, Physiological Processes, Genomic Evolution, and Subsequent Development of Identification Methods, Efficient Treatment, and Prevention of Toxigenic Bacteria. Toxins (Basel) 2018; 10:toxins10010044. [PMID: 29346271 PMCID: PMC5793131 DOI: 10.3390/toxins10010044] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 01/16/2018] [Accepted: 01/16/2018] [Indexed: 01/31/2023] Open
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8
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Lüscher B, Bütepage M, Eckei L, Krieg S, Verheugd P, Shilton BH. ADP-Ribosylation, a Multifaceted Posttranslational Modification Involved in the Control of Cell Physiology in Health and Disease. Chem Rev 2017; 118:1092-1136. [PMID: 29172462 DOI: 10.1021/acs.chemrev.7b00122] [Citation(s) in RCA: 177] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Posttranslational modifications (PTMs) regulate protein functions and interactions. ADP-ribosylation is a PTM, in which ADP-ribosyltransferases use nicotinamide adenine dinucleotide (NAD+) to modify target proteins with ADP-ribose. This modification can occur as mono- or poly-ADP-ribosylation. The latter involves the synthesis of long ADP-ribose chains that have specific properties due to the nature of the polymer. ADP-Ribosylation is reversed by hydrolases that cleave the glycosidic bonds either between ADP-ribose units or between the protein proximal ADP-ribose and a given amino acid side chain. Here we discuss the properties of the different enzymes associated with ADP-ribosylation and the consequences of this PTM on substrates. Furthermore, the different domains that interpret either mono- or poly-ADP-ribosylation and the implications for cellular processes are described.
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Affiliation(s)
- Bernhard Lüscher
- Institute of Biochemistry and Molecular Biology, Medical School, RWTH Aachen University , 52057 Aachen, Germany
| | - Mareike Bütepage
- Institute of Biochemistry and Molecular Biology, Medical School, RWTH Aachen University , 52057 Aachen, Germany
| | - Laura Eckei
- Institute of Biochemistry and Molecular Biology, Medical School, RWTH Aachen University , 52057 Aachen, Germany
| | - Sarah Krieg
- Institute of Biochemistry and Molecular Biology, Medical School, RWTH Aachen University , 52057 Aachen, Germany
| | - Patricia Verheugd
- Institute of Biochemistry and Molecular Biology, Medical School, RWTH Aachen University , 52057 Aachen, Germany
| | - Brian H Shilton
- Institute of Biochemistry and Molecular Biology, Medical School, RWTH Aachen University , 52057 Aachen, Germany.,Department of Biochemistry, Schulich School of Medicine & Dentistry, The University of Western Ontario , Medical Sciences Building Room 332, London, Ontario Canada N6A 5C1
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9
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Rho-inhibiting C2IN-C3 fusion toxin inhibits chemotactic recruitment of human monocytes ex vivo and in mice in vivo. Arch Toxicol 2017; 92:323-336. [PMID: 28924833 PMCID: PMC5773661 DOI: 10.1007/s00204-017-2058-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 08/31/2017] [Indexed: 10/24/2022]
Abstract
Bacterial protein toxins became valuable molecular tools for the targeted modulation of cell functions in experimental pharmacology and attractive therapeutics because of their potent and specific mode of action in human cells. C2IN-C3lim, a recombinant fusion toxin (~50 kDa) of the Rho-inhibiting C3lim from Clostridium (C.) limosum and a non-toxic portion of the C. botulinum C2 toxin (C2IN), is selectively internalized into the cytosol of monocytic cells where C3lim specifically ADP-ribosylates Rho A and -B, thereby inhibiting Rho-mediated signaling. Thus, we hypothesized that these unique features make C2IN-C3lim an attractive molecule for the targeted pharmacological down-regulation of Rho-mediated functions in monocytes. The analysis of the actin structure and the Rho ADP-ribosylation status implied that C2IN-C3lim entered the cytosol of primary human monocytes from healthy donors ex vivo within 1 h. Moreover, it inhibited the fMLP-induced chemotaxis of human monocytes in a Boyden chamber model ex vivo. Similarly, in a 3-dimensional ex vivo model of extravasation, single cell analysis revealed that C2IN-C3lim-treated cells were not able to move. In a clinically relevant mouse model of blunt chest trauma, the local application of C2IN-C3lim into the lungs after thorax trauma prevented the trauma-induced recruitment of monocytes into the lungs in vivo. Thus, C2IN-C3lim might be an attractive lead compound for novel pharmacological strategies to avoid the cellular damage response caused by monocytes in damaged tissue after trauma and during systemic inflammation. The results suggest that the pathophysiological role of clostridial C3 toxins might be a down-modulation of the innate immune system.
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10
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Takaki T, Montagner M, Serres MP, Le Berre M, Russell M, Collinson L, Szuhai K, Howell M, Boulton SJ, Sahai E, Petronczki M. Actomyosin drives cancer cell nuclear dysmorphia and threatens genome stability. Nat Commun 2017; 8:16013. [PMID: 28737169 PMCID: PMC5527285 DOI: 10.1038/ncomms16013] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2016] [Accepted: 05/24/2017] [Indexed: 12/16/2022] Open
Abstract
Altered nuclear shape is a defining feature of cancer cells. The mechanisms underlying nuclear dysmorphia in cancer remain poorly understood. Here we identify PPP1R12A and PPP1CB, two subunits of the myosin phosphatase complex that antagonizes actomyosin contractility, as proteins safeguarding nuclear integrity. Loss of PPP1R12A or PPP1CB causes nuclear fragmentation, nuclear envelope rupture, nuclear compartment breakdown and genome instability. Pharmacological or genetic inhibition of actomyosin contractility restores nuclear architecture and genome integrity in cells lacking PPP1R12A or PPP1CB. We detect actin filaments at nuclear envelope rupture sites and define the Rho-ROCK pathway as the driver of nuclear damage. Lamin A protects nuclei from the impact of actomyosin activity. Blocking contractility increases nuclear circularity in cultured cancer cells and suppresses deformations of xenograft nuclei in vivo. We conclude that actomyosin contractility is a major determinant of nuclear shape and that unrestrained contractility causes nuclear dysmorphia, nuclear envelope rupture and genome instability.
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Affiliation(s)
- Tohru Takaki
- Cell Division and Aneuploidy Laboratory, Cancer Research UK London Research Institute, Clare Hall Laboratories, South Mimms, Hertfordshire EN6 3LD, UK
- DSB Repair Metabolism Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Marco Montagner
- Tumour Cell Biology Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Murielle P. Serres
- Cell Division and Aneuploidy Laboratory, Cancer Research UK London Research Institute, Clare Hall Laboratories, South Mimms, Hertfordshire EN6 3LD, UK
- MRC Laboratory for Molecular Cell Biology, UCL, Gower Street, London WC1E 6BT, UK
| | - Maël Le Berre
- Institut Curie, PSL Research University, CNRS, UMR 144, F-75005 Paris, France
| | - Matt Russell
- Electron Microscopy Group, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Lucy Collinson
- Electron Microscopy Group, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Karoly Szuhai
- Department of Molecular Cell Biology, LUMC, Einthovenweg 20, 2333 ZC Leiden, The Netherlands
| | - Michael Howell
- High Throughput Screening Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Simon J. Boulton
- DSB Repair Metabolism Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Erik Sahai
- Tumour Cell Biology Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Mark Petronczki
- Cell Division and Aneuploidy Laboratory, Cancer Research UK London Research Institute, Clare Hall Laboratories, South Mimms, Hertfordshire EN6 3LD, UK
- Boehringer Ingelheim RCV GmbH & Co KG, Dr Boehringer Gasse 5-11, A-1121 Vienna, Austria
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11
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Abstract
The ADP-ribosyltransferase C3 exoenzyme from C. botulinum selectively inactivates Rho and is therefore often used as an inhibitor for investigations on Rho signaling. Previous studies of our group revealed that C3 inhibited cell proliferation in HT22 cells accompanied by increased transcriptional activities of Sp1 and c-Jun and reduced levels of cyclin D1, p21 and phosphorylated p38. By use of a p38α-deficient and a p38α-expressing control cell line, the impact of p38 on C3-mediated inhibition of cell proliferation and alterations on MAPK signaling was studied by growth kinetic experiments and Western blot analyses. The cell growth of p38α-expressing cells was impaired by C3, while the p38α-deficient cells did not exhibit any C3-induced effect. The activity of the MKK3/6-p38 MAPK signaling cascade as well as the phosphorylation of c-Jun and JNK was reduced by C3 exclusively in the presence of p38α. Moreover, the activity of upstream MAPKKK TAK1 was lowered in the p38α-expressing cells. These results indicated a resistance of p38α-deficient cells to C3-mediated inhibition of cell growth. This anti-proliferative effect was highly associated with the decreased activity of c-Jun and upstream p38 and JNK MAPK signaling as a consequence of the absence of p38α in these cells.
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12
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The GNA13-RhoA signaling axis suppresses expression of tumor protective Kallikreins. Cell Signal 2016; 28:1479-88. [PMID: 27424208 DOI: 10.1016/j.cellsig.2016.07.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 07/04/2016] [Accepted: 07/04/2016] [Indexed: 11/22/2022]
Abstract
Gα13 (encoded by GNA13 gene) is the alpha subunit of a heterotrimeric G-protein that mediates signaling through specific G-protein-coupled receptors (GPCRs). Increased GNA13 expression has been observed in metastatic breast cancer cells. Recently, we have shown that enhanced GNA13 signaling in MCF-10a cells, a benign breast cancer cell line increased its invasiveness. Previous studies have reported that Kallikrein-related peptidases (KLKs 1-15) are down-regulated in breast tumors and may have a tumor protective function. However, the mechanisms that lead to the down-regulation of KLK genes in breast cancer are yet to be elucidated. We found that enhanced GNA13 signaling represses KLK gene expression in breast cancer, and undertook examination of the mechanisms involved. A microarray analysis revealed down-regulation of several members of the Kallikrein-related peptidases (KLK) gene family, namely KLK5, KLK6, KLK7, KLK8 and KLK10, in MCF-10a lines with enhanced GNA13 protein expression. Using real-time PCR and promoter analysis, we identified that the mRNA expression and promoter activities of these KLKs are suppressed upon enforced expression of GNA13 in MCF-10a cells. Using Rhotekin pull-down assays, we identified that GNA13 suppressed Rho-A activation and protein levels in MCF-10a cells. Blocking Rho-A activation using C3-toxin or by inhibiting its down-stream effector, Rho-associated kinase (ROCK), reduced the above-mentioned KLK mRNAs in MCF-10A cells. Importantly, in a metastatic breast cancer cell line MDA-MB-157, knock down of GNA13 alone was sufficient to induce the expression KLK mRNAs. Taken together, our findings suggested that enhanced GNA13 signaling down-regulates KLK gene transcription. The ability of enhanced GNA13 signaling to suppress KLK gene expression appears at least in part due to the ability of enhanced GNA13 signaling to negatively impact Rho/ROCK-signaling.
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13
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Tsuge H, Yoshida T, Tsurumura T. Conformational plasticity is crucial for C3-RhoA complex formation by ARTT-loop. Pathog Dis 2015; 73:ftv094. [PMID: 26474844 DOI: 10.1093/femspd/ftv094] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/14/2015] [Indexed: 01/22/2023] Open
Abstract
ADP-ribosylation is an important post-translational protein modification catalyzed by bacterial toxins and eukaryotic endogenous ADP-ribosyltransferases. Bacterial binary toxins and C3-like toxins recognize and ADP-ribosylate actin Arg177 and RhoA Asn41, respectively. Structural and mutational studies have identified an ADP-ribosylating turn-turn loop (ARTT-loop) that has been implicated in substrate specificity and recognition, although it has not been verified. Recently, we determined the crystal structure of the C3 exoenzyme-RhoA complex. The complex structure shows how C3 recognizes Rho GTPase and provides the first structural evidence for RhoA recognition by the ARTT-loop. The complex formation mediated by the ARTT-loop is through the intrinsic plasticity of C3 and RhoA. C3 changes the conformations of both the phosphate nicotinamide-loop and the ARTT-loop by NAD(+) and RhoA binding, respectively. In contrast, RhoA changes the conformations of switch I and II regions upon C3 binding with a particular conformation, irrespective of the bound nucleotide (GTP or GDP).
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Affiliation(s)
- Hideaki Tsuge
- Department of Bioresource and Environmental Sciences, Faculty of Life Sciences and Structural Biology Research Center, Kyoto Sangyo University, Kamigamo-Motoyama, Kyoto 603-8555, Japan
| | - Toru Yoshida
- Department of Bioresource and Environmental Sciences, Faculty of Life Sciences and Structural Biology Research Center, Kyoto Sangyo University, Kamigamo-Motoyama, Kyoto 603-8555, Japan
| | - Toshiharu Tsurumura
- Department of Bioresource and Environmental Sciences, Faculty of Life Sciences and Structural Biology Research Center, Kyoto Sangyo University, Kamigamo-Motoyama, Kyoto 603-8555, Japan
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14
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Rohrbeck A, Stahl F, Höltje M, Hettwer T, Lindner P, Hagemann S, Pich A, Haastert-Talini K. C3-induced release of neurotrophic factors from Schwann cells - potential mechanism behind its regeneration promoting activity. Neurochem Int 2015; 90:232-45. [PMID: 26417907 DOI: 10.1016/j.neuint.2015.09.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 09/11/2015] [Accepted: 09/23/2015] [Indexed: 01/10/2023]
Abstract
Previous studies revealed a peripheral nerve regeneration (PNR)(1) promoting activity of Clostridium botulinum C3(2) exoenzyme or a 26(mer) C-terminal peptide fragment covering amino acids 156-181 (C3(156-181)),(3) when delivered as one-time injection at the lesion site. The current study was performed to 1) investigate if prolonged availability of C3 and C3(156-181) at the lesion site can further enhance PNR in vivo and to 2) elucidate effects of C3 and C3(156-181) on Schwann cells (SCs)(4)in vitro. For in vivo studies, 10 mm adult rat sciatic nerve gaps were reconstructed with the epineurial pouch technique or autologous nerve grafts. Epineurial pouches were filled with a hydrogel containing i) vehicle, ii) 40 μM C3 or iii) 40 μM C3(156-181). Sensory and motor functional recovery was monitored over 12 weeks and the outcome of PNR further analyzed by nerve morphometry. In vitro, we compared gene expression profiles (microarray analysis) and neurotrophic factor expression (western blot analysis) of untreated rat neonatal SCs with those treated with C3 or C3(156-181) for 72 h. Effects on neurotrophic factor expression levels were proven in adult human SCs. Unexpectedly, prolonged delivery of C3 and C3(156-181) at the lesion site did not increase the outcome of PNR. Regarding the potential mechanism underlying their previously detected PNR promoting action, however, 6 genes were found to be commonly altered in SCs upon treatment with C3 or C3(156-181). We demonstrate significant down-regulation of genes involved in glutamate uptake (Eaac1,(5)Grin2a(6)) and changes in neurotrophic factor expression (increase of FGF-2(7) and decrease of NGF(8)). Our microarray-based expression profiling revealed novel C3-regulated genes in SCs possibly involved in the axonotrophic (regeneration promoting) effects of C3 and C3(156-181). Detection of altered neurotrophic factor expression by C3 or C3(156-181) treated primary neonatal rat SCs and primary adult human SCs supports this hypothesis.
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Affiliation(s)
- Astrid Rohrbeck
- Institute of Toxicology, Hannover Medical School, Carl-Neuberg-Str. 1, D-30625 Hannover, Germany.
| | - Frank Stahl
- Institute for Technical Chemistry, Leibniz University of Hannover, Callinstr. 5, D-30167 Hannover, Germany
| | - Markus Höltje
- Institute for Integrative Neuroanatomy, Charité-Universitätsmedizin Berlin, Charitéplatz 1, D-10117 Berlin, Germany
| | - Timo Hettwer
- Institute of Neuroanatomy, Hannover Medical School and Carl-Neuberg-Str. 1, D-30625 Hannover, Germany
| | - Patrick Lindner
- Institute for Technical Chemistry, Leibniz University of Hannover, Callinstr. 5, D-30167 Hannover, Germany
| | - Sandra Hagemann
- Institute of Toxicology, Hannover Medical School, Carl-Neuberg-Str. 1, D-30625 Hannover, Germany
| | - Andreas Pich
- Institute of Toxicology, Hannover Medical School, Carl-Neuberg-Str. 1, D-30625 Hannover, Germany
| | - Kirsten Haastert-Talini
- Institute of Neuroanatomy, Hannover Medical School and Carl-Neuberg-Str. 1, D-30625 Hannover, Germany; Center for Systems Neuroscience (ZSN), Carl-Neuberg-Str. 1, D-30625 Hannover, Germany.
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15
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Affiliation(s)
| | - Nicolas Bourmeyster
- Laboratoire Signalisation et Transports Ioniques Membranaires (STIM); Université de Poitiers Poitiers Cédex, France
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16
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Yang J, Xu H, Shao F. The immunological function of familial Mediterranean fever disease protein Pyrin. SCIENCE CHINA-LIFE SCIENCES 2014; 57:1156-61. [DOI: 10.1007/s11427-014-4758-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 09/11/2014] [Indexed: 02/04/2023]
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17
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Koch JC, Tönges L, Michel U, Bähr M, Lingor P. Viral vector-mediated downregulation of RhoA increases survival and axonal regeneration of retinal ganglion cells. Front Cell Neurosci 2014; 8:273. [PMID: 25249936 PMCID: PMC4155783 DOI: 10.3389/fncel.2014.00273] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 08/20/2014] [Indexed: 12/26/2022] Open
Abstract
The Rho/ROCK pathway is a promising therapeutic target in neurodegenerative and neurotraumatic diseases. Pharmacological inhibition of various pathway members has been shown to promote neuronal regeneration and survival. However, because pharmacological inhibitors are inherently limited in their specificity, shRNA-mediated approaches can add more information on the function of each single kinase involved. Thus, we generated adeno-associated viral vectors (AAV) to specifically downregulate Ras homologous member A (RhoA) via shRNA. We found that specific knockdown of RhoA promoted neurite outgrowth of retinal ganglion cells (RGC) grown on the inhibitory substrate chondroitin sulfate proteoglycan (CSPG) as well as neurite regeneration of primary midbrain neurons (PMN) after scratch lesion. In the rat optic nerve crush (ONC) model in vivo, downregulation of RhoA significantly enhanced axonal regeneration compared to control. Moreover, survival of RGC transduced with AAV expressing RhoA-shRNA was substantially increased at 2 weeks after optic nerve axotomy. Compared to previous data using pharmacological inhibitors to target RhoA, its upstream regulator Nogo or its main downstream target ROCK, the specific effects of RhoA downregulation shown here were most pronounced in regard to promoting RGC survival but neurite outgrowth and axonal regeneration were also increased significantly. Taken together, we show here that specific knockdown of RhoA substantially increases neuronal survival after optic nerve axotomy and modestly increases neurite outgrowth in vitro and axonal regeneration after optic nerve crush.
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Affiliation(s)
- Jan Christoph Koch
- Department of Neurology, University Medicine Göttingen Göttingen, Germany
| | - Lars Tönges
- Department of Neurology, University Medicine Göttingen Göttingen, Germany
| | - Uwe Michel
- Department of Neurology, University Medicine Göttingen Göttingen, Germany
| | - Mathias Bähr
- Department of Neurology, University Medicine Göttingen Göttingen, Germany ; Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB) Göttingen, Germany
| | - Paul Lingor
- Department of Neurology, University Medicine Göttingen Göttingen, Germany ; Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB) Göttingen, Germany
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18
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Simon NC, Aktories K, Barbieri JT. Novel bacterial ADP-ribosylating toxins: structure and function. Nat Rev Microbiol 2014; 12:599-611. [PMID: 25023120 PMCID: PMC5846498 DOI: 10.1038/nrmicro3310] [Citation(s) in RCA: 159] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Bacterial ADP-ribosyltransferase toxins (bARTTs) transfer ADP-ribose to eukaryotic proteins to promote bacterial pathogenesis. In this Review, we use prototype bARTTs, such as diphtheria toxin and pertussis toxin, as references for the characterization of several new bARTTs from human, insect and plant pathogens, which were recently identified by bioinformatic analyses. Several of these toxins, including cholix toxin (ChxA) from Vibrio cholerae, SpyA from Streptococcus pyogenes, HopU1 from Pseudomonas syringae and the Tcc toxins from Photorhabdus luminescens, ADP-ribosylate novel substrates and have unique organizations, which distinguish them from the reference toxins. The characterization of these toxins increases our appreciation of the range of structural and functional properties that are possessed by bARTTs and their roles in bacterial pathogenesis.
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Affiliation(s)
- Nathan C. Simon
- Medical College of Wisconsin, Microbiology and Molecular Genetics, Milwaukee, WI, USA
| | - Klaus Aktories
- Institute of Experimental and Clinical Pharmacology and Toxicology; Albert-Ludwigs-University Freiburg; Freiburg, Germany
| | - Joseph T. Barbieri
- Medical College of Wisconsin, Microbiology and Molecular Genetics, Milwaukee, WI, USA
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19
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Martin SG, Arkowitz RA. Cell polarization in budding and fission yeasts. FEMS Microbiol Rev 2014; 38:228-53. [DOI: 10.1111/1574-6976.12055] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Revised: 11/13/2013] [Accepted: 12/03/2013] [Indexed: 11/30/2022] Open
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20
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Jordan SN, Canman JC. Rho GTPases in animal cell cytokinesis: an occupation by the one percent. Cytoskeleton (Hoboken) 2012; 69:919-30. [PMID: 23047851 DOI: 10.1002/cm.21071] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Revised: 09/04/2012] [Accepted: 09/06/2012] [Indexed: 12/17/2022]
Abstract
Rho GTPases are molecular switches that elicit distinct effects on the actomyosin cytoskeleton to accurately promote cytokinesis. Although they represent less than 1% of the human genome, Rho GTPases exert disproportionate control over cell division. Crucial to this master regulatory role is their localized occupation of specific domains of the cell to ensure the assembly of a contractile ring at the proper time and place. RhoA occupies the division plane and is the central positive Rho family regulator of cytokinesis. Rac1 is a negative regulator of cytokinesis and is inactivated within the division plane while active Rac1 occupies the cell poles. Cdc42 regulation during cytokinesis is less studied, but thus far a clear role has only been shown during polar body emission. Here we review what is known about the function of Rho family GTPases during cell division, as well as their upstream regulators and known downstream cytokinetic effectors.
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Affiliation(s)
- Shawn N Jordan
- Department of Pathology and Cell Biology, Columbia University, New York, NY 10032, USA
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21
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Aguilera MO, Berón W, Colombo MI. The actin cytoskeleton participates in the early events of autophagosome formation upon starvation induced autophagy. Autophagy 2012; 8:1590-603. [PMID: 22863730 DOI: 10.4161/auto.21459] [Citation(s) in RCA: 121] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Autophagy is a process by which cytoplasmic material is sequestered in a double-membrane vesicle destined for degradation. Nutrient deprivation stimulates the pathway and the number of autophagosomes in the cell increases in response to such stimulus. In the current report we have demonstrated that actin is necessary for starvation-mediated autophagy. When the actin cytoskeleton is depolymerized, the increase in autophagic vacuoles in response to the starvation stimulus was abolished without affecting maturation of remaining autophagosomes. In addition, actin filaments colocalized with ATG14, BECN1/Beclin1 and PtdIns3P-rich structures, and some of them have a typical omegasome shape stained with the double FYVE domain or ZFYVE1/DFCP1. In contrast, no major colocalization between actin and ULK1, ULK2, ATG5 or MAP1LC3/LC3 was observed. Taken together, our data indicate that actin has a role at very early stages of autophagosome formation linked to the PtdIns3P generation step. In addition, we have found that two members of the Rho family of proteins, RHOA and RAC1 have a regulatory function on starvation-mediated autophagy, but with opposite roles. Indeed, RHOA has an activatory role whereas Rac has an inhibitory one. We have also found that inhibition of the RHOA effector ROCK impaired the starvation-mediated autophagic response. We propose that actin participates in the initial membrane remodeling stage when cells require an enhanced rate of autophagosome formation, and this actin function would be tightly regulated by different members of the Rho family.
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Affiliation(s)
- Milton Osmar Aguilera
- Laboratorio de Biología Celular y Molecular, Instituto de Histología y Embriología, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo-CONICET, Mendoza, Argentina
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22
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Zhou Z, Kim J, Insolera R, Peng X, Fink DJ, Mata M. Rho GTPase regulation of α-synuclein and VMAT2: implications for pathogenesis of Parkinson's disease. Mol Cell Neurosci 2011; 48:29-37. [PMID: 21699982 PMCID: PMC3163163 DOI: 10.1016/j.mcn.2011.06.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Revised: 05/06/2011] [Accepted: 06/01/2011] [Indexed: 12/15/2022] Open
Abstract
Accumulation of α-synuclein (Asyn) in neuronal perikarya and dystrophic neurites is characteristic of idiopathic and familial Parkinson's disease. In this study, we investigated the relationship between α-synuclein expression and neurite outgrowth-maturation using MN9D dopaminergic cells and demonstrated key features of Asyn regulation in hippocampal neurons. Neurite elongation elicited by inhibition of Rho GTPase activity with C3 transferase or by db-cAMP treatment was associated with marked reduction of α-synuclein mRNA and protein expression. Rho inhibition resulted in reduction of transcription factor SRF in the nuclear fraction and retention of MKL-1 - the SRF co-transactivator of SRE - in cytosol, indicating that these effects of Rho inhibition may be mediated though reduction of SRF-SRE transcription. Inhibition of Rho GTPase activity led to decreased nuclear localization of GATA2, a key regulator of α-synuclein promoter activity. Rho inhibition-induced neurite extension was associated with increased VMAT2 and SNARE proteins synaptophysin and synapsin I. These results indicate that in the MN9D dopaminergic cell line, α-synuclein transcription and levels of synaptic vesicle associated proteins are inversely correlated with neurite growth. We confirm that in mature hippocampal neurons inhibition of RhoA and knock down of SRF by siRNA also lead to decrease GATA2 and Asyn. The results suggest that RhoA signaling may be potential therapeutic target for the treatment of synucleinopathies.
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Affiliation(s)
- Zhigang Zhou
- Department of Neurology, University of Michigan and VA Ann Arbor Healthcare System, 5031 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI, 48109
| | - Jeeyong Kim
- Department of Neurology, University of Michigan and VA Ann Arbor Healthcare System, 5031 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI, 48109
| | - Ryan Insolera
- Department of Neurology, University of Michigan and VA Ann Arbor Healthcare System, 5031 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI, 48109
| | - Xiangmin Peng
- Department of Neurology, University of Michigan and VA Ann Arbor Healthcare System, 5031 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI, 48109
| | - David J. Fink
- Department of Neurology, University of Michigan and VA Ann Arbor Healthcare System, 5031 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI, 48109
| | - Marina Mata
- Department of Neurology, University of Michigan and VA Ann Arbor Healthcare System, 5031 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI, 48109
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23
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Abstract
Many bacterial pathogens produce protein toxins to outmanoeuvre the immune system of the host. Some of these proteins target regulatory GTPases such as those belonging to the RHO family, which control the actin cytoskeleton of the host cell. In this Review, I discuss a diversity of mechanisms that are used by bacterial effectors and toxins to modulate the activity of host GTPases, with a focus on covalent modifications such as ADP-ribosylation, glucosylation, adenylylation, proteolysis, deamidation and transglutamination.
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Affiliation(s)
- Klaus Aktories
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Albert-Ludwigs-Universität Freiburg, Albertstr. 25, 79104 Freiburg, Germany.
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24
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Liao G, Ma X, Liu G. An RNA-zipcode-independent mechanism that localizes Dia1 mRNA to the perinuclear ER through interactions between Dia1 nascent peptide and Rho-GTP. J Cell Sci 2011; 124:589-99. [PMID: 21266463 DOI: 10.1242/jcs.072421] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Signal-peptide-mediated ER localization of mRNAs encoding for membrane and secreted proteins, and RNA-zipcode-mediated intracellular targeting of mRNAs encoding for cytosolic proteins are two well-known mechanisms for mRNA localization. Here, we report a previously unidentified mechanism by which mRNA encoding for Dia1, a cytosolic protein without the signal peptide, is localized to the perinuclear ER in an RNA-zipcode-independent manner in fibroblasts. Dia1 mRNA localization is also independent of the actin and microtubule cytoskeleton but requires translation and the association of Dia1 nascent peptide with the ribosome-mRNA complex. Sequence mapping suggests that interactions of the GTPase binding domain of Dia1 peptide with active Rho are important for Dia1 mRNA localization. This mechanism can override the β-actin RNA zipcode and redirect β-actin mRNA to the perinuclear region, providing a new way to manipulate intracellular mRNA localization.
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Affiliation(s)
- Guoning Liao
- Center for Cell Biology and Cancer Research, Albany Medical College, Albany, NY 12208, USA
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25
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Just I, Rohrbeck A, Huelsenbeck SC, Hoeltje M. Therapeutic effects of Clostridium botulinum C3 exoenzyme. Naunyn Schmiedebergs Arch Pharmacol 2010; 383:247-52. [PMID: 21193903 DOI: 10.1007/s00210-010-0589-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2010] [Accepted: 12/12/2010] [Indexed: 12/17/2022]
Abstract
C3 exoenzyme from Clostridium botulinum, specifically ADP-ribosylates small GTP-binding proteins RhoA, B, and C. ADP-ribosylation causes functional inactivation of Rho proteins resulting in cessation of the complete downstream signaling. Rho proteins are general regulators of a lot of essential cellular functions, among others, the neuronal growth cone. Rho activation, triggered by neuronal injury, inhibits neuronal repair mechanisms. To prevent the detrimental effect of active Rho in the recovery of injured neuronal systems, C3 has become a promising drug to inactivate RhoA in neurons. During the advancement of C3 to a drug candidate, it was found that ADP-ribosyltransferase activity of C3, in fact, is not essential for axonal and dendritic growth and branching. Rather, a peptide fragment of C3 covering the surface exposed ARTT loop from C3 (C3(154-182) peptide) is sufficient to induce growth and branching of neurons comparable to the effect of full-length C3. Whereas full-length C3 also acts on astrocytes and microglia to induce-at least in an in vitro model-inflammation and glial scar formation, C3(154-182) peptide is inert and seems only to act on neurons. In addition to its axono- and dendritotrophic effects on cultured primary hippocampal neurons, C3(154-182) peptide enhanced functional recovery and regeneration in a mouse model of spinal cord injury. Thus, in a proof-of-principle experiment, C3 peptide was shown to be efficacious in post-traumatic neuro-regeneration.
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Affiliation(s)
- Ingo Just
- Institut für Toxikologie, Medizinische Hochschule Hannover, 30625 Hannover, Germany.
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26
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Lang AE, Schmidt G, Sheets JJ, Aktories K. Targeting of the actin cytoskeleton by insecticidal toxins from Photorhabdus luminescens. Naunyn Schmiedebergs Arch Pharmacol 2010; 383:227-35. [PMID: 21072628 DOI: 10.1007/s00210-010-0579-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2010] [Accepted: 10/27/2010] [Indexed: 10/18/2022]
Abstract
Photorhabdus luminescens produces several types of protein toxins, which are essential for participation in a trilateral symbiosis with nematodes and insects. The nematodes, carrying the bacteria, invade insect larvae and release the bacteria, which kill the insects with their toxins. Recently, the molecular mechanisms of the toxin complexes PTC3 and PTC5 have been elucidated. The biologically active components of the toxin complexes are ADP-ribosyltransferases, which modify actin and Rho GTPases, respectively. The actions of the toxins are described and compared with other bacterial protein toxins acting on the cytoskeleton.
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Affiliation(s)
- Alexander E Lang
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Albert-Ludwigs-Universität Freiburg, Albertstrasse 25, 79104 Freiburg, Germany
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27
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Affiliation(s)
- C.B. SHUSTER
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - I.M. HERMAN
- Department of Physiology, Tufts University School of Medicine, Boston, MA, USA
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28
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Popoff MR, Geny B. Multifaceted role of Rho, Rac, Cdc42 and Ras in intercellular junctions, lessons from toxins. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2009; 1788:797-812. [PMID: 19366594 DOI: 10.1016/j.bbamem.2009.01.011] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2008] [Revised: 01/20/2009] [Accepted: 01/22/2009] [Indexed: 12/20/2022]
Abstract
Tight junctions (TJs) and adherens junctions (AJs) are dynamic structures linked to the actin cytoskeleton, which control the paracellular permeability of epithelial and endothelial barriers. TJs and AJs are strictly regulated in a spatio-temporal manner by a complex signaling network, including Rho/Ras-GTPases, which have a pivotal role. Rho preferentially regulates TJs by controlling the contraction of apical acto-myosin filaments, whereas Rac/Cdc42 mainly coordinate the assembly-disassembly of AJ components. However, a subtle balance of Rho/Ras-GTPase activity and interplay between these molecules is required to maintain an optimal organization and function of TJs and AJs. Conversely, integrity of intercellular junctions generates signals through Rho-GTPases, which are involved in the regulation of multiple cellular processes. Rho/Ras-GTPases and the control of intercellular junctions are the target of various bacterial toxins responsible for severe diseases in man and animals, and are part of their mechanism of action. This review focuses on the regulation of TJs and AJs by Rho/Ras-GTPases through molecular approaches and bacterial toxins.
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Affiliation(s)
- Michel R Popoff
- Institut Pasteur, Unité des Bactéries anaérobies et Toxines, 75724 Paris cedex151, France.
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29
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Dubash AD, Menold MM, Samson T, Boulter E, García-Mata R, Doughman R, Burridge K. Chapter 1 Focal Adhesions: New Angles on an Old Structure. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2009; 277:1-65. [DOI: 10.1016/s1937-6448(09)77001-7] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
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30
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Ménétrey J, Flatau G, Boquet P, Ménez A, Stura EA. Structural basis for the NAD-hydrolysis mechanism and the ARTT-loop plasticity of C3 exoenzymes. Protein Sci 2008; 17:878-86. [PMID: 18369192 PMCID: PMC2327275 DOI: 10.1110/ps.073398508] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2007] [Revised: 02/13/2008] [Accepted: 02/13/2008] [Indexed: 12/18/2022]
Abstract
C3-like exoenzymes are ADP-ribosyltransferases that specifically modify some Rho GTPase proteins, leading to their sequestration in the cytoplasm, and thus inhibiting their regulatory activity on the actin cytoskeleton. This modification process goes through three sequential steps involving NAD-hydrolysis, Rho recognition, and binding, leading to Rho ADP-ribosylation. Independently, three distinct residues within the ARTT loop of the C3 exoenzymes are critical for each of these steps. Supporting the critical role of the ARTT loop, we have shown previously that it adopts a distinct conformation upon NAD binding. Here, we present seven wild-type and ARTT loop-mutant structures of C3 exoenzyme of Clostridium botulinum free and bound to its true substrate, NAD, and to its NAD-hydrolysis product, nicotinamide. Altogether, these structures expand our understanding of the conformational diversity of the C3 exoenzyme, mainly within the ARTT loop.
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Affiliation(s)
- Julie Ménétrey
- Institut Curie, Centre de Recherche, Paris F-75248, France.
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31
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Zhang Z, Schittenhelm J, Meyermann R, Schluesener HJ. Lesional accumulation of RhoA+cells in brains of experimental autoimmune encephalomyelitis and multiple sclerosis. Neuropathol Appl Neurobiol 2008; 34:231-40. [DOI: 10.1111/j.1365-2990.2007.00892.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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32
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Zhang Z, Fauser U, Schluesener HJ. Dexamethasone suppresses infiltration of RhoA+ cells into early lesions of rat traumatic brain injury. Acta Neuropathol 2008; 115:335-43. [PMID: 17929039 DOI: 10.1007/s00401-007-0301-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2007] [Revised: 09/02/2007] [Accepted: 09/18/2007] [Indexed: 01/19/2023]
Abstract
Inflammatory cell infiltration is a major part of secondary tissue damage in traumatic brain injury (TBI). RhoA is an important member of Rho GTPases and is involved in leukocyte migration. Inhibition of RhoA and its downstream target, Rho-associated coiled kinase (ROCK), has been proven to promote axon regeneration and function recovery following injury in the central nervous system (CNS). Previously, we showed that dexamethasone, an immunosuppressive corticosteroid, attenuated early expression of three molecules associated with microglia/macrophages activation following TBI in rats. Here, the effects of dexamethasone on the early expression of RhoA have been investigated in brains of TBI rats by immunohistochemistry. In brains of rats treated with TBI alone, significant RhoA+ cell accumulation was observed at 18 h post-injury and continuously increased during our observed time period. The accumulated RhoA+ cells were distributed to the areas of pannecrosis and selective neuronal loss. Most accumulated RhoA+ cells were identified as active microglia/macrophages by double-labelling. Dexamethasone (1 mg/kg body weight) was intraperitoneally injected on day 0 and 2 immediately following brain injury. Numbers of RhoA+ cells were significantly reduced on day 1 and 2 following administration of dexamethasone but returned to vehicle control level on day 4. However, dexamethasone treatment did not change the proportion of RhoA+ cells. These observations suggest that dexamethasone has only a transient effect on early leukocyte recruitment.
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Affiliation(s)
- Zhiren Zhang
- Institute of Brain Research, University of Tuebingen, Calwer Str. 3, 72076 Tuebingen, Germany.
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33
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Tao Y, Chen YC, Li YY, Yang SQ, Xu WR. Localization and translocation of RhoA protein in the human gastric cancer cell line SGC-7901. World J Gastroenterol 2008; 14:1175-81. [PMID: 18300342 PMCID: PMC2690664 DOI: 10.3748/wjg.14.1175] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To elucidate the localization of RhoA in gastric SGC-7901 cancer cells and its translocation by lysophosphatidic acid (LPA) and/or 8-chlorophenylthio-cAMP (CPT-cAMP).
METHODS: Immunofluorescence microscopy was used to determine the localization of RhoA. Western blotting was used to detect both endogenous and exogenous RhoA in different cellular compartments (membrane, cytosol, nucleus) and the translocation of RhoA following treatment with LPA, CPT-cAMP, or CPT-cAMP + LPA.
RESULTS: Immunofluorescence staining revealed endogenous RhoA to be localized in the membrane, the cytosol, and the nucleus, and its precise localization within the nucleus to be the nucleolus. Western blotting identified both endogenous and exogenous RhoA within different cellular compartments (membrane, cytosol, nucleus, nucleolus). After stimulation with LPA, the amount of RhoA within membrane and nuclear extracts increased, while it decreased in the cytosol fractions. After treatment with CPT-cAMP the amount of RhoA within the membrane and the nuclear extracts decreased, while it increased within the cytosol fraction. Treatment with a combination of both substances led to a decrease in RhoA in the membrane and the nucleus but to an increase in the cytosol.
CONCLUSION: In SGC-7901 cells RhoA was found to be localized within the membrane, the cytosol, and the nucleus. Within the nucleus its precise localization could be demonstrated to be the nucleolus. Stimulation with LPA caused a translocation of RhoA from the cytosol towards the membrane and the nucleus; treatment with CPT-cAMP caused the opposite effect. Furthermore, pre-treatment with CPT-cAMP was found to block the effect of LPA.
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Pan J, You Y, Huang T, Brody SL. RhoA-mediated apical actin enrichment is required for ciliogenesis and promoted by Foxj1. J Cell Sci 2007; 120:1868-76. [PMID: 17488776 DOI: 10.1242/jcs.005306] [Citation(s) in RCA: 169] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Programs that direct cellular differentiation are dependent on the strict temporal expression of regulatory factors that can be provided by Rho GTPases. Ciliogenesis is a complex sequence of events involving the generation and docking of basal bodies at the apical membrane, followed by ciliary axoneme generation. Although a cilia proteome has been assembled, programs that direct ciliated cell differentiation are not well established, particularly in mammalian systems. Using mouse primary culture airway epithelial cells, we identified a critical stage of ciliogenesis requiring the temporal establishment of an apical web-like structure of actin for basal body docking and subsequent axoneme growth. Apical web formation and basal body docking were prevented by interruption of actin remodeling and were dependent on RhoA activation. Additional evidence for this program was provided by analysis of Foxj1-null mice that failed to dock basal bodies and lacked apical actin. Foxj1 expression coincided with actin web formation, activated RhoA and RhoB, and persisted despite RhoA inhibition, suggesting that Foxj1 promoted RhoA during ciliogenesis. Apical ezrin localization was also dependent on Foxj1, actin remodeling, and RhoA, but was not critical for ciliogenesis. Thus, temporal Foxj1 and RhoA activity are essential regulatory events for cytoskeletal remodeling during mammalian ciliogenesis.
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Affiliation(s)
- Jiehong Pan
- Pulmonary and Critical Care Medicine, Department of Internal Medicine, Washington University School of Medicine, St Louis, MO 63110, USA
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Zhang Z, Fauser U, Schluesener HJ. Expression of RhoA by inflammatory macrophages and T cells in rat experimental autoimmune neuritis. J Cell Mol Med 2007; 11:111-9. [PMID: 17367505 PMCID: PMC4401224 DOI: 10.1111/j.1582-4934.2007.00004.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
RhoA is one of the best-studied members of Rho GTPases. Experimental autoimmune neuritis (EAN), which is characterized by infiltration of T cells and macrophages into the peripheral nervous system, is an autoantigen-specific T-cell-mediated animal model of human Guillain-Barré Syndrome. In this study, RhoA expression has been investigated in the dorsal/ventral roots of EAN rats by immunohistochemistry. A significant accumulation of RhoA+ cells was observed on Day 12, with a maximum around Day 15, correlating to the clinical severity of EAN. In dorsal/ventral roots of EAN, RhoA+ cells were seen in perivascular areas but also in the parenchyma. Furthermore, double-labelling experiments showed that the major cellular sources of RhoA were reactive macrophages and T cells. In conclusion, this is the first demonstration of the presence of RhoA in the dorsal/ventral roots of EAN. The time courses and cellular sources of RhoA together with the functions of RhoA indicate that RhoA may function to facilitate macrophage and T-cell infiltration in EAN and therefore could be a potential therapeutic target.
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Affiliation(s)
- Zhiren Zhang
- Institute of Brain Research, University of Tuebingen, Tuebingen, Germany.
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Rangel-Mata F, Méndez-Márquez R, Martínez-Cadena G, López-Godínez J, Nishigaki T, Darszon A, García-Soto J. Rho, Rho-kinase, and the actin cytoskeleton regulate the Na+–H+ exchanger in sea urchin eggs. Biochem Biophys Res Commun 2007; 352:264-9. [PMID: 17113032 DOI: 10.1016/j.bbrc.2006.11.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2006] [Accepted: 11/06/2006] [Indexed: 11/26/2022]
Abstract
At fertilization, the sea urchin egg undergoes an internal pH (pHi) increase mediated by a Na+ -H+ exchanger. We used antibodies against the mammalian antiporters NHE1 and NHE3 to characterize this exchanger. In unfertilized eggs, only anti-NHE3 cross-reacted specifically with a protein of 81-kDa, which localized to the plasma membrane and cortical granules. Cytochalasin D, C3 exotoxin (blocker of RhoGTPase function), and Y-27632 (inhibitor of Rho-kinase) prevented the pHi change in fertilized eggs. These inhibitors blocked the first cleavage division of the embryo, but not the cortical granule exocytosis. Thus, the sea urchin egg has an epithelial NHE3-like Na+ -H+ exchanger which can be responsible for the pHi change at fertilization. Determinants of this pHi change can be: (i) the increase of exchangers in the plasma membrane (via cortical granule exocytosis) and (ii) Rho, Rho-kinase, and optimal organization of the actin cytoskeleton as regulators, among others, of the intrinsic activity of the exchanger.
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Affiliation(s)
- Francisco Rangel-Mata
- Instituto de Investigación en Biología Experimental, Facultad de Química, Universidad de Guanajuato, Guanajuato, Gto. 36000, Mexico
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Vogelsgesang M, Pautsch A, Aktories K. C3 exoenzymes, novel insights into structure and action of Rho-ADP-ribosylating toxins. Naunyn Schmiedebergs Arch Pharmacol 2006; 374:347-60. [PMID: 17146673 DOI: 10.1007/s00210-006-0113-y] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2006] [Accepted: 10/18/2006] [Indexed: 12/19/2022]
Abstract
The family of C3-like exoenzymes comprises seven bacterial ADP-ribosyltransferases of different origin. The common hallmark of these exoenzymes is the selective N-ADP-ribosylation of the low molecular mass GTP-binding proteins RhoA, B, and C and inhibition of signal pathways controlled by Rho GTPases. Therefore, C3-like exoenzymes were applied as pharmacological tools for analyses of cellular functions of Rho protein in numerous studies. Recent structural and functional analyses of C3-like exoenzymes provide detailed information on the molecular mechanisms and functional consequences of ADP-ribosylation catalyzed by these toxins. More recently additional non-enzymatic actions of C3-like ADP-ribosyltransferases have been identified showing that C3 transferases from Clostridium botulinum and Clostridium limosum form a GDI-like complex with the Ras-like low molecular mass GTPase Ral without ADP-ribosylation. These results add novel information on the molecular mode of action(s) of C3-like exoenzymes and are discussed in this review.
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Affiliation(s)
- Martin Vogelsgesang
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Albert-Ludwigs-University Freiburg, Otto-Krayer-Haus, Albertstrasse 25, Freiburg, Germany
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Haug G, Barth H, Aktories K. Purification and Activity of the Rho ADP‐Ribosylating Binary C2/C3 Toxin. Methods Enzymol 2006; 406:117-27. [PMID: 16472654 DOI: 10.1016/s0076-6879(06)06010-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
C3 exoenzyme from Clostridium limosum, specifically ADP-ribosylates and inactivates Rho GTPases, but not or much less than Rac and Cdc42. To bypass the poor cell accessibility of the exoenzyme, a chimeric fusion toxin was constructed consisting of C3 exoenzyme and the N-terminal adaptor domain of the enzyme component C2I of the actin-ADP-ribosylating Clostridium botulinum C2 toxin. This fusion toxin C2IN-C3 is transported into cells by interaction with the binding and translocation component (C2II) of C2 toxin. Purification and activity of the chimeric toxin is reported.
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Affiliation(s)
- Gerd Haug
- Albert Ludwigs Universitat Freiburg, Institut fur Experimentelle & Klinische Pharmakologie & Toxikologie, Germany
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39
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Abstract
Rho proteins are master regulators of a large array of cellular functions, including control of cell morphology, cell migration and polarity, transcriptional activation, and cell cycle progression. They are the eukaryotic targets of various bacterial protein toxins and effectors, which activate or inactivate the GTPases. Here Rho-inactivating toxins and effectors are reviewed, including the families of large clostridial cytotoxins and C3-like transferases, which inactivate Rho GTPases by glucosylation and ADP-ribosylation, respectively.
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Affiliation(s)
- K Aktories
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Albertstrasse 25, 79104 Freiburg, Germany.
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40
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Pautsch A, Vogelsgesang M, Tränkle J, Herrmann C, Aktories K. Crystal structure of the C3bot-RalA complex reveals a novel type of action of a bacterial exoenzyme. EMBO J 2005; 24:3670-80. [PMID: 16177825 PMCID: PMC1276701 DOI: 10.1038/sj.emboj.7600813] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2005] [Accepted: 08/22/2005] [Indexed: 12/21/2022] Open
Abstract
C3 exoenzymes from bacterial pathogens ADP-ribosylate and inactivate low-molecular-mass GTPases of the Rho subfamily. Ral, a Ras subfamily GTPase, binds the C3 exoenzymes from Clostridium botulinum and C. limosum with high affinity without being a substrate for ADP ribosylation. In the complex, the ADP-ribosyltransferase activity of C3 is blocked, while binding of NAD and NAD-glycohydrolase activity remain. Here we report the crystal structure of C3 from C. botulinum in a complex with GDP-bound RalA at 1.8 A resolution. C3 binds RalA with a helix-loop-helix motif that is adjacent to the active site. A quaternary complex with NAD suggests a mode for ADP-ribosyltransferase inhibition. Interaction of C3 with RalA occurs at a unique interface formed by the switch-II region, helix alpha3 and the P loop of the GTPase. C3-binding stabilizes the GDP-bound conformation of RalA and blocks nucleotide release. Our data indicate that C. botulinum exoenzyme C3 is a single-domain toxin with bifunctional properties targeting Rho GTPases by ADP ribosylation and Ral by a guanine nucleotide dissociation inhibitor-like effect, which blocks nucleotide exchange.
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Affiliation(s)
- Alexander Pautsch
- Structural Research, Department of Integrated Lead Discovery, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - Martin Vogelsgesang
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie der Universität Freiburg, Otto-Krayer-Haus, Freiburg, Germany
| | - Jens Tränkle
- Physikalische Chemie I, Ruhr-Universität Bochum, Bochum, Germany
| | | | - Klaus Aktories
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie der Universität Freiburg, Otto-Krayer-Haus, Freiburg, Germany
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie der Universität Freiburg, Otto-Krayer-Haus, Albertstrasse 25, 79104 Freiburg, Germany. Tel.: +49 761 203 5301; Fax: +49 761 203 5311; E-mail:
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Conrad S, Schluesener HJ, Trautmann K, Joannin N, Meyermann R, Schwab JM. Prolonged lesional expression of RhoA and RhoB following spinal cord injury. J Comp Neurol 2005; 487:166-75. [PMID: 15880494 DOI: 10.1002/cne.20561] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Inhibition of the small GTPase ras homology protein (Rho) or its downstream target, the Rho-associated kinase (ROCK), has been shown to promote axon regeneration and to improve functional recovery following spinal cord injury (SCI) in the adult rat. Here, we have analyzed the expression of RhoA and RhoB following spinal cord injury in order to assess whether Rho is a possible target for late pharmacological intervention. In control spinal cords, RhoA(+) cells were almost absent, whereas RhoB was localized to some ependymal cells, a few microglia, and some dissociated neurons. In injured spinal cords, RhoA(+) and RhoB(+)cells accumulated at perilesional areas and in the developing necrotic core early after injury at day 1. After reaching their maximum levels (RhoA at day 3; RhoB at day 1), RhoA(+) and RhoB(+) cell numbers remained significantly elevated until day 28. In areas remote from the lesion (> or =0.75 mm), a more discrete accumulation of RhoA(+) and RhoB(+) cells was observed, primarily in areas of ongoing Wallerian degeneration. RhoA and RhoB were predominantly expressed by polymorphonuclear granulocytes, ED1(+) microglia/macrophages, oligodendrocytes, some neurons, and swollen axons/neurites. Furthermore, expression was located to lesional, reactive astrocytes and fibroblastoid cells confined to areas of scar formation. Our experiments have determined that most RhoA(+) and RhoB(+) cells (>70%) are of mononuclear origin. The persistent presence of lesional RhoA(+) and RhoB(+) axon/neurite fibers over a period of 4 weeks after injury suggests that Rho inhibition is a putative therapeutic concept also for delayed intervention after SCI.
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Affiliation(s)
- Sabine Conrad
- Institute of Brain Research, D-72076 Tuebingen, Germany
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42
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Garic-Stankovic A, Hernandez MR, Chiang PJ, Debelak-Kragtorp KA, Flentke GR, Armant DR, Smith SM. Ethanol Triggers Neural Crest Apoptosis through the Selective Activation of a Pertussis Toxin???Sensitive G Protein and a Phospholipase C?????Dependent Ca2+ Transient. Alcohol Clin Exp Res 2005; 29:1237-46. [PMID: 16046880 DOI: 10.1097/01.alc.0000172460.05756.d9] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Alcohol is a potent neurotoxin that triggers the selective apoptosis of neuronal populations in the developing fetus. For neural crest cells, clinically relevant ethanol levels (0.3%) rapidly elicit a phospholipase C (PLC)-dependent intracellular Ca2+ transient that is sufficient to activate apoptosis. We investigated the biochemical origins of this Ca2+ transient. METHODS Three somite chick embryos (stage 8-) were pretreated with agonists and antagonists of PLC signaling pathways before ethanol challenge. The resulting intracellular Ca2+ release was quantified using Fluo-3; apoptosis was assessed using vital dyes. RESULTS Pretreatment of embryos with PLC antagonists U73122 or ET-18-OCH3 confirmed that a phosphoinositide-specific PLC was required for both the ethanol-dependent Ca2+ transient and subsequent cell death. Ethanol rapidly elevated intracellular inositol-1,4,5-trisphosphate [Ins(1,4,5)P3] levels in the rostral portion of the embryo that contains neural crest progenitors. The Ins(1,4,5)P3 receptor antagonist xestospongin C blocked the appearance of the ethanol-dependent Ca2+ transient. Pretreatment with the pan-Galpha protein antagonist GDPbetaS, but not with the tyrosine kinase antagonist genistein, suppressed ethanol's ability to elicit the Ca2+ transient, suggesting that a rise in PLC activity and Ins(1,4,5)P3 concentration originates from stimulation of heterotrimeric G proteins. To probe the identity of this G protein, embryos were treated with G protein antagonists. Pertussis toxin and NF023 suppressed the ethanol-induced Ca2+ transient and subsequent neural crest apoptosis, whereas suramin was weakly inhibitory. C3 exoenzyme was embryolethal over a wide concentration range, consistent with suggestions that Rho family GTPases participate in neural crest development. Galphai2 was identified by immunostaining in the neural crest cells. CONCLUSION We propose a role for Galphai/o protein activation and subsequent interaction of Gbetagamma with PLCbeta in mediating the proapoptotic effects of ethanol upon the developing neural crest.
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Affiliation(s)
- Ana Garic-Stankovic
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison Wisconsin 53706, USA
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43
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Myagmar BE, Umikawa M, Asato T, Taira K, Oshiro M, Hino A, Takei K, Uezato H, Kariya KI. PARG1, a protein-tyrosine phosphatase-associated RhoGAP, as a putative Rap2 effector. Biochem Biophys Res Commun 2005; 329:1046-52. [PMID: 15752761 DOI: 10.1016/j.bbrc.2005.02.069] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2005] [Indexed: 11/29/2022]
Abstract
Rap2 belongs to the Ras family of small GTP-binding proteins, but its specific signaling role is unclear. By yeast two-hybrid screening, we have found that the Caenorhabditis elegans ortholog of Rap2 interacts with a protein containing a Rho-GTPase-activating protein (RhoGAP) domain, ZK669.1a, whose human ortholog PARG1 exhibits RhoGAP activity in vitro. ZK669.1a and PARG1 share a homology region with previously unknown function, designated the ZK669.1a and PARG1 homology (ZPH) region. Here we show that the ZPH region of PARG1 mediates interaction with Rap2. PARG1 interacted with Rap2 in a GTP-dependent manner but not with Ras or Rap1. We also show that PARG1 and its mutant lacking the ZPH region induce typical cytoskeletal changes for Rho inactivation in fibroblasts. Rap2 suppressed this in vivo action of PARG1 but not that of the mutant PARG1. These results suggest that PARG1 is a putative specific effector of Rap2 to regulate Rho.
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Affiliation(s)
- Bat-Erdene Myagmar
- Division of Cell Biology, Graduate School of Medicine, University of the Ryukyus, 207 Uehara, Nishihara-cho, Okinawa 903-0215, Japan
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44
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Grounds HR, Ng DCH, Bogoyevitch MA. Small G-protein Rho is involved in the maintenance of cardiac myocyte morphology. J Cell Biochem 2005; 95:529-42. [PMID: 15786512 DOI: 10.1002/jcb.20441] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The use of small membrane-permeable sequences or protein transduction domains (PTDs) can facilitate the transport of proteins into many cell types. In preliminary studies with the application of three PTDs (penetratin, modified penetratin, and the HIV TAT transduction domains) to cardiac myocytes, we found that the TAT and penetratin sequences showed high efficiency of uptake and low toxicity. Rho has been previously shown to be an important regulator of cytoskeletal organization and morphology in other non-cardiac cell types. To evaluate a role for Rho in cardiac myocyte morphology, we used the TAT-PTD to deliver a RhoA-specific inhibitor, the C3 exoenzyme, to cultured cardiac myocytes. We showed that this incubation with TAT-C3 abolished the basal levels of RhoA activity, demonstrating the efficacy of this treatment. Incubation with TAT-C3 also altered cardiac myocyte morphology so that TAT-C3-treated cells produced multiple projections from the major cell body. This was accompanied by a statistically significant increase in cell size, albeit to a lesser extent than the changes accompanying exposure to the hypertrophic agent, endothelin-1. Furthermore, the change in size of TAT-C3-treated cells was not accompanied by the induction of atrial natriuretic factor (ANF) expression that accompanies the hypertrophy of cardiac myocytes. These results reveal a role for RhoA in the maintenance of normal myocyte morphology.
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Affiliation(s)
- Haslett R Grounds
- Biochemistry and Molecular Biology, University of Western Australia, Crawley, Western Australia 6009, Australia
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45
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Oliveira MJ, Lauwaet T, De Bruyne G, Mareel M, Leroy A. Listeria monocytogenes produces a pro-invasive factor that signals via ErbB2/ErbB3 heterodimers. J Cancer Res Clin Oncol 2004; 131:49-59. [PMID: 15480783 DOI: 10.1007/s00432-004-0601-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2004] [Accepted: 06/25/2004] [Indexed: 01/22/2023]
Abstract
PURPOSE We have previously demonstrated that conditioned medium from bacteria, some of which were isolated from the colon of cancer patients, stimulate cancer cell invasion in vitro through a 13-mer beta-casein-derived peptide. Since invasion signalling pathways are coordinated by the balance between protein kinases and phosphatases, we investigated the effect of conditioned medium from bacteria on the overall cellular tyrosine phosphorylation. METHODS The tyrosine phosphorylation level of HCT-8/E11 human colon cancer cells treated with the pro-invasive conditioned medium of Listeria, prepared on top of collagen type I gels (CM(Coll) Listeria/TSB), were analysed by means of immunoprecipitation and Western blot, with specific anti-phosphotyrosine antibodies. RESULTS We demonstrated that CM(Coll) Listeria/TSB increases the tyrosine phosphorylation level of ErbB2 and ErbB3, members of the epidermal growth factor receptor (EGFR) family, and the association between ErbB3 and the phosphatidylinositol 3-kinase (PI3K) regulatory subunit (p85alpha). CM(Coll) Listeria/TSB-stimulated ErbB3 tyrosine phosphorylation and cancer cell invasion were independent from EGFR expression and activity but dependent on ErbB2 activity. CONCLUSIONS The interaction between Listeria and collagen type I produces, next to the 13-mer peptide, at least another pro-invasive factor that signals via ErbB2/ErbB3 heterodimers.
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Aktories K, Wilde C, Vogelsgesang M. Rho-modifying C3-like ADP-ribosyltransferases. Rev Physiol Biochem Pharmacol 2004; 152:1-22. [PMID: 15372308 DOI: 10.1007/s10254-004-0034-4] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
C3-like exoenzymes comprise a family of seven bacterial ADP-ribosyltransferases, which selectively modify RhoA, B, and C at asparagine-41. Crystal structures of C3 exoenzymes are available, allowing novel insights into the structure-function relationships of these exoenzymes. Because ADP-ribosylation specifically inhibits the biological functions of the low-molecular mass GTPases, C3 exoenzymes are established pharmacological tools to study the cellular functions of Rho GTPases. Recent studies, however, indicate that the functional consequences of C3-induced ADP-ribosylation are more complex than previously suggested. In the present review the basic properties of C3 exoenzymes are briefly summarized and new findings are reviewed.
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Affiliation(s)
- K Aktories
- Institute of Experimental and Clinical Pharmacology and Toxicology, Albert-Ludwigs University Freiburg, Otto-Krayer-Haus, Albertstr. 25, Freiburg, Germany.
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Abstract
The focus of this article is on the cellular uptake mechanism of the family of binary actin ADP-ribosylating toxins from clostridia. These toxins are special-type AB toxins, because they are composed of two nonlinked proteins, which have to assemble on the surface of eukaryotic cells to act cytotoxically. The enzymatically active component (A), ADP-ribosylates G-actin in the cytosol of target cells. This leads to a complete depolymerization of the actin filaments and, thereby, to rounding up of cultured cells. The second component of these toxins, the binding/translocation component (B), mediates the transport of the enzyme component into the cytosol.
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Affiliation(s)
- H Barth
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Albert-Ludwigs-Universität Freiburg, Otto-Krayer-Haus, Albertstrasse 25, 79104, Freiburg, Germany.
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Ahnert-Hilger G, Höltje M, Grosse G, Pickert G, Mucke C, Nixdorf-Bergweiler B, Boquet P, Hofmann F, Just I. Differential effects of Rho GTPases on axonal and dendritic development in hippocampal neurones. J Neurochem 2004; 90:9-18. [PMID: 15198662 DOI: 10.1111/j.1471-4159.2004.02475.x] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Formation of neurites and their differentiation into axons and dendrites requires precisely controlled changes in the cytoskeleton. While small GTPases of the Rho family appear to be involved in this regulation, it is still unclear how Rho function affects axonal and dendritic growth during development. Using hippocampal neurones at defined states of differentiation, we have dissected the function of RhoA in axonal and dendritic growth. Expression of a dominant negative RhoA variant inhibited axonal growth, whereas dendritic growth was promoted. The opposite phenotype was observed when a constitutively active RhoA variant was expressed. Inactivation of Rho by C3-catalysed ADP-ribosylation using C3 isoforms (Clostridium limosum, C3(lim) or Staphylococcus aureus, C3(stau2)), diminished axonal branching. By contrast, extracellularly applied nanomolar concentrations of C3 from C. botulinum (C3(bot)) or enzymatically dead C3(bot) significantly increased axon growth and axon branching. Taken together, axonal development requires activation of RhoA, whereas dendritic development benefits from its inactivation. However, extracellular application of enzymatically active or dead C3(bot) exclusively promotes axonal growth and branching suggesting a novel neurotrophic function of C3 that is independent from its enzymatic activity.
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Affiliation(s)
- G Ahnert-Hilger
- Centrum für Anatomie, Charité Universitätsmedizin, Berlin, AG Funktionelle Zellbiologie, Berlin, Germany.
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Kitaoka Y, Kitaoka Y, Kumai T, Lam TT, Kuribayashi K, Isenoumi K, Munemasa Y, Motoki M, Kobayashi S, Ueno S. Involvement of RhoA and possible neuroprotective effect of fasudil, a Rho kinase inhibitor, in NMDA-induced neurotoxicity in the rat retina. Brain Res 2004; 1018:111-8. [PMID: 15262212 DOI: 10.1016/j.brainres.2004.05.070] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/23/2004] [Indexed: 01/16/2023]
Abstract
RhoA, a key protein involved in cytoskeleton regulation modulating neurogenesis and neural plasticity, has been implicated in a variety of cellular functions including the modulation of N-methyl-D-aspartate (NMDA) receptor activity. We examined its possible involvement in NMDA-induced excitotoxicity in the retina, and evaluated the neuroprotective effect of fasudil, a Rho kinase inhibitor, in this model of neurotoxicity. RhoA protein levels in NMDA-treated retinas were assessed by Western blot analysis and localized by immunohistochemistry. Fasudil (10(-6)-10(-4) M together with 4 x 10(-2) M NMDA) was given intravitreally and its effect was evaluated by counting the number of cells in the ganglion cell layer (GCL), measuring the thickness of the inner plexiform layer (IPL), and measuring retinal Thy-1 mRNA levels at 5 days after injection. Western blot analysis showed a transient increase in the level of retinal RhoA and ROCKII proteins at 1 day after NMDA injection, and that this increment was significantly prevented by simultaneous injection of fasudil. Immunohistochemistry showed that NMDA induced a substantial increase in RhoA immunoreactivity in the GCL and the IPL. Fasudil injection reduced cell loss in the GCL and the reduction in IPL thickness after NMDA injection. The reduction in Thy-1 mRNA levels by NMDA was also significantly attenuated by concomitant injection of fasudil. These results suggest that RhoA and ROCKII are upregulated and may be involved in NMDA-induced retinal neurotoxicity, and that fasudil is neuroprotective against glutamate-related excitotoxicity.
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Affiliation(s)
- Yuka Kitaoka
- Department of Opthalmology, St Marianna University School of Medicine, Kawasaki-shi, Kanagawa, Japan.
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50
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Maddala R, Deng PF, Costello JM, Wawrousek EF, Zigler JS, Rao VP. Impaired cytoskeletal organization and membrane integrity in lens fibers of a Rho GTPase functional knockout transgenic mouse. J Transl Med 2004; 84:679-92. [PMID: 15094715 DOI: 10.1038/labinvest.3700105] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
To investigate the effects of Rho GTPase inactivation on lens fiber cell cytoskeletal and morphological integrity, a transgenic mouse model expressing C3-exoenzyme (a bacterial toxin) in a lens-specific manner was utilized. Cryosections of whole eyes from C3 transgenic mice and littermate controls were stained for F-actin with rhodamine-phalloidin or immunostained for beta-catenin, aquaporin-0 or connexin-50, and confocal images were recorded. Lens fiber cell morphology was examined at both light and electron microscopic levels. To investigate the influence of Rho GTPase inactivation on the profiles of gene expression, cDNA libraries generated from transgenic and littermate control mouse lenses were screened by cDNA microarray analysis. In contrast to the wild-type lens, fiber cells of the transgenic lens were grossly swollen and disorganized, with abnormal membrane architecture. Staining of F-actin, beta-catenin, aquaporin-0 and connexin-50 was reduced dramatically in the C3 transgenic lens as compared to controls. Western blot analysis and cDNA microarray analysis did not reveal any noticeable decreases in actin, beta-catenin and aquaporin-0 protein levels or expression in C3 transgenic lenses, indicating that altered cytoskeletal organization in response to Rho GTPase inactivation might underlie the noted changes in staining for these proteins. Additionally, cDNA microarray analysis of C3 lens revealed altered expression (at least two-fold, compared to littermate controls) of 44 genes. These include genes encoding extracellular matrix and basement membrane proteins, cell survival and apoptotic pathways, and ion and protein transport. These data indicate that disruption of Rho GTPase function in the developing mouse lens results in abnormal cytoskeletal organization, fiber cell interactions, impaired lens fiber cell morphology and altered gene expression of cellular proteins involved in diverse functions. This work reveals that the morphological and cytoskeletal abnormalities triggered upon Rho GTPase inactivation in lens could be one of the important insults associated with cataract formation in C3 transgenic mouse lens.
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Affiliation(s)
- Rupalatha Maddala
- Department of Ophthalmology, Duke University Medical Center, Durham, NC 27710, USA
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