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Zhang D, Yang X, Wen Z, Li Z, Zhang X, Zhong C, She J, Zhang Q, Zhang H, Li W, Zhao X, Xu M, Su Z, Li D, Dinesh-Kumar SP, Zhang Y. Proxitome profiling reveals a conserved SGT1-NSL1 signaling module that activates NLR-mediated immunity. MOLECULAR PLANT 2024; 17:1369-1391. [PMID: 39066482 DOI: 10.1016/j.molp.2024.07.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2024] [Revised: 06/13/2024] [Accepted: 07/22/2024] [Indexed: 07/28/2024]
Abstract
Suppressor of G2 allele of skp1 (SGT1) is a highly conserved eukaryotic protein that plays a vital role in growth, development, and immunity in both animals and plants. Although some SGT1 interactors have been identified, the molecular regulatory network of SGT1 remains unclear. SGT1 serves as a co-chaperone to stabilize protein complexes such as the nucleotide-binding leucine-rich repeat (NLR) class of immune receptors, thereby positively regulating plant immunity. SGT1 has also been found to be associated with the SKP1-Cullin-F-box (SCF) E3 ubiquitin ligase complex. However, whether SGT1 targets immune repressors to coordinate plant immune activation remains elusive. In this study, we constructed a toolbox for TurboID- and split-TurboID-based proximity labeling (PL) assays in Nicotiana benthamiana and used the PL toolbox to explore the SGT1 interactome during pre- and post-immune activation. The comprehensive SGT1 interactome network we identified highlights a dynamic shift from proteins associated with plant development to those linked with plant immune responses. We found that SGT1 interacts with Necrotic Spotted Lesion 1 (NSL1), which negatively regulates salicylic acid-mediated defense by interfering with the nucleocytoplasmic trafficking of non-expressor of pathogenesis-related genes 1 (NPR1) during N NLR-mediated response to tobacco mosaic virus. SGT1 promotes the SCF-dependent degradation of NSL1 to facilitate immune activation, while salicylate-induced protein kinase-mediated phosphorylation of SGT1 further potentiates this process. Besides N NLR, NSL1 also functions in several other NLR-mediated immunity. Collectively, our study unveils the regulatory landscape of SGT1 and reveals a novel SGT1-NSL1 signaling module that orchestrates plant innate immunity.
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Affiliation(s)
- Dingliang Zhang
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, Beijing 100193, China; State Key Laboratory of Plant Environmental Resilience, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China
| | - Xinxin Yang
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Zhiyan Wen
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Zhen Li
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Xinyu Zhang
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Chenchen Zhong
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Jiajie She
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Qianshen Zhang
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - He Zhang
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Wenli Li
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Xiaoyun Zhao
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Mingliang Xu
- State Key Laboratory of Plant Environmental Resilience, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China
| | - Zhen Su
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Dawei Li
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Savithramma P Dinesh-Kumar
- Department of Plant Biology and The Genome Center, College of Biological Sciences, University of California, Davis, Davis, CA 95616, USA.
| | - Yongliang Zhang
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
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2
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Smith LC, Crow RS, Franchi N, Schrankel CS. The echinoid complement system inferred from genome sequence searches. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2023; 140:104584. [PMID: 36343741 DOI: 10.1016/j.dci.2022.104584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 10/01/2022] [Accepted: 10/31/2022] [Indexed: 06/16/2023]
Abstract
The vertebrate complement cascade is an essential host protection system that functions at the intersection of adaptive and innate immunity. However, it was originally assumed that complement was present only in vertebrates because it was activated by antibodies and functioned with adaptive immunity. Subsequently, the identification of the key component, SpC3, in sea urchins plus a wide range of other invertebrates significantly expanded the concepts of how complement functions. Because there are few reports on the echinoid complement system, an alternative approach to identify complement components in echinoderms is to search the deduced proteins encoded in the genomes. This approach identified known and putative members of the lectin and alternative activation pathways, but members of the terminal pathway are absent. Several types of complement receptors are encoded in the genomes. Complement regulatory proteins composed of complement control protein (CCP) modules are identified that may control the activation pathways and the convertases. Other regulatory proteins without CCP modules are also identified, however regulators of the terminal pathway are absent. The expansion of genes encoding proteins with Macpf domains is noteworthy because this domain is a signature of perforin and proteins in the terminal pathway. The results suggest that the major functions of the echinoid complement system are detection of foreign targets by the proteins that initiate the activation pathways resulting in opsonization by SpC3b fragments to augment phagocytosis and destruction of the foreign targets by the immune cells.
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Affiliation(s)
- L Courtney Smith
- Department of Biological Sciences, George Washington University, Washington DC, USA.
| | - Ryley S Crow
- Department of Biological Sciences, George Washington University, Washington DC, USA
| | - Nicola Franchi
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Catherine S Schrankel
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California, La Jolla, CA, USA
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3
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Yu X, Ni T, Munson G, Zhang P, Gilbert RJC. Cryo-EM structures of perforin-2 in isolation and assembled on a membrane suggest a mechanism for pore formation. EMBO J 2022; 41:e111857. [PMID: 36245269 PMCID: PMC9713709 DOI: 10.15252/embj.2022111857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 07/29/2022] [Accepted: 09/09/2022] [Indexed: 01/15/2023] Open
Abstract
Perforin-2 (PFN2, MPEG1) is a key pore-forming protein in mammalian innate immunity restricting intracellular bacteria proliferation. It forms a membrane-bound pre-pore complex that converts to a pore-forming structure upon acidification; but its mechanism of conformational transition has been debated. Here we used cryo-electron microscopy, tomography and subtomogram averaging to determine structures of PFN2 in pre-pore and pore conformations in isolation and bound to liposomes. In isolation and upon acidification, the pre-assembled complete pre-pore rings convert to pores in both flat ring and twisted conformations. On membranes, in situ assembled PFN2 pre-pores display various degrees of completeness; whereas PFN2 pores are mainly incomplete arc structures that follow the same subunit packing arrangements as found in isolation. Both assemblies on membranes use their P2 β-hairpin for binding to the lipid membrane surface. Overall, these structural snapshots suggest a molecular mechanism for PFN2 pre-pore to pore transition on a targeted membrane, potentially using the twisted pore as an intermediate or alternative state to the flat conformation, with the capacity to cause bilayer distortion during membrane insertion.
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Affiliation(s)
- Xiulian Yu
- Division of Structural Biology, Wellcome Centre for Human GeneticsUniversity of OxfordOxfordUK
- Calleva Research Centre for Evolution and Human Sciences, Magdalen CollegeUniversity of OxfordOxfordUK
| | - Tao Ni
- Division of Structural Biology, Wellcome Centre for Human GeneticsUniversity of OxfordOxfordUK
- Present address:
School of Biomedical Sciences, LKS Faculty of MedicineThe University of Hong KongPokfulamHong Kong SARChina
| | - George Munson
- Department of Microbiology and ImmunologyUniversity of Miami Miller School of MedicineMiamiFLUSA
| | - Peijun Zhang
- Division of Structural Biology, Wellcome Centre for Human GeneticsUniversity of OxfordOxfordUK
- Diamond Light SourceHarwell Science and Innovation CampusDidcotUK
- Chinese Academy of Medical Sciences Oxford InstituteUniversity of OxfordOxfordUK
| | - Robert J C Gilbert
- Division of Structural Biology, Wellcome Centre for Human GeneticsUniversity of OxfordOxfordUK
- Calleva Research Centre for Evolution and Human Sciences, Magdalen CollegeUniversity of OxfordOxfordUK
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Junglas B, Axt A, Siebenaller C, Sonel H, Hellmann N, Weber SAL, Schneider D. Membrane destabilization and pore formation induced by the Synechocystis IM30 protein. Biophys J 2022; 121:3411-3421. [PMID: 35986519 PMCID: PMC9515227 DOI: 10.1016/j.bpj.2022.08.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 07/21/2022] [Accepted: 08/15/2022] [Indexed: 11/18/2022] Open
Abstract
The inner membrane-associated protein of 30 kDa (IM30) is essential in chloroplasts and cyanobacteria. The spatio-temporal cellular localization of the protein appears to be highly dynamic and triggered by internal as well as external stimuli, mainly light intensity. The soluble fraction of the protein is localized in the cyanobacterial cytoplasm or the chloroplast stroma, respectively. Additionally, the protein attaches to the thylakoid membrane as well as to the chloroplast inner envelope or the cyanobacterial cytoplasmic membrane, respectively, especially under conditions of membrane stress. IM30 is involved in thylakoid membrane biogenesis and/or maintenance, where it either stabilizes membranes and/or triggers membrane-fusion processes. These apparently contradicting functions have to be tightly controlled and separated spatiotemporally in chloroplasts and cyanobacteria. IM30's fusogenic activity depends on Mg2+ binding to IM30; yet, it still is unclear how Mg2+-loaded IM30 interacts with membranes and promotes membrane fusion. Here, we show that the interaction of Mg2+ with IM30 results in increased binding of IM30 to native, as well as model, membranes. Via atomic force microscopy in liquid, IM30-induced bilayer defects were observed in solid-supported bilayers in the presence of Mg2+. These structures differ dramatically from the membrane-stabilizing carpet structures that were previously observed in the absence of Mg2+. Thus, Mg2+-induced alterations of the IM30 structure switch the IM30 activity from a membrane-stabilizing to a membrane-destabilizing function, a crucial step in membrane fusion.
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Affiliation(s)
- Benedikt Junglas
- Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Amelie Axt
- Max Planck-Institute for Polymer Research, Mainz, Germany; Institute of Physics, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Carmen Siebenaller
- Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Hilal Sonel
- Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Nadja Hellmann
- Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Stefan A L Weber
- Max Planck-Institute for Polymer Research, Mainz, Germany; Institute of Physics, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Dirk Schneider
- Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, Mainz, Germany; Institute of Molecular Physiology, Johannes Gutenberg University Mainz, Mainz, Germany.
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5
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Pereira JM, Xu S, Leong JM, Sousa S. The Yin and Yang of Pneumolysin During Pneumococcal Infection. Front Immunol 2022; 13:878244. [PMID: 35529870 PMCID: PMC9074694 DOI: 10.3389/fimmu.2022.878244] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 03/23/2022] [Indexed: 12/15/2022] Open
Abstract
Pneumolysin (PLY) is a pore-forming toxin produced by the human pathobiont Streptococcus pneumoniae, the major cause of pneumonia worldwide. PLY, a key pneumococcal virulence factor, can form transmembrane pores in host cells, disrupting plasma membrane integrity and deregulating cellular homeostasis. At lytic concentrations, PLY causes cell death. At sub-lytic concentrations, PLY triggers host cell survival pathways that cooperate to reseal the damaged plasma membrane and restore cell homeostasis. While PLY is generally considered a pivotal factor promoting S. pneumoniae colonization and survival, it is also a powerful trigger of the innate and adaptive host immune response against bacterial infection. The dichotomy of PLY as both a key bacterial virulence factor and a trigger for host immune modulation allows the toxin to display both "Yin" and "Yang" properties during infection, promoting disease by membrane perforation and activating inflammatory pathways, while also mitigating damage by triggering host cell repair and initiating anti-inflammatory responses. Due to its cytolytic activity and diverse immunomodulatory properties, PLY is integral to every stage of S. pneumoniae pathogenesis and may tip the balance towards either the pathogen or the host depending on the context of infection.
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Affiliation(s)
- Joana M. Pereira
- i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- Molecular and Cellular (MC) Biology PhD Program, ICBAS - Instituto de Ciência Biomédicas Abel Salazar, University of Porto, Porto, Portugal
| | - Shuying Xu
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, United States
- Graduate Program in Immunology, Tufts Graduate School of Biomedical Sciences, Boston, MA, United States
| | - John M. Leong
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, United States
| | - Sandra Sousa
- i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
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6
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Kulma M, Anderluh G. Beyond pore formation: reorganization of the plasma membrane induced by pore-forming proteins. Cell Mol Life Sci 2021; 78:6229-6249. [PMID: 34387717 PMCID: PMC11073440 DOI: 10.1007/s00018-021-03914-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 07/09/2021] [Accepted: 08/03/2021] [Indexed: 12/23/2022]
Abstract
Pore-forming proteins (PFPs) are a heterogeneous group of proteins that are expressed and secreted by a wide range of organisms. PFPs are produced as soluble monomers that bind to a receptor molecule in the host cell membrane. They then assemble into oligomers that are incorporated into the lipid membrane to form transmembrane pores. Such pore formation alters the permeability of the plasma membrane and is one of the most common mechanisms used by PFPs to destroy target cells. Interestingly, PFPs can also indirectly manipulate diverse cellular functions. In recent years, increasing evidence indicates that the interaction of PFPs with lipid membranes is not only limited to pore-induced membrane permeabilization but is also strongly associated with extensive plasma membrane reorganization. This includes lateral rearrangement and deformation of the lipid membrane, which can lead to the disruption of target cell function and finally death. Conversely, these modifications also constitute an essential component of the membrane repair system that protects cells from the lethal consequences of pore formation. Here, we provide an overview of the current knowledge on the changes in lipid membrane organization caused by PFPs from different organisms.
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Affiliation(s)
- Magdalena Kulma
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1001, Ljubljana, Slovenia.
| | - Gregor Anderluh
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1001, Ljubljana, Slovenia
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7
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The molecular mechanisms of listeriolysin O-induced lipid membrane damage. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2021; 1863:183604. [PMID: 33722646 DOI: 10.1016/j.bbamem.2021.183604] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 03/05/2021] [Accepted: 03/05/2021] [Indexed: 12/22/2022]
Abstract
Listeria monocytogenes is an intracellular food-borne pathogen that causes listeriosis, a severe and potentially life-threatening disease. Listeria uses a number of virulence factors to proliferate and spread to various cells and tissues. In this process, three bacterial virulence factors, the pore-forming protein listeriolysin O and phospholipases PlcA and PlcB, play a crucial role. Listeriolysin O belongs to a family of cholesterol-dependent cytolysins that are mostly expressed by gram-positive bacteria. Its unique structural features in an otherwise conserved three-dimensional fold, such as the acidic triad and proline-glutamate-serine-threonine-like sequence, enable the regulation of its intracellular activity as well as distinct extracellular functions. The stability of listeriolysin O is pH- and temperature-dependent, and this provides another layer of control of its activity in cells. Moreover, many recent studies have demonstrated a unique mechanism of pore formation by listeriolysin O, i.e., the formation of arc-shaped oligomers that can subsequently fuse to form membrane defects of various shapes and sizes. During listerial invasion of host cells, these membrane defects can disrupt phagosome membranes, allowing bacteria to escape into the cytosol and rapidly multiply. The activity of listeriolysin O is profoundly dependent on the amount and accessibility of cholesterol in the lipid membrane, which can be modulated by the phospholipase PlcB. All these prominent features of listeriolysin O play a role during different stages of the L. monocytogenes life cycle by promoting the proliferation of the pathogen while mitigating excessive damage to its replicative niche in the cytosol of the host cell.
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Gilbert RJC. Electron microscopy as a critical tool in the determination of pore forming mechanisms in proteins. Methods Enzymol 2021; 649:71-102. [PMID: 33712203 DOI: 10.1016/bs.mie.2021.01.034] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Electron microscopy has consistently played an important role in the description of pore-forming protein systems. The discovery of pore-forming proteins has depended on visualization of the structural pores formed by their oligomeric protein complexes, and as electron microscopy has advanced technologically so has the degree of insight it has been able to give. This review considers a large number of published studies of pore-forming complexes in prepore and pore states determined using single-particle cryo-electron microscopy. Sample isolation and preparation, imaging and image analysis, structure determination and optimization of results are all discussed alongside challenges which pore-forming proteins particularly present. The review also considers the use made of cryo-electron tomography to study pores within their membrane environment and which will prove an increasingly important approach for the future.
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Affiliation(s)
- Robert J C Gilbert
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, United Kingdom.
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9
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Jiang K, Yin Z, Zhang Y, Xu Q, Yu Y, Cong W, Yan X, Nie H. Genome-wide investigation and expression analysis of MACPF gene family reveals its immune role in response to bacterial challenge of Manila clam. Genomics 2021; 113:1136-1145. [PMID: 33639237 DOI: 10.1016/j.ygeno.2021.02.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Revised: 01/14/2021] [Accepted: 02/17/2021] [Indexed: 01/26/2023]
Abstract
In this study, 18 MACPF genes (RpMACPF) were identified and classed into three types (Macrophage-expressed gene 1, Apextrin, and MACPF domain contain protein) based on gene structure and phylogenetic relationship in R. philippinarum. The length of RpMACPF proteins varied from 287 to 785 amino acids. The molecular weights and Theoretical PI values ranged from 3.2 kDa to 8.7 kDa and 4.7 to 8.6, respectively. RNA-seq data analysis revealed that 14 of 18 RpMACPF genes were highly expressed at the pediveliger larvae stage indicate RpMACPF might contribute to the early development and metamorphosis processes of the R. philippinarum. Besides, we found RpMACPF genes were significantly regulated by pathogen-associated molecular patterns (PAMPs) and Vibrio parahemolyticus, which indicates RpMACPF genes may play significant roles in response to invading pathogens. The results obtained in this work will provide valuable insight into the immune function of MACPF gene in R. philippinarum.
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Affiliation(s)
- Kunyin Jiang
- School of Fisheries and Life Science, Dalian Ocean University, 116023 Dalian, China; Engineering Research Center of Shellfish Culture and Breeding in Liaoning Province, Dalian Ocean University, 116023 Dalian, China
| | - Zhihui Yin
- School of Fisheries and Life Science, Dalian Ocean University, 116023 Dalian, China; Engineering Research Center of Shellfish Culture and Breeding in Liaoning Province, Dalian Ocean University, 116023 Dalian, China
| | - Yanming Zhang
- School of Fisheries and Life Science, Dalian Ocean University, 116023 Dalian, China; Engineering Research Center of Shellfish Culture and Breeding in Liaoning Province, Dalian Ocean University, 116023 Dalian, China
| | - Qiaoyue Xu
- School of Fisheries and Life Science, Dalian Ocean University, 116023 Dalian, China; Engineering Research Center of Shellfish Culture and Breeding in Liaoning Province, Dalian Ocean University, 116023 Dalian, China
| | - Yongchao Yu
- Rongcheng Marine Economic Development Center, 264300 Rongcheng, China
| | - Wanlin Cong
- Rongcheng Marine Economic Development Center, 264300 Rongcheng, China
| | - Xiwu Yan
- School of Fisheries and Life Science, Dalian Ocean University, 116023 Dalian, China; Engineering Research Center of Shellfish Culture and Breeding in Liaoning Province, Dalian Ocean University, 116023 Dalian, China
| | - Hongtao Nie
- School of Fisheries and Life Science, Dalian Ocean University, 116023 Dalian, China; Engineering Research Center of Shellfish Culture and Breeding in Liaoning Province, Dalian Ocean University, 116023 Dalian, China.
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10
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Shivappagowdar A, Garg S, Srivastava A, Hada RS, Kalia I, Singh AP, Garg LC, Pati S, Singh S. Pathogenic Pore Forming Proteins of Plasmodium Triggers the Necrosis of Endothelial Cells Attributed to Malaria Severity. Toxins (Basel) 2021; 13:toxins13010062. [PMID: 33467515 PMCID: PMC7839052 DOI: 10.3390/toxins13010062] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 11/05/2020] [Accepted: 11/08/2020] [Indexed: 11/17/2022] Open
Abstract
Severe malaria caused by Plasmodium falciparum poses a major global health problem with high morbidity and mortality. P. falciparum harbors a family of pore-forming proteins (PFPs), known as perforin like proteins (PLPs), which are structurally equivalent to prokaryotic PFPs. These PLPs are secreted from the parasites and, they contribute to disease pathogenesis by interacting with host cells. The severe malaria pathogenesis is associated with the dysfunction of various barrier cells, including endothelial cells (EC). Several factors, including PLPs secreted by parasites, contribute to the host cell dysfunction. Herein, we have tested the hypothesis that PLPs mediate dysfunction of barrier cells and might have a role in disease pathogenesis. We analyzed various dysfunctions in barrier cells following rPLP2 exposure and demonstrate that it causes an increase in intracellular Ca2+ levels. Additionally, rPLP2 exposed barrier cells displayed features of cell death, including Annexin/PI positivity, depolarized the mitochondrial membrane potential, and ROS generation. We have further performed the time-lapse video microscopy of barrier cells and found that the treatment of rPLP2 triggers their membrane blebbing. The cytoplasmic localization of HMGB1, a marker of necrosis, further confirmed the necrotic type of cell death. This study highlights the role of parasite factor PLP in endothelial dysfunction and provides a rationale for the design of adjunct therapies against severe malaria.
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Affiliation(s)
- Abhishek Shivappagowdar
- Department of Life Science, School of Natural Sciences, Shiv Nadar University, Chithera, Gautam Buddha Nagar, Uttar Pradesh 201314, India; (A.S.); (A.S.); (R.S.H.); (S.P.)
| | - Swati Garg
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi 110067, India;
| | - Akriti Srivastava
- Department of Life Science, School of Natural Sciences, Shiv Nadar University, Chithera, Gautam Buddha Nagar, Uttar Pradesh 201314, India; (A.S.); (A.S.); (R.S.H.); (S.P.)
| | - Rahul S. Hada
- Department of Life Science, School of Natural Sciences, Shiv Nadar University, Chithera, Gautam Buddha Nagar, Uttar Pradesh 201314, India; (A.S.); (A.S.); (R.S.H.); (S.P.)
| | - Inderjeet Kalia
- Infectious Disease Lab, National Institute of Immunology, New Delhi 110067, India; (I.K.); (A.P.S.)
| | - Agam P. Singh
- Infectious Disease Lab, National Institute of Immunology, New Delhi 110067, India; (I.K.); (A.P.S.)
| | - Lalit C. Garg
- Gene Regulation Laboratory, National Institute of Immunology, New Delhi 110067, India;
| | - Soumya Pati
- Department of Life Science, School of Natural Sciences, Shiv Nadar University, Chithera, Gautam Buddha Nagar, Uttar Pradesh 201314, India; (A.S.); (A.S.); (R.S.H.); (S.P.)
| | - Shailja Singh
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi 110067, India;
- Correspondence:
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11
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Pore-forming proteins: From defense factors to endogenous executors of cell death. Chem Phys Lipids 2020; 234:105026. [PMID: 33309552 DOI: 10.1016/j.chemphyslip.2020.105026] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 12/07/2020] [Accepted: 12/07/2020] [Indexed: 02/06/2023]
Abstract
Pore-forming proteins (PFPs) and small antimicrobial peptides (AMPs) represent a large family of molecules with the common ability to punch holes in cell membranes to alter their permeability. They play a fundamental role as infectious bacteria's defensive tools against host's immune system and as executors of endogenous machineries of regulated cell death in eukaryotic cells. Despite being highly divergent in primary sequence and 3D structure, specific folds of pore-forming domains have been conserved. In fact, pore formation is considered an ancient mechanism that takes place through a general multistep process involving: membrane partitioning and insertion, oligomerization and pore formation. However, different PFPs and AMPs assemble and form pores following different mechanisms that could end up either in the formation of protein-lined or protein-lipid pores. In this review, we analyze the current findings in the mechanism of action of different PFPs and AMPs that support a wide role of membrane pore formation in nature. We also provide the newest insights into the development of state-of-art techniques that have facilitated the characterization of membrane pores. To understand the physiological role of these peptides/proteins or develop clinical applications, it is essential to uncover the molecular mechanism of how they perforate membranes.
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12
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Flores‐Romero H, Ros U, Garcia‐Saez AJ. Pore formation in regulated cell death. EMBO J 2020; 39:e105753. [PMID: 33124082 PMCID: PMC7705454 DOI: 10.15252/embj.2020105753] [Citation(s) in RCA: 112] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 07/13/2020] [Accepted: 10/06/2020] [Indexed: 12/21/2022] Open
Abstract
The discovery of alternative signaling pathways that regulate cell death has revealed multiple strategies for promoting cell death with diverse consequences at the tissue and organism level. Despite the divergence in the molecular components involved, membrane permeabilization is a common theme in the execution of regulated cell death. In apoptosis, the permeabilization of the outer mitochondrial membrane by BAX and BAK releases apoptotic factors that initiate the caspase cascade and is considered the point of no return in cell death commitment. Pyroptosis and necroptosis also require the perforation of the plasma membrane at the execution step, which involves Gasdermins in pyroptosis, and MLKL in the case of necroptosis. Although BAX/BAK, Gasdermins and MLKL share certain molecular features like oligomerization, they form pores in different cellular membranes via distinct mechanisms. Here, we compare and contrast how BAX/BAK, Gasdermins, and MLKL alter membrane permeability from a structural and biophysical perspective and discuss the general principles of membrane permeabilization in the execution of regulated cell death.
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Affiliation(s)
- Hector Flores‐Romero
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany
| | - Uris Ros
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany
| | - Ana J Garcia‐Saez
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany
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13
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Bayly-Jones C, Pang SS, Spicer BA, Whisstock JC, Dunstone MA. Ancient but Not Forgotten: New Insights Into MPEG1, a Macrophage Perforin-Like Immune Effector. Front Immunol 2020; 11:581906. [PMID: 33178209 PMCID: PMC7593815 DOI: 10.3389/fimmu.2020.581906] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 09/25/2020] [Indexed: 12/29/2022] Open
Abstract
Macrophage-expressed gene 1 [MPEG1/Perforin-2 (PRF2)] is an ancient metazoan protein belonging to the Membrane Attack Complex/Perforin (MACPF) branch of the MACPF/Cholesterol Dependent Cytolysin (CDC) superfamily of pore-forming proteins (PFPs). MACPF/CDC proteins are a large and extremely diverse superfamily that forms large transmembrane aqueous channels in target membranes. In humans, MACPFs have known roles in immunity and development. Like perforin (PRF) and the membrane attack complex (MAC), MPEG1 is also postulated to perform a role in immunity. Indeed, bioinformatic studies suggest that gene duplications of MPEG1 likely gave rise to PRF and MAC components. Studies reveal partial or complete loss of MPEG1 causes an increased susceptibility to microbial infection in both cells and animals. To this end, MPEG1 expression is upregulated in response to proinflammatory signals such as tumor necrosis factor α (TNFα) and lipopolysaccharides (LPS). Furthermore, germline mutations in MPEG1 have been identified in connection with recurrent pulmonary mycobacterial infections in humans. Structural studies on MPEG1 revealed that it can form oligomeric pre-pores and pores. Strikingly, the unusual domain arrangement within the MPEG1 architecture suggests a novel mechanism of pore formation that may have evolved to guard against unwanted lysis of the host cell. Collectively, the available data suggest that MPEG1 likely functions as an intracellular pore-forming immune effector. Herein, we review the current understanding of MPEG1 evolution, regulation, and function. Furthermore, recent structural studies of MPEG1 are discussed, including the proposed mechanisms of action for MPEG1 bactericidal activity. Lastly limitations, outstanding questions, and implications of MPEG1 models are explored in the context of the broader literature and in light of newly available structural data.
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Affiliation(s)
- Charles Bayly-Jones
- ARC Centre of Excellence in Advanced Molecular Imaging, Monash University, Melbourne, VIC, Australia.,Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, Australia
| | - Siew Siew Pang
- ARC Centre of Excellence in Advanced Molecular Imaging, Monash University, Melbourne, VIC, Australia.,Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, Australia
| | - Bradley A Spicer
- ARC Centre of Excellence in Advanced Molecular Imaging, Monash University, Melbourne, VIC, Australia.,Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, Australia
| | - James C Whisstock
- ARC Centre of Excellence in Advanced Molecular Imaging, Monash University, Melbourne, VIC, Australia.,Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, Australia.,John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia
| | - Michelle A Dunstone
- ARC Centre of Excellence in Advanced Molecular Imaging, Monash University, Melbourne, VIC, Australia.,Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, Australia
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14
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Dubey M, Jensen DF, Karlsson M. Functional characterization of the AGL1 aegerolysin in the mycoparasitic fungus Trichoderma atroviride reveals a role in conidiation and antagonism. Mol Genet Genomics 2020; 296:131-140. [PMID: 33052533 PMCID: PMC7840653 DOI: 10.1007/s00438-020-01732-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 09/29/2020] [Indexed: 11/28/2022]
Abstract
Aegerolysins are small secreted pore-forming proteins that are found in both prokaryotes and eukaryotes. The role of aegerolysins in sporulation, fruit body formation, and in lysis of cellular membrane is suggested in fungi. The aim of the present study was to characterize the biological function of the aegerolysin gene agl1 in the mycoparasitic fungus Trichoderma atroviride, used for biological control of plant diseases. Gene expression analysis showed higher expression of agl1 during conidiation and during growth in medium supplemented with cell wall material from the plant pathogenic fungus Rhizoctonia solani as the sole carbon source. Expression of agl1 was supressed under iron-limiting condition, while agl1 transcript was not detected during T. atroviride interactions with the prey fungi Botrytis cinerea or R. solani. Phenotypic analysis of agl1 deletion strains (Δagl1) showed reduced conidiation compared to T. atroviride wild type, thus suggesting the involvement of AGL1 in conidiation. Furthermore, the Δagl1 strains display reduced antagonism towards B. cinerea and R. solani based on a secretion assay, although no difference was detected during direct interactions. These data demonstrate the role of AGL1 in conidiation and antagonism in the mycoparasitic fungus T. atroviride.
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Affiliation(s)
- Mukesh Dubey
- Department of Forest Mycology and Plant Pathology, Uppsala Biocenter, Swedish University of Agricultural Sciences, P.O. Box 7026, 75007, Uppsala, Sweden.
| | - Dan Funck Jensen
- Department of Forest Mycology and Plant Pathology, Uppsala Biocenter, Swedish University of Agricultural Sciences, P.O. Box 7026, 75007, Uppsala, Sweden
| | - Magnus Karlsson
- Department of Forest Mycology and Plant Pathology, Uppsala Biocenter, Swedish University of Agricultural Sciences, P.O. Box 7026, 75007, Uppsala, Sweden
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15
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Vötsch D, Willenborg M, Oelemann WM, Brogden G, Valentin-Weigand P. Membrane Binding, Cellular Cholesterol Content and Resealing Capacity Contribute to Epithelial Cell Damage Induced by Suilysin of Streptococcus suis. Pathogens 2019; 9:pathogens9010033. [PMID: 31905867 PMCID: PMC7168673 DOI: 10.3390/pathogens9010033] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 12/19/2019] [Accepted: 12/24/2019] [Indexed: 12/31/2022] Open
Abstract
Streptococcus (S.) suis is a major cause of economic losses in the pig industry worldwide and is an emerging zoonotic pathogen. One important virulence-associated factor is suilysin (SLY), a toxin that belongs to the family of cholesterol-dependent pore-forming cytolysins (CDC). However, the precise role of SLY in host–pathogen interactions is still unclear. Here, we investigated the susceptibility of different respiratory epithelial cells to SLY, including immortalized cell lines (HEp-2 and NPTr cells), which are frequently used in in vitro studies on S. suis virulence mechanisms, as well as primary porcine respiratory cells, which represent the first line of barrier during S. suis infections. SLY-induced cell damage was determined by measuring the release of lactate dehydrogenase after infection with a virulent S. suis serotype 2 strain, its isogenic SLY-deficient mutant strain, or treatment with the recombinant protein. HEp-2 cells were most susceptible, whereas primary epithelial cells were hardly affected by the toxin. This prompted us to study possible explanations for these differences. We first investigated the binding capacity of SLY using flow cytometry analysis. Since binding and pore-formation of CDC is dependent on the membrane composition, we also determined the cellular cholesterol content of the different cell types using TLC and HPLC. Finally, we examined the ability of those cells to reseal SLY-induced pores using flow cytometry analysis. Our results indicated that the amount of membrane-bound SLY, the cholesterol content of the cells, as well as their resealing capacity all affect the susceptibility of the different cells regarding the effects of SLY. These findings underline the differences of in vitro pathogenicity models and may further help to dissect the biological role of SLY during S. suis infections.
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Affiliation(s)
- Désirée Vötsch
- Institute for Microbiology, University of Veterinary Medicine Hannover, 30173 Hannover, Germany; (D.V.); (M.W.)
| | - Maren Willenborg
- Institute for Microbiology, University of Veterinary Medicine Hannover, 30173 Hannover, Germany; (D.V.); (M.W.)
| | - Walter M.R. Oelemann
- Institute for Microbiology, University of Veterinary Medicine Hannover, 30173 Hannover, Germany; (D.V.); (M.W.)
- Departamento de Imunologia, Instituto de Microbiologia Paulo Góes, Universidade Federal do Rio de Janeiro (UFRJ), 21941-901 Rio de Janeiro, Brazil
| | - Graham Brogden
- Department of Physiological Chemistry, University for Veterinary Medicine Hannover, 30559 Hannover, Germany;
| | - Peter Valentin-Weigand
- Institute for Microbiology, University of Veterinary Medicine Hannover, 30173 Hannover, Germany; (D.V.); (M.W.)
- Correspondence: ; Tel.: +49-(0)511-856-7362
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16
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Novak M, Čepin U, Hodnik V, Narat M, Jamnik M, Kraševec N, Sepčić K, Anderluh G. Functional studies of aegerolysin and MACPF-like proteins in Aspergillus niger. Mol Microbiol 2019; 112:1253-1269. [PMID: 31376198 DOI: 10.1111/mmi.14360] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/28/2019] [Indexed: 12/21/2022]
Abstract
Proteins of the aegerolysin family have a high abundance in Fungi. Due to their specific binding to membrane lipids, and their membrane-permeabilization potential in concert with protein partner(s) belonging to a membrane-attack-complex/perforin (MACPF) superfamily, they were proposed as useful tools in different biotechnological and biomedical applications. In this work, we performed functional studies on expression of the genes encoding aegerolysin and MACPF-like proteins in Aspergillus niger. Our results suggest the sporulation process being crucial for strong induction of the expression of all these genes. However, deletion of either of the aegerolysin genes did not influence the growth, development, sporulation efficiency and phenotype of the mutants, indicating that aegerolysins are not key factors in the sporulation process. In all our expression studies we noticed a strong correlation in the expression of one aegerolysin and MACPF-like gene. Aegerolysins were confirmed to be secreted from the fungus. We also showed the specific interaction of a recombinant A. niger aegerolysin with an invertebrate-specific membrane sphingolipid. Moreover, using this protein labelled with mCherry we successfully stained insect cells membranes containing this particular sphingolipid. Our combined results suggest, that aegerolysins in this species, and probably also in other aspergilli, could be involved in defence against predators.
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Affiliation(s)
- Maruša Novak
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Urška Čepin
- BioSistemika Ltd and National Institute of Biology, Ljubljana, Slovenia
| | - Vesna Hodnik
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Mojca Narat
- Department of Animal Science, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Maja Jamnik
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Ljubljana, Slovenia
| | - Nada Kraševec
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Ljubljana, Slovenia
| | - Kristina Sepčić
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Gregor Anderluh
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Ljubljana, Slovenia
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17
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Kozorog M, Sani M, Separovic F, Anderluh G. Listeriolysin O Binding Affects Cholesterol and Phospholipid Acyl Chain Dynamics in Fluid Cholesterol‐Rich Bilayers. Chemistry 2018; 24:14220-14225. [DOI: 10.1002/chem.201802575] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Indexed: 01/26/2023]
Affiliation(s)
- Mirijam Kozorog
- Department of Molecular Biology and NanobiotechnologyNational Institute of Chemistry Hajdrihova 19 1000 Ljubljana Slovenia
| | - Marc‐Antoine Sani
- School of ChemistryBio21 InstituteThe University of Melbourne VIC 3010 Australia
| | - Frances Separovic
- School of ChemistryBio21 InstituteThe University of Melbourne VIC 3010 Australia
| | - Gregor Anderluh
- Department of Molecular Biology and NanobiotechnologyNational Institute of Chemistry Hajdrihova 19 1000 Ljubljana Slovenia
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18
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Vezočnik V, Hodnik V, Sitar S, Okur HI, Tušek-Žnidarič M, Lütgebaucks C, Sepčić K, Kogej K, Roke S, Žagar E, Maček P. Kinetically Stable Triglyceride-Based Nanodroplets and Their Interactions with Lipid-Specific Proteins. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:8983-8993. [PMID: 29983071 DOI: 10.1021/acs.langmuir.8b02180] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Understanding of the interactions between proteins and natural and artificially prepared lipid membrane surfaces and embedded nonpolar cores is important in studies of physiological processes and their pathologies and is applicable to nanotechnologies. In particular, rapidly growing interest in cellular droplets defines the need for simplified biomimetic lipid model systems to overcome in vivo complexity and variability. We present a protocol for the preparation of kinetically stable nanoemulsions with nanodroplets composed of sphingomyelin (SM) and cholesterol (Chol), as amphiphilic surfactants, and trioleoylglycerol (TOG), at various molar ratios. To prepare stable SM/Chol-coated monodisperse lipid nanodroplets, we modified a reverse phase evaporation method and combined it with ultrasonication. Lipid composition, ζ-potential, gyration and hydrodynamic radius, shape, and temporal stability of the lipid nanodroplets were characterized and compared to extruded SM/Chol large unilamellar vesicles. Lipid nanodroplets and large unilamellar vesicles with theoretical SM/Chol/TOG molar ratios of 1/1/4.7 and 4/1/11.7 were further investigated for the orientational order of their interfacial water molecules using a second harmonic scattering technique, and for interactions with the SM-binding and Chol-binding pore-forming toxins equinatoxin II and perfringolysin O, respectively. The surface characteristics (ζ-potential, orientational order of interfacial water molecules) and binding of these proteins to the nanodroplet SM/Chol monolayers were similar to those for the SM/Chol bilayers of the large unilamellar vesicles and SM/Chol Langmuir monolayers, in terms of their surface structures. We propose that such SM/Chol/TOG nanoparticles with the required lipid compositions can serve as experimental models for monolayer membrane to provide a system that imitates the natural lipid droplets.
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Affiliation(s)
- Valerija Vezočnik
- Department of Biology, Biotechnical Faculty , University of Ljubljana , Jamnikarjeva 101 , Ljubljana 1000 , Slovenia
| | - Vesna Hodnik
- Department of Biology, Biotechnical Faculty , University of Ljubljana , Jamnikarjeva 101 , Ljubljana 1000 , Slovenia
| | - Simona Sitar
- Department of Polymer Chemistry and Technology , National Institute of Chemistry , Hajdrihova 19 , Ljubljana 1000 , Slovenia
| | - Halil I Okur
- Laboratory for Fundamental BioPhotonics, Institute of Bio-Engineering, and Institute of Material Science, School of Engineering, and Lausanne Centre for Ultrafast Science , École Polytechnique Fédérale de Lausanne , CH-1015 Lausanne , Switzerland
| | | | - Cornelis Lütgebaucks
- Laboratory for Fundamental BioPhotonics, Institute of Bio-Engineering, and Institute of Material Science, School of Engineering, and Lausanne Centre for Ultrafast Science , École Polytechnique Fédérale de Lausanne , CH-1015 Lausanne , Switzerland
| | - Kristina Sepčić
- Department of Biology, Biotechnical Faculty , University of Ljubljana , Jamnikarjeva 101 , Ljubljana 1000 , Slovenia
| | - Ksenija Kogej
- Department of Chemistry and Biochemistry, Faculty of Chemistry and Chemical Technology , University of Ljubljana , Večna pot 113 , Ljubljana 1000 , Slovenia
| | - Sylvie Roke
- Laboratory for Fundamental BioPhotonics, Institute of Bio-Engineering, and Institute of Material Science, School of Engineering, and Lausanne Centre for Ultrafast Science , École Polytechnique Fédérale de Lausanne , CH-1015 Lausanne , Switzerland
| | - Ema Žagar
- Department of Polymer Chemistry and Technology , National Institute of Chemistry , Hajdrihova 19 , Ljubljana 1000 , Slovenia
| | - Peter Maček
- Department of Biology, Biotechnical Faculty , University of Ljubljana , Jamnikarjeva 101 , Ljubljana 1000 , Slovenia
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19
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Molecular mechanisms of action of sphingomyelin-specific pore-forming toxin, lysenin. Semin Cell Dev Biol 2018; 73:188-198. [DOI: 10.1016/j.semcdb.2017.07.036] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 07/18/2017] [Accepted: 07/19/2017] [Indexed: 11/21/2022]
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20
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Desikan R, Maiti PK, Ayappa KG. Assessing the Structure and Stability of Transmembrane Oligomeric Intermediates of an α-Helical Toxin. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:11496-11510. [PMID: 28930630 DOI: 10.1021/acs.langmuir.7b02277] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Protein membrane interactions play an important role in our understanding of diverse phenomena ranging from membrane-assisted protein aggregation to oligomerization and folding. Pore-forming toxins (PFTs) are the primary vehicle for infection by several strains of bacteria. These proteins which are expressed in a water-soluble form (monomers) bind to the target membrane and conformationally transform (protomers) and self-assemble to form a multimer transmembrane pore complex through a process of oligomerization. On the basis of the structure of the transmembrane domains, PFTs are broadly classified into β or α toxins. In contrast to β-PFTs, the paucity of available crystal structures coupled with the amphipathic nature of the transmembrane domains has hindered our understanding of α-PFT pore formation. In this article, we use molecular dynamics (MD) simulations to examine the process of pore formation of the bacterial α-PFT, cytolysin A from Escherichia coli (ClyA) in lipid bilayer membranes. Using atomistic MD simulations ranging from 50 to 500 ns, we show that transmembrane oligomeric intermediates or "arcs" form stable proteolipidic complexes consisting of protein arcs with toroidal lipids lining the free edges. By creating initial conditions where the lipids are contained within the arcs, we study the dynamics of spontaneous lipid evacuation and toroidal edge formation. This process occurs on the time scale of tens of nanoseconds, suggesting that once protomers oligomerize, transmembrane arcs are rapidly stabilized to form functional water channels capable of leakage. Using umbrella sampling with a coarse-grained molecular model, we obtain the free energy of insertion of a single protomer into the membrane. A single inserted protomer has a stabilization free energy of -52.9 ± 1.2 kJ/mol and forms a stable transmembrane water channel capable of leakage. Our simulations reveal that arcs are stable and viable intermediates that can occur during the pore-formation pathway for ClyA.
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Affiliation(s)
- Rajat Desikan
- Department of Chemical Engineering, ‡Centre for Condensed Matter Theory, Department of Physics, and §Centre for Biosystems Science and Engineering, Indian Institute of Science , Bengaluru, India 560012
| | - Prabal K Maiti
- Department of Chemical Engineering, ‡Centre for Condensed Matter Theory, Department of Physics, and §Centre for Biosystems Science and Engineering, Indian Institute of Science , Bengaluru, India 560012
| | - K Ganapathy Ayappa
- Department of Chemical Engineering, ‡Centre for Condensed Matter Theory, Department of Physics, and §Centre for Biosystems Science and Engineering, Indian Institute of Science , Bengaluru, India 560012
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21
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Ni T, Gilbert RJC. Repurposing a pore: highly conserved perforin-like proteins with alternative mechanisms. Philos Trans R Soc Lond B Biol Sci 2017; 372:20160212. [PMID: 28630152 PMCID: PMC5483515 DOI: 10.1098/rstb.2016.0212] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/18/2017] [Indexed: 12/02/2022] Open
Abstract
Pore-forming proteins play critical roles in pathogenic attack and immunological defence. The membrane attack complex/perforin (MACPF) group of homologues represents, with cholesterol-dependent cytolysins, the largest family of such proteins. In this review, we begin by describing briefly the structure of MACPF proteins, outlining their common mechanism of pore formation. We subsequently discuss some examples of MACPF proteins likely implicated in pore formation or other membrane-remodelling processes. Finally, we focus on astrotactin and bone morphogenetic protein and retinoic acid-induced neural-specific proteins, highly conserved MACPF family members involved in developmental processes, which have not been well studied to date or observed to form a pore-and which data suggest may act by alternative mechanisms.This article is part of the themed issue 'Membrane pores: from structure and assembly, to medicine and technology'.
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Affiliation(s)
- Tao Ni
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Robert J C Gilbert
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
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22
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Zhao X, Zhou Y, Wang G, Shi D, Zha Y, Yi P, Wang J. Morin Moderates the Biotoxicity of Pneumococcal Pneumolysin by Weakening the Oligomers' Formation. Chem Pharm Bull (Tokyo) 2017; 65:538-544. [PMID: 28566646 DOI: 10.1248/cpb.c16-00999] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Streptococcus pneumoniae (pneumococcus) is an important causative agent of acute invasive and non-invasive infections. Pneumolysin is one of a considerable number of virulence traits produced by pneumococcus that exhibits a variety of biological activities, thus making it a target of small molecule drug development. In this study, we aimed to evaluate the effect of morin, a natural compound that has no antimicrobial activity against S. pneumonia, is a potent neutralizer of pneumolysin-mediated cytotoxicity and genotoxicity by impairing oligomer formation, and possesses the capability of mitigating tissue damage caused by pneumococcus. These findings indicate that morin could be a potent candidate for a novel therapeutic or auxiliary substance to treat infections for which there are inadequate vaccines and that are resistant to traditional antibiotics.
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Affiliation(s)
- Xiaoran Zhao
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University
| | - Yonglin Zhou
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University
| | - Guizhen Wang
- Department of Food Quality and Safety, Jilin University
| | - Dongxue Shi
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University
| | - Yonghong Zha
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University
| | - Pengfei Yi
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University
| | - Jianfeng Wang
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University
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23
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Leung C, Hodel AW, Brennan AJ, Lukoyanova N, Tran S, House CM, Kondos SC, Whisstock JC, Dunstone MA, Trapani JA, Voskoboinik I, Saibil HR, Hoogenboom BW. Real-time visualization of perforin nanopore assembly. NATURE NANOTECHNOLOGY 2017; 12:467-473. [PMID: 28166206 DOI: 10.1038/nnano.2016.303] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 12/29/2016] [Indexed: 06/06/2023]
Abstract
Perforin is a key protein of the vertebrate immune system. Secreted by cytotoxic lymphocytes as soluble monomers, perforin can self-assemble into oligomeric pores of 10-20 nm inner diameter in the membranes of virus-infected and cancerous cells. These large pores facilitate the entry of pro-apoptotic granzymes, thereby rapidly killing the target cell. To elucidate the pathways of perforin pore assembly, we carried out real-time atomic force microscopy and electron microscopy studies. Our experiments reveal that the pore assembly proceeds via a membrane-bound prepore intermediate state, typically consisting of up to approximately eight loosely but irreversibly assembled monomeric subunits. These short oligomers convert to more closely packed membrane nanopore assemblies, which can subsequently recruit additional prepore oligomers to grow the pore size.
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Affiliation(s)
- Carl Leung
- London Centre for Nanotechnology, University College London, London WC1H 0AH, UK
- Department of Crystallography/Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck College, London WC1E 7HX, UK
| | - Adrian W Hodel
- London Centre for Nanotechnology, University College London, London WC1H 0AH, UK
- Institute of Structural and Molecular Biology, University College London, London WC1E 6BT, UK
| | - Amelia J Brennan
- Killer Cell Biology Laboratory, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3000, Australia
| | - Natalya Lukoyanova
- Department of Crystallography/Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck College, London WC1E 7HX, UK
| | - Sharon Tran
- Killer Cell Biology Laboratory, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3000, Australia
| | - Colin M House
- Cancer Cell Death Laboratory, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3000, Australia
| | - Stephanie C Kondos
- Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Victoria 3800, Australia
| | - James C Whisstock
- Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Victoria 3800, Australia
- The ARC Centre of Excellence in Advanced Molecular Imaging, Monash University, Melbourne, Victoria 3800, Australia
| | - Michelle A Dunstone
- Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Victoria 3800, Australia
- The ARC Centre of Excellence in Advanced Molecular Imaging, Monash University, Melbourne, Victoria 3800, Australia
- Department of Microbiology, Monash University, Melbourne, Victoria 3800, Australia
| | - Joseph A Trapani
- Cancer Cell Death Laboratory, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3000, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Ilia Voskoboinik
- Killer Cell Biology Laboratory, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3000, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Helen R Saibil
- Department of Crystallography/Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck College, London WC1E 7HX, UK
| | - Bart W Hoogenboom
- London Centre for Nanotechnology, University College London, London WC1H 0AH, UK
- Institute of Structural and Molecular Biology, University College London, London WC1E 6BT, UK
- Department of Physics and Astronomy, University College London, London WC1E 6BT, UK
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24
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Intrinsic repair protects cells from pore-forming toxins by microvesicle shedding. Cell Death Differ 2017; 24:798-808. [PMID: 28186501 DOI: 10.1038/cdd.2017.11] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 12/13/2016] [Accepted: 01/17/2017] [Indexed: 01/01/2023] Open
Abstract
Pore-forming toxins (PFTs) are used by both the immune system and by pathogens to disrupt cell membranes. Cells attempt to repair this disruption in various ways, but the exact mechanism(s) that cells use are not fully understood, nor agreed upon. Current models for membrane repair include (1) patch formation (e.g., fusion of internal vesicles with plasma membrane defects), (2) endocytosis of the pores, and (3) shedding of the pores by blebbing from the cell membrane. In this study, we sought to determine the specific mechanism(s) that cells use to resist three different cholesterol-dependent PFTs: Streptolysin O, Perfringolysin O, and Intermedilysin. We found that all three toxins were shed from cells by blebbing from the cell membrane on extracellular microvesicles (MVs). Unique among the cells studied, we found that macrophages were 10 times more resistant to the toxins, yet they shed significantly smaller vesicles than the other cells. To examine the mechanism of shedding, we tested whether toxins with engineered defects in pore formation or oligomerization were shed. We found that oligomerization was necessary and sufficient for membrane shedding, suggesting that calcium influx and patch formation were not required for shedding. However, pore formation enhanced shedding, suggesting that calcium influx and patch formation enhance repair. In contrast, monomeric toxins were endocytosed. These data indicate that cells use two interrelated mechanisms of membrane repair: lipid-dependent MV shedding, which we term 'intrinsic repair', and patch formation by intracellular organelles. Endocytosis may act after membrane repair is complete by removing inactivated and monomeric toxins from the cell surface.
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25
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Fukunaga S, Sogame M, Hata M, Singkaravanit-Ogawa S, Piślewska-Bednarek M, Onozawa-Komori M, Nishiuchi T, Hiruma K, Saitoh H, Terauchi R, Kitakura S, Inoue Y, Bednarek P, Schulze-Lefert P, Takano Y. Dysfunction of Arabidopsis MACPF domain protein activates programmed cell death via tryptophan metabolism in MAMP-triggered immunity. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 89:381-393. [PMID: 27711985 DOI: 10.1111/tpj.13391] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 09/30/2016] [Accepted: 10/03/2016] [Indexed: 05/20/2023]
Abstract
Plant immune responses triggered upon recognition of microbe-associated molecular patterns (MAMPs) typically restrict pathogen growth without a host cell death response. We isolated two Arabidopsis mutants, derived from accession Col-0, that activated cell death upon inoculation with nonadapted fungal pathogens. Notably, the mutants triggered cell death also when treated with bacterial MAMPs such as flg22. Positional cloning identified NSL1 (Necrotic Spotted Lesion 1) as a responsible gene for the phenotype of the two mutants, whereas nsl1 mutations of the accession No-0 resulted in necrotic lesion formation without pathogen inoculation. NSL1 encodes a protein of unknown function containing a putative membrane-attack complex/perforin (MACPF) domain. The application of flg22 increased salicylic acid (SA) accumulation in the nsl1 plants derived from Col-0, while depletion of isochorismate synthase 1 repressed flg22-inducible lesion formation, indicating that elevated SA is needed for the cell death response. nsl1 plants of Col-0 responded to flg22 treatment with an RBOHD-dependent oxidative burst, but this response was dispensable for the nsl1-dependent cell death. Surprisingly, loss-of-function mutations in PEN2, involved in the metabolism of tryptophan (Trp)-derived indole glucosinolates, suppressed the flg22-induced and nsl1-dependent cell death. Moreover, the increased accumulation of SA in the nsl1 plants was abrogated by blocking Trp-derived secondary metabolite biosynthesis, whereas the nsl1-dependent hyperaccumulation of PEN2-dependent compounds was unaffected when the SA biosynthesis pathway was blocked. Collectively, these findings suggest that MAMP-triggered immunity activates a genetically programmed cell death in the absence of the functional MACPF domain protein NSL1 via Trp-derived secondary metabolite-mediated activation of the SA pathway.
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Affiliation(s)
| | - Miho Sogame
- Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Masaki Hata
- Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | | | | | | | - Takumi Nishiuchi
- Advanced Science Research Center, Kanazawa University, Kanazawa, Japan
| | - Kei Hiruma
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Japan
| | | | | | - Saeko Kitakura
- Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Yoshihiro Inoue
- Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Paweł Bednarek
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland
| | - Paul Schulze-Lefert
- Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne, Germany
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26
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Abe Y, Inoue H, Ashida H, Maeda Y, Kinoshita T, Kitada S. Glycan region of GPI anchored-protein is required for cytocidal oligomerization of an anticancer parasporin-2, Cry46Aa1 protein, from Bacillus thuringiensis strain A1547. J Invertebr Pathol 2016; 142:71-81. [PMID: 27863961 DOI: 10.1016/j.jip.2016.11.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Revised: 11/04/2016] [Accepted: 11/14/2016] [Indexed: 11/25/2022]
Abstract
Parasporin-2 (PS2), alternatively named Cry46Aa1, an anticancer protein derived from Bacillus thuringiensis strain A1547, causes specific cell damage via PS2 oligomerization in the cell membrane. Although PS2 requires glycosylphosphatidylinositol (GPI)-anchored proteins for its cytocidal action, their precise role is unknown. Here, we report that the glycan of GPI induces PS2 oligomerization, which causes cell death. Cytotoxicity, cell-binding and oligomerization of the toxin were not observed in GPI-anchored protein-deficient Chinese hamster ovary cells. Expression and protease-treatment analyses showed that the actions of the toxin were dependent on the glycan core, not the polypeptide moiety, of GPI-anchored proteins. However, surface expression of some GPI-anchored proteins is observed in PS2-insensitive cells. These data suggest that GPI-anchored proteins do not determine the target specificity, but instead function as a kind of coreceptor, in the cytocidal action of PS2.
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Affiliation(s)
- Yuich Abe
- Department of Chemistry, Faculty of Science, Kyushu University, Fukuoka 812-8581, Japan
| | - Hiroshi Inoue
- Department of Chemistry, Faculty of Science, Kyushu University, Fukuoka 812-8581, Japan
| | - Hisashi Ashida
- Department of Immunoregulation, Research Institute for Microbial Diseases, Osaka University, Osaka, Osaka 565-0871, Japan
| | - Yusuke Maeda
- Department of Immunoregulation, Research Institute for Microbial Diseases, Osaka University, Osaka, Osaka 565-0871, Japan
| | - Taroh Kinoshita
- Department of Immunoregulation, Research Institute for Microbial Diseases, Osaka University, Osaka, Osaka 565-0871, Japan
| | - Sakae Kitada
- Department of Chemistry, Faculty of Science, Kyushu University, Fukuoka 812-8581, Japan; Department of Bioscience and Bioinformatics, Kyushu Institute of Technology, Iizuka, Fukuoka 820-8502, Japan.
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27
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Lee AA, Senior MJ, Wallace MI, Woolley TE, Griffiths IM. Dissecting the self-assembly kinetics of multimeric pore-forming toxins. J R Soc Interface 2016; 13:20150762. [PMID: 26763328 DOI: 10.1098/rsif.2015.0762] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Pore-forming toxins are ubiquitous cytotoxins that are exploited by both bacteria and the immune response of eukaryotes. These toxins kill cells by assembling large multimeric pores on the cell membrane. However, a quantitative understanding of the mechanism and kinetics of this self-assembly process is lacking. We propose an analytically solvable kinetic model for stepwise, reversible oligomerization. In biologically relevant limits, we obtain simple algebraic expressions for the rate of pore formation, as well as for the concentration of pores as a function of time. Quantitative agreement is obtained between our model and time-resolved kinetic experiments of Bacillus thuringiensis Cry1Ac (tetrameric pore), aerolysin, Staphylococcus aureus α-haemolysin (heptameric pores) and Escherichia coli cytolysin A (dodecameric pore). Furthermore, our model explains how rapid self-assembly can take place with low concentrations of oligomeric intermediates, as observed in recent single-molecule fluorescence experiments of α-haemolysin self-assembly. We propose that suppressing the concentration of oligomeric intermediates may be the key to reliable, error-free, self-assembly of pores.
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Affiliation(s)
- A A Lee
- Mathematical Institute, University of Oxford, Radcliffe Observatory Quarter, Woodstock Road, Oxford, Oxfordshire, UK School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 01238, USA
| | - M J Senior
- Physical and Theoretical Chemistry, South Parks Road, Oxford OX1 3QZ
| | - M I Wallace
- Physical and Theoretical Chemistry, South Parks Road, Oxford OX1 3QZ
| | - T E Woolley
- Mathematical Institute, University of Oxford, Radcliffe Observatory Quarter, Woodstock Road, Oxford, Oxfordshire, UK
| | - I M Griffiths
- Mathematical Institute, University of Oxford, Radcliffe Observatory Quarter, Woodstock Road, Oxford, Oxfordshire, UK
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28
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Hodel AW, Leung C, Dudkina NV, Saibil HR, Hoogenboom BW. Atomic force microscopy of membrane pore formation by cholesterol dependent cytolysins. Curr Opin Struct Biol 2016; 39:8-15. [DOI: 10.1016/j.sbi.2016.03.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 03/08/2016] [Accepted: 03/14/2016] [Indexed: 11/16/2022]
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29
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Tenenbaum T, Asmat TM, Seitz M, Schroten H, Schwerk C. Biological activities of suilysin: role in Streptococcus suis pathogenesis. Future Microbiol 2016; 11:941-54. [PMID: 27357518 DOI: 10.2217/fmb-2016-0028] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Streptococcus suis is an important swine and zoonotic pathogen equipped with several virulence factors. The pore-forming toxins are the most abundant bacterial toxins and classified as critical virulence (associated) factors of several pathogens. The role of suilysin (SLY), a pore-forming cholesterol-dependent cytolysin of S. suis, as a true virulence factor is under debate. Most of the bacterial toxins have been reported to modulate the host immune system to facilitate invasion and subsequent replication of bacteria within respective host cells. SLY has been demonstrated to play an important role in the pathogenesis of S. suis infection and inflammatory response in vitro and in vivo. This review highlights the contributions of SLY to the pathogenicity of S. suis. It will address its role during the development of S. suis meningitis in pigs, as well as humans, and discuss SLY as a potential vaccine candidate.
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Affiliation(s)
- Tobias Tenenbaum
- Pediatric Infectious Diseases, Department of Pediatrics, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, Mannheim D-68167, Germany
| | - Tauseef M Asmat
- Center for Advanced Studies in Vaccinology and Biotechnology, Brewery Road, University of Balochistan, 87300 Quetta, Pakistan
| | - Maren Seitz
- Institute for Microbiology, University of Veterinary Medicine Hannover, Bischofsholer Damm 15, Hannover D-30173, Germany
| | - Horst Schroten
- Pediatric Infectious Diseases, Department of Pediatrics, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, Mannheim D-68167, Germany
| | - Christian Schwerk
- Pediatric Infectious Diseases, Department of Pediatrics, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, Mannheim D-68167, Germany
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30
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Zhang J, Yang Y, He W, Sun L. Necrosome core machinery: MLKL. Cell Mol Life Sci 2016; 73:2153-63. [PMID: 27048809 PMCID: PMC11108342 DOI: 10.1007/s00018-016-2190-5] [Citation(s) in RCA: 119] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 03/18/2016] [Indexed: 12/22/2022]
Abstract
In the study of regulated cell death, the rapidly expanding field of regulated necrosis, in particular necroptosis, has been drawing much attention. The signaling of necroptosis represents a sophisticated form of a death pathway. Anti-caspase mechanisms (e.g., using inhibitors of caspases, or genetic ablation of caspase-8) switch cell fate from apoptosis to necroptosis. The initial extracellular death signals regulate RIP1 and RIP3 kinase activation. The RIP3-associated death complex assembly is necessary and sufficient to initiate necroptosis. MLKL was initially identified as an essential mediator of RIP1/RIP3 kinase-initiated necroptosis. Recent studies on the signal transduction using chemical tools and biomarkers support the idea that MLKL is able to make more functional sense for the core machinery of the necroptosis death complex, called the necrosome, to connect to the necroptosis execution. The experimental data available now have pointed that the activated MLKL forms membrane-disrupting pores causing membrane leakage, which extends the prototypical concept of morphological and biochemical events following necroptosis happening in vivo. The key role of MLKL in necroptosis signaling thus sheds light on the logic underlying this unique "membrane-explosive" cell death pathway. In this review, we provide the general concepts and strategies that underlie signal transduction of this form of cell death, and then focus specifically on the role of MLKL in necroptosis.
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Affiliation(s)
- Jing Zhang
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Rd, Shanghai, 200031, China
| | - Yu Yang
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Rd, Shanghai, 200031, China
| | - Wenyan He
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Rd, Shanghai, 200031, China
| | - Liming Sun
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Rd, Shanghai, 200031, China.
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31
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Ni T, Harlos K, Gilbert R. Structure of astrotactin-2: a conserved vertebrate-specific and perforin-like membrane protein involved in neuronal development. Open Biol 2016; 6:rsob.160053. [PMID: 27249642 PMCID: PMC4892435 DOI: 10.1098/rsob.160053] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 04/07/2016] [Indexed: 11/30/2022] Open
Abstract
The vertebrate-specific proteins astrotactin-1 and 2 (ASTN-1 and ASTN-2) are integral membrane perforin-like proteins known to play critical roles in neurodevelopment, while ASTN-2 has been linked to the planar cell polarity pathway in hair cells. Genetic variations associated with them are linked to a variety of neurodevelopmental disorders and other neurological pathologies, including an advanced onset of Alzheimer's disease. Here we present the structure of the majority endosomal region of ASTN-2, showing it to consist of a unique combination of polypeptide folds: a perforin-like domain, a minimal epidermal growth factor-like module, a unique form of fibronectin type III domain and an annexin-like domain. The perforin-like domain differs from that of other members of the membrane attack complex-perforin (MACPF) protein family in ways that suggest ASTN-2 does not form pores. Structural and biophysical data show that ASTN-2 (but not ASTN-1) binds inositol triphosphates, suggesting a mechanism for membrane recognition or secondary messenger regulation of its activity. The annexin-like domain is closest in fold to repeat three of human annexin V and similarly binds calcium, and yet shares no sequence homology with it. Overall, our structure provides the first atomic-resolution description of a MACPF protein involved in development, while highlighting distinctive features of ASTN-2 responsible for its activity.
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Affiliation(s)
- Tao Ni
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Karl Harlos
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Robert Gilbert
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
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32
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Ruan Y, Rezelj S, Bedina Zavec A, Anderluh G, Scheuring S. Listeriolysin O Membrane Damaging Activity Involves Arc Formation and Lineaction -- Implication for Listeria monocytogenes Escape from Phagocytic Vacuole. PLoS Pathog 2016; 12:e1005597. [PMID: 27104344 PMCID: PMC4841516 DOI: 10.1371/journal.ppat.1005597] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 04/04/2016] [Indexed: 12/15/2022] Open
Abstract
Listeriolysin-O (LLO) plays a crucial role during infection by Listeria monocytogenes. It enables escape of bacteria from phagocytic vacuole, which is the basis for its spread to other cells and tissues. It is not clear how LLO acts at phagosomal membranes to allow bacterial escape. The mechanism of action of LLO remains poorly understood, probably due to unavailability of suitable experimental tools that could monitor LLO membrane disruptive activity in real time. Here, we used high-speed atomic force microscopy (HS-AFM) featuring high spatio-temporal resolution on model membranes and optical microscopy on giant unilamellar vesicles (GUVs) to investigate LLO activity. We analyze the assembly kinetics of toxin oligomers, the prepore-to-pore transition dynamics and the membrane disruption in real time. We reveal that LLO toxin efficiency and mode of action as a membrane-disrupting agent varies strongly depending on the membrane cholesterol concentration and the environmental pH. We discovered that LLO is able to form arc pores as well as damage lipid membranes as a lineactant, and this leads to large-scale membrane defects. These results altogether provide a mechanistic basis of how large-scale membrane disruption leads to release of Listeria from the phagocytic vacuole in the cellular context.
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Affiliation(s)
- Yi Ruan
- U1006 INSERM, Université Aix-Marseille, Parc Scientifique et Technologique de Luminy, Marseille, France
| | - Saša Rezelj
- Department for Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Ljubljana, Slovenia
| | - Apolonija Bedina Zavec
- Department for Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Ljubljana, Slovenia
| | - Gregor Anderluh
- Department for Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Ljubljana, Slovenia
- * E-mail: (SS); (GA)
| | - Simon Scheuring
- U1006 INSERM, Université Aix-Marseille, Parc Scientifique et Technologique de Luminy, Marseille, France
- * E-mail: (SS); (GA)
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33
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Gilbert RJC, Sonnen AFP. Measuring kinetic drivers of pneumolysin pore structure. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2016; 45:365-76. [PMID: 26906727 PMCID: PMC4823331 DOI: 10.1007/s00249-015-1106-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Revised: 12/01/2015] [Accepted: 12/07/2015] [Indexed: 11/03/2022]
Abstract
Most membrane attack complex-perforin/cholesterol-dependent cytolysin (MACPF/CDC) proteins are thought to form pores in target membranes by assembling into pre-pore oligomers before undergoing a pre-pore to pore transition. Assembly during pore formation is into both full rings of subunits and incomplete rings (arcs). The balance between arcs and full rings is determined by a mechanism dependent on protein concentration in which arc pores arise due to kinetic trapping of the pre-pore forms by the depletion of free protein subunits during oligomerization. Here we describe the use of a kinetic assay to study pore formation in red blood cells by the MACPF/CDC pneumolysin from Streptococcus pneumoniae. We show that cell lysis displays two kinds of dependence on protein concentration. At lower concentrations, it is dependent on the pre-pore to pore transition of arc oligomers, which we show to be a cooperative process. At higher concentrations, it is dependent on the amount of pneumolysin bound to the membrane and reflects the affinity of the protein for its receptor, cholesterol. A lag occurs before cell lysis begins; this is dependent on oligomerization of pneumolysin. Kinetic dissection of cell lysis by pneumolysin demonstrates the capacity of MACPF/CDCs to generate pore-forming oligomeric structures of variable size with, most likely, different functional roles in biology.
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Affiliation(s)
- Robert J C Gilbert
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, OX3 7BN, UK.
| | - Andreas F-P Sonnen
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, Meyerhofstraße 1, 69117, Heidelberg, Germany
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34
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Lukoyanova N, Hoogenboom BW, Saibil HR. The membrane attack complex, perforin and cholesterol-dependent cytolysin superfamily of pore-forming proteins. J Cell Sci 2016; 129:2125-33. [DOI: 10.1242/jcs.182741] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
ABSTRACT
The membrane attack complex and perforin proteins (MACPFs) and bacterial cholesterol-dependent cytolysins (CDCs) are two branches of a large and diverse superfamily of pore-forming proteins that function in immunity and pathogenesis. During pore formation, soluble monomers assemble into large transmembrane pores through conformational transitions that involve extrusion and refolding of two α-helical regions into transmembrane β-hairpins. These transitions entail a dramatic refolding of the protein structure, and the resulting assemblies create large holes in cellular membranes, but they do not use any external source of energy. Structures of the membrane-bound assemblies are required to mechanistically understand and modulate these processes. In this Commentary, we discuss recent advances in the understanding of assembly mechanisms and molecular details of the conformational changes that occur during MACPF and CDC pore formation.
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Affiliation(s)
- Natalya Lukoyanova
- Department of Crystallography/Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck College, London WC1E 7HX, UK
| | - Bart W. Hoogenboom
- London Centre for Nanotechnology, University College London, London WC1H 0AH, UK
- Department of Physics and Astronomy, University College London, London WC1E 6BT, UK
| | - Helen R. Saibil
- Department of Crystallography/Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck College, London WC1E 7HX, UK
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35
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Abstract
Pore forming toxins (PFTs) evolved to permeate the plasma membrane of target cells. This is achieved in a multistep mechanism that usually involves binding of soluble protein monomer to the lipid membrane, oligomerization at the plane of the membrane, and insertion of part of the polypeptide chain across the lipid membrane to form a conductive channel. Introduced pores allow uncontrolled transport of solutes across the membrane, inflicting damage to the target cell. PFTs are usually studied from the perspective of structure-function relationships, often neglecting the important role of the bulk membrane properties on the PFT mechanism of action. In this Account, we discuss how membrane lateral heterogeneity, thickness, and fluidity influence the pore forming process of PFTs. In general, lipid molecules are more accessible for binding in fluid membranes due to steric reasons. When PFT specifically binds ordered domains, it usually recognizes a specific lipid distribution pattern, like sphingomyelin (SM) clusters or SM/cholesterol complexes, and not individual lipid species. Lipid domains were also suggested to act as an additional concentration platform facilitating PFT oligomerization, but this is yet to be shown. The last stage in PFT action is the insertion of the transmembrane segment across the membranes to build the transmembrane pore walls. Conformational changes are a spontaneous process, and sufficient free energy has to be available for efficient membrane penetration. Therefore, fluid bilayers are permeabilized more readily in comparison to highly ordered and thicker liquid ordered lipid phase (Lo). Energetically more costly insertion into the Lo phase can be driven by the hydrophobic mismatch between the thinner liquid disordered phase (Ld) and large protein complexes, which are unable to tilt like single transmembrane segments. In the case of proteolipid pores, membrane properties can directly modulate pore size, stability, and even selectivity. Finally, events associated with pore formation can modulate properties of the lipid membrane and affect its organization. Model membranes do not necessarily reproduce the physicochemical properties of the native cellular membrane, and caution is needed when transferring results from model to native lipid membranes. In this context, the utilization of novel approaches that enable studying PFTs on living cells at a single molecule level should reveal complex protein-lipid membrane interactions in greater detail.
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Affiliation(s)
- Nejc Rojko
- Laboratory
for Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
| | - Gregor Anderluh
- Laboratory
for Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
- Department
of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva
101, 1000 Ljubljana, Slovenia
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36
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Gilbert RJC. Protein-lipid interactions and non-lamellar lipidic structures in membrane pore formation and membrane fusion. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1858:487-99. [PMID: 26654785 DOI: 10.1016/j.bbamem.2015.11.026] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2015] [Revised: 10/23/2015] [Accepted: 11/30/2015] [Indexed: 12/27/2022]
Abstract
Pore-forming proteins and peptides act on their targeted lipid bilayer membranes to increase permeability. This approach to the modulation of biological function is relevant to a great number of living processes, including; infection, parasitism, immunity, apoptosis, development and neurodegeneration. While some pore-forming proteins/peptides assemble into rings of subunits to generate discrete, well-defined pore-forming structures, an increasing number is recognised to form pores via mechanisms which co-opt membrane lipids themselves. Among these, membrane attack complex-perforin/cholesterol-dependent cytolysin (MACPF/CDC) family proteins, Bax/colicin family proteins and actinoporins are especially prominent and among the mechanisms believed to apply are the formation of non-lamellar (semi-toroidal or toroidal) lipidic structures. In this review I focus on the ways in which lipids contribute to pore formation and contrast this with the ways in which lipids are co-opted also in membrane fusion and fission events. A variety of mechanisms for pore formation that involve lipids exists, but they consistently result in stable hybrid proteolipidic structures. These structures are stabilised by mechanisms in which pore-forming proteins modify the innate capacity of lipid membranes to respond to their environment, changing shape and/or phase and binding individual lipid molecules directly. In contrast, and despite the diversity in fusion protein types, mechanisms for membrane fusion are rather similar to each other, mapping out a pathway from pairs of separated compartments to fully confluent fused membranes. Fusion proteins generate metastable structures along the way which, like long-lived proteolipidic pore-forming complexes, rely on the basic physical properties of lipid bilayers. Membrane fission involves similar intermediates, in the reverse order. I conclude by considering the possibility that at least some pore-forming and fusion proteins are evolutionarily related homologues. This article is part of a Special Issue entitled: Pore-Forming Toxins edited by Mauro Dalla Serra and Franco Gambale.
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Affiliation(s)
- Robert J C Gilbert
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK.
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Assemblies of pore-forming toxins visualized by atomic force microscopy. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1858:500-11. [PMID: 26577274 DOI: 10.1016/j.bbamem.2015.11.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2015] [Revised: 10/23/2015] [Accepted: 11/09/2015] [Indexed: 02/05/2023]
Abstract
A number of pore-forming toxins (PFTs) can assemble on lipid membranes through their specific interactions with lipids. The oligomeric assemblies of some PFTs have been successfully revealed either by electron microscopy (EM) and/or atomic force microscopy (AFM). Unlike EM, AFM imaging can be performed under physiological conditions, enabling the real-time visualization of PFT assembly and the transition from the prepore state, in which the toxin does not span the membrane, to the pore state. In addition to characterizing PFT oligomers, AFM has also been used to examine toxin-induced alterations in membrane organization. In this review, we summarize the contributions of AFM to the understanding of both PFT assembly and PFT-induced membrane reorganization. This article is part of a Special Issue entitled: Pore-Forming Toxins edited by Mauro Dalla Serra and Franco Gambale.
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He J, Wang J, Hu J, Sun J, Czajkowsky DM, Shao Z. Single molecule atomic force microscopy of aerolysin pore complexes reveals unexpected star-shaped topography. J Mol Recognit 2015; 29:174-81. [PMID: 26537438 DOI: 10.1002/jmr.2517] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 10/11/2015] [Accepted: 10/11/2015] [Indexed: 12/16/2022]
Abstract
Aerolysin is the paradigmatic member of a large family of toxins that convert from a water-soluble monomer/dimer into a membrane-spanning oligomeric pore. While there is x-ray crystallographic data of its water-soluble conformation, the most recent structural model of the membrane-inserted pore is based primarily on data of water-soluble tetradecamers of mutant protein, together with computational modeling ultimately performed in vacuum. Here we examine this pore model with atomic force microscopy (AFM) of membrane-associated wild-type complexes and all-atom molecular dynamics (MD) simulations in water. In striking contrast to a disc-shaped cap region predicted by the present model, the AFM images reveal a star-shaped complex, with a central ring surrounded by seven radial projections. Further, the MD simulations suggest that the locations of the receptor-binding (D1) domains in the present model are not correct. However, a modified model in which the D1 domains, rather than localized at fixed positions, adopt a wide range of configurations through fluctuations of an intervening linker is compatible with existing data. Thus our work not only demonstrates the importance of directly resolving such complexes in their native environment but also points to a dynamic receptor binding region, which may be critical for toxin assembly on the cell surface.
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Affiliation(s)
- Jianfeng He
- Bio-ID Center, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Jiabin Wang
- Key Laboratory of Systems Biomedicine, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Jun Hu
- Division of Physical Biology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, 201800, China
| | - Jielin Sun
- Bio-ID Center, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.,Key Laboratory of Systems Biomedicine, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Daniel Mark Czajkowsky
- Bio-ID Center, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Zhifeng Shao
- Bio-ID Center, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
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Naneh O, Zavec AB, Pahovnik D, Žagar E, Gilbert RJ, Križaj I, Anderluh G. An optimized protocol for expression and purification of murine perforin in insect cells. J Immunol Methods 2015. [DOI: 10.1016/j.jim.2015.07.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Rojko N, Dalla Serra M, Maček P, Anderluh G. Pore formation by actinoporins, cytolysins from sea anemones. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1858:446-56. [PMID: 26351738 DOI: 10.1016/j.bbamem.2015.09.007] [Citation(s) in RCA: 91] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 08/31/2015] [Accepted: 09/02/2015] [Indexed: 11/30/2022]
Abstract
Actinoporins (APs) from sea anemones are ~20 kDa pore forming toxins with a β-sandwich structure flanked by two α-helices. The molecular mechanism of APs pore formation is composed of several well-defined steps. APs bind to membrane by interfacial binding site composed of several aromatic amino acid residues that allow binding to phosphatidylcholine and specific recognition of sphingomyelin. Subsequently, the N-terminal α-helix from the β-sandwich has to be inserted into the lipid/water interphase in order to form a functional pore. Functional studies and single molecule imaging revealed that only several monomers, 3-4, oligomerise to form a functional pore. In this model the α-helices and surrounding lipid molecules build toroidal pore. In agreement, AP pores are transient and electrically heterogeneous. On the contrary, crystallized oligomers of actinoporin fragaceatoxin C were found to be composed of eight monomers with no lipids present between the adjacent α-helices. This article is part of a Special Issue entitled: Pore-Forming Toxins edited by Maur Dalla Serra and Franco Gambale.
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Affiliation(s)
- Nejc Rojko
- Laboratory for Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
| | - Mauro Dalla Serra
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche & Fondazione Bruno Kessler, via alla Cascata 56/C, 38123 Trento, Italy
| | - Peter Maček
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000 Ljubljana, Slovenia
| | - Gregor Anderluh
- Laboratory for Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia; Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000 Ljubljana, Slovenia.
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41
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Podobnik M, Marchioretto M, Zanetti M, Bavdek A, Kisovec M, Cajnko MM, Lunelli L, Dalla Serra M, Anderluh G. Plasticity of listeriolysin O pores and its regulation by pH and unique histidine [corrected]. Sci Rep 2015; 5:9623. [PMID: 25854672 PMCID: PMC5381700 DOI: 10.1038/srep09623] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 03/12/2015] [Indexed: 12/12/2022] Open
Abstract
Pore formation of cellular membranes is an ancient mechanism of bacterial pathogenesis that allows efficient damaging of target cells. Several mechanisms have been described, however, relatively little is known about the assembly and properties of pores. Listeriolysin O (LLO) is a pH-regulated cholesterol-dependent cytolysin from the intracellular pathogen Listeria monocytogenes, which forms transmembrane β-barrel pores. Here we report that the assembly of LLO pores is rapid and efficient irrespective of pH. While pore diameters at the membrane surface are comparable at either pH 5.5 or 7.4, the distribution of pore conductances is significantly pH-dependent. This is directed by the unique residue H311, which is also important for the conformational stability of the LLO monomer and the rate of pore formation. The functional pores exhibit variations in height profiles and can reconfigure significantly by merging to other full pores or arcs. Our results indicate significant plasticity of large β-barrel pores, controlled by environmental cues like pH.
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Affiliation(s)
- Marjetka Podobnik
- Laboratory for Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
| | - Marta Marchioretto
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche &Fondazione Bruno Kessler, via alla Cascata 56/C, 38123 Trento, Italy
| | - Manuela Zanetti
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche &Fondazione Bruno Kessler, via alla Cascata 56/C, 38123 Trento, Italy
| | - Andrej Bavdek
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, 1000 Ljubljana, Slovenia
| | - Matic Kisovec
- Laboratory for Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
| | - Miša Mojca Cajnko
- Laboratory for Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
| | - Lorenzo Lunelli
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche &Fondazione Bruno Kessler, via alla Cascata 56/C, 38123 Trento, Italy
| | - Mauro Dalla Serra
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche &Fondazione Bruno Kessler, via alla Cascata 56/C, 38123 Trento, Italy
| | - Gregor Anderluh
- 1] Laboratory for Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia [2] Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, 1000 Ljubljana, Slovenia
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42
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Vrecl M, Babnik M, Diacci U, Benoit E, Frangež R. Effect of the ostreolysin A/pleurotolysin B pore-forming complex on neuroblastoma cell morphology and intracellular Ca²⁺ activity. Toxicol Sci 2015; 144:276-83. [PMID: 25556216 DOI: 10.1093/toxsci/kfu316] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Ostreolysin A (OlyA) and pleurotolysin B (PlyB), isolated from edible oyster mushrooms, form a cytolytic complex (OlyA/PlyB) in membrane cells that causes respiratory arrest. This study evaluated the mechanisms underlying cytotoxic OlyA/PlyB activity in neuroblastoma NG108-15 cells. Confocal microscopy with morphometric analysis revealed that OlyA/PlyB increased the 3-dimensional projected area of differentiated cells. Iso-osmotic replacement of NaCl by sucrose or Na-isethionate prevented the cellular swelling. This suggests that formation of cellular edema requires the presence of Na(+) and/or Cl(-) in the extracellular space and may be related to an influx of Na(+) and/or a shift in Cl(-), which induce a marked influx of water that is ultimately responsible for cellular swelling. In addition, extracellular Ca(2+) moderately contributed to the swelling because benzamil (10 µM), a 3Na(+)/Ca(2+) exchange (NCX) inhibitor, and Ca(2+)-free medium partially prevented this response. Fluorometric measurements revealed that OlyA/PlyB, at approximately 15-fold higher concentrations, increased the intracellular Ca(2+) activity [Ca(2+)]i. This increase was dependent on the presence of Na(+) and Ca(2+) in the external medium and was sensitive to benzamil. It is thus likely that a switch in the NCX mode, associated with the de novo formation of non-selective ion pores by OlyA/PlyB in cellular plasma membranes, plays an important role in this effect. Overall, OlyA/PlyB affects neuroblastoma cell morphology and Ca(2+) homeostasis to influence the toxin-induced respiratory arrest.
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Affiliation(s)
- Milka Vrecl
- *Veterinary Faculty, Institute of Anatomy, Histology and Embryology, Veterinary Faculty, Institute of Physiology, Pharmacology and Toxicology, University of Ljubljana, Gerbičeva 60, 1000 Ljubljana, Slovenia and CNRS, Institut de Neurobiologie Alfred Fessard, Laboratoire de Neurobiologie et Développement Bât. 32-33, 91198 Gif sur Yvette cedex, France
| | - Monika Babnik
- *Veterinary Faculty, Institute of Anatomy, Histology and Embryology, Veterinary Faculty, Institute of Physiology, Pharmacology and Toxicology, University of Ljubljana, Gerbičeva 60, 1000 Ljubljana, Slovenia and CNRS, Institut de Neurobiologie Alfred Fessard, Laboratoire de Neurobiologie et Développement Bât. 32-33, 91198 Gif sur Yvette cedex, France
| | - Uroš Diacci
- *Veterinary Faculty, Institute of Anatomy, Histology and Embryology, Veterinary Faculty, Institute of Physiology, Pharmacology and Toxicology, University of Ljubljana, Gerbičeva 60, 1000 Ljubljana, Slovenia and CNRS, Institut de Neurobiologie Alfred Fessard, Laboratoire de Neurobiologie et Développement Bât. 32-33, 91198 Gif sur Yvette cedex, France
| | - Evelyne Benoit
- *Veterinary Faculty, Institute of Anatomy, Histology and Embryology, Veterinary Faculty, Institute of Physiology, Pharmacology and Toxicology, University of Ljubljana, Gerbičeva 60, 1000 Ljubljana, Slovenia and CNRS, Institut de Neurobiologie Alfred Fessard, Laboratoire de Neurobiologie et Développement Bât. 32-33, 91198 Gif sur Yvette cedex, France
| | - Robert Frangež
- *Veterinary Faculty, Institute of Anatomy, Histology and Embryology, Veterinary Faculty, Institute of Physiology, Pharmacology and Toxicology, University of Ljubljana, Gerbičeva 60, 1000 Ljubljana, Slovenia and CNRS, Institut de Neurobiologie Alfred Fessard, Laboratoire de Neurobiologie et Développement Bât. 32-33, 91198 Gif sur Yvette cedex, France
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Novak M, Kraševec N, Skočaj M, Maček P, Anderluh G, Sepčić K. Fungal aegerolysin-like proteins: distribution, activities, and applications. Appl Microbiol Biotechnol 2014; 99:601-10. [PMID: 25476018 DOI: 10.1007/s00253-014-6239-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Revised: 11/13/2014] [Accepted: 11/14/2014] [Indexed: 12/15/2022]
Abstract
The aegerolysin protein family (from aegerolysin of the mushroom Agrocybe aegerita) comprises proteins of ∼15-20 kDa from various eukaryotic and bacterial taxa. Aegerolysins are inconsistently distributed among fungal species, and variable numbers of homologs have been reported for species within the same genus. As such noncore proteins, without a member of a protein family in each of the sequenced fungi, they can give insight into different species-specific processes. Some aegerolysins have been reported to be hemolytically active against mammalian erythrocytes. However, some function as bi-component proteins that have membrane activity in concert with another protein that contains a membrane attack complex/perforin domain. The function of most of aegerolysins is unknown, although some have been suggested to have a role in development of the organism. Potential biotechnological applications of aegerolysins are already evident, despite the limited scientific knowledge available at present. Some mushroom aegerolysins, for example, can be used as markers to detect and label specific membrane lipids. Others can be used as biomarkers of fungal exposure, where their genes can serve as targets for detection of fungi and their progression during infectious diseases. Antibodies against aegerolysins can also be raised as immuno-diagnostic tools. Aegerolysins have been shown to serve as a species determination tool for fungal phytopathogen isolates in terms of some closely related species, where commonly used internal transcribed spacer barcoding has failed. Moreover, strong promoters that regulate aegerolysin genes can promote secretion of heterologous proteins from fungi and have been successfully applied in simultaneous multi-gene expression techniques.
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Affiliation(s)
- Maruša Novak
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, SI-1000, Ljubljana, Slovenia
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44
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Rojko N, Cronin B, Danial JSH, Baker MAB, Anderluh G, Wallace MI. Imaging the lipid-phase-dependent pore formation of equinatoxin II in droplet interface bilayers. Biophys J 2014; 106:1630-7. [PMID: 24739162 DOI: 10.1016/j.bpj.2013.11.4507] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Revised: 09/23/2013] [Accepted: 11/27/2013] [Indexed: 11/17/2022] Open
Abstract
Using phase-separated droplet interface bilayers, we observe membrane binding and pore formation of a eukaryotic cytolysin, Equinatoxin II (EqtII). EqtII activity is known to depend on the presence of sphingomyelin in the target membrane and is enhanced by lipid phase separation. By imaging the ionic flux through individual pores in vitro, we observe that EqtII pores form predominantly within the liquid-disordered phase. We observe preferential binding of labeled EqtII at liquid-ordered/liquid-disordered domain boundaries before it accumulates in the liquid-disordered phase.
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Affiliation(s)
- N Rojko
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - B Cronin
- Department of Chemistry, Oxford University, Oxford, UK
| | - J S H Danial
- Department of Chemistry, Oxford University, Oxford, UK
| | - M A B Baker
- Department of Chemistry, Oxford University, Oxford, UK
| | - G Anderluh
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia; National Institute of Chemistry, Ljubljana, Slovenia.
| | - M I Wallace
- Department of Chemistry, Oxford University, Oxford, UK.
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45
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Clostridial pore-forming toxins: Powerful virulence factors. Anaerobe 2014; 30:220-38. [DOI: 10.1016/j.anaerobe.2014.05.014] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 04/16/2014] [Accepted: 05/25/2014] [Indexed: 01/05/2023]
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46
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Gilbert RJ, Serra MD, Froelich CJ, Wallace MI, Anderluh G. Membrane pore formation at protein–lipid interfaces. Trends Biochem Sci 2014; 39:510-6. [DOI: 10.1016/j.tibs.2014.09.002] [Citation(s) in RCA: 125] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 09/13/2014] [Accepted: 09/15/2014] [Indexed: 11/15/2022]
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47
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Perforin oligomers form arcs in cellular membranes: a locus for intracellular delivery of granzymes. Cell Death Differ 2014; 22:74-85. [PMID: 25146929 DOI: 10.1038/cdd.2014.110] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 07/01/2014] [Accepted: 07/03/2014] [Indexed: 01/28/2023] Open
Abstract
Perforin-mediated cytotoxicity is an essential host defense, in which defects contribute to tumor development and pathogenic disorders including autoimmunity and autoinflammation. How perforin (PFN) facilitates intracellular delivery of pro-apoptotic and inflammatory granzymes across the bilayer of targets remains unresolved. Here we show that cellular susceptibility to granzyme B (GzmB) correlates with rapid PFN-induced phosphatidylserine externalization, suggesting that pores are formed at a protein-lipid interface by incomplete membrane oligomers (or arcs). Supporting a role for these oligomers in protease delivery, an anti-PFN antibody (pf-80) suppresses necrosis but increases phosphatidylserine flip-flop and GzmB-induced apoptosis. As shown by atomic force microscopy on planar bilayers and deep-etch electron microscopy on mammalian cells, pf-80 increases the proportion of arcs which correlates with the presence of smaller electrical conductances, while large cylindrical pores decline. PFN appears to form arc structures on target membranes that serve as minimally disrupting conduits for GzmB translocation. The role of these arcs in PFN-mediated pathology warrants evaluation where they may serve as novel therapeutic targets.
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48
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Duncan EJ, Johnson TK, Whisstock JC, Warr CG, Dearden PK. Capturing embryonic development from metamorphosis: how did the terminal patterning signalling pathway of Drosophila evolve? CURRENT OPINION IN INSECT SCIENCE 2014; 1:45-51. [PMID: 32846729 DOI: 10.1016/j.cois.2014.04.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2014] [Revised: 04/29/2014] [Accepted: 04/29/2014] [Indexed: 06/11/2023]
Abstract
The Torso receptor tyrosine kinase has two crucial roles in Drosophila melanogaster development. One is in the control of insect moulting, which is regulated by the neuropeptide hormone PTTH (prothoracicotropic hormone). PTTH activates ERK signalling via Torso in the prothoracic gland to stimulate ecdysone secretion. Torso also has a role in control of one of the earliest events in embryogenesis in Drosophila; patterning of the embryonic termini. Here Torso is activated by a different, but related, peptide called Trunk. During terminal patterning another protein, Torso-like, has a key role in mediating activation of Torso by Trunk. Torso-like is also expressed in the prothoracic gland and null-mutants have defective developmental timing in Drosophila. This function, however, has been recently shown to be independent of Torso and PTTH. We refer to these proteins, Trunk, PTTH, Torso and Torso-like, as the Torso-activation module. Outside Drosophila we see that the genes encoding the Torso-activation module have a complex phylogenetic history, with different origins and multiple losses of components of this signalling pathway during arthropod evolution. This, together with expression and functional data in a range of insects, leads us to propose that the terminal patterning pathway in Drosophila and Tribolium arose through co-option of PTTH/Trunk and Torso, which has a role in developmental timing, into a new context, and that Torso-like was recruited specifically in the ovary to modulate the specificity of this pathway.
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Affiliation(s)
- Elizabeth J Duncan
- Genetics Otago, University of Otago, P.O. Box 56, Dunedin, Aotearoa, New Zealand; Gravida; The National Centre for Growth and Development, University of Otago, P.O. Box 56, Dunedin, Aotearoa, New Zealand
| | - Travis K Johnson
- School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia; Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC 3800, Australia
| | - James C Whisstock
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC 3800, Australia; Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, VIC 3800, Australia
| | - Coral G Warr
- School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia
| | - Peter K Dearden
- Genetics Otago, University of Otago, P.O. Box 56, Dunedin, Aotearoa, New Zealand; Gravida; The National Centre for Growth and Development, University of Otago, P.O. Box 56, Dunedin, Aotearoa, New Zealand.
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Abstract
Pneumolysin is a member of the cholesterol-dependent cytolysin (CDC) family of pore-forming proteins that are produced as water-soluble monomers or dimers, bind to target membranes and oligomerize into large ring-shaped assemblies comprising approximately 40 subunits and approximately 30 nm across. This pre-pore assembly then refolds to punch a large hole in the lipid bilayer. However, in addition to forming large pores, pneumolysin and other CDCs form smaller lesions characterized by low electrical conductance. Owing to the observation of arc-like (rather than full-ring) oligomers by electron microscopy, it has been hypothesized that smaller oligomers explain smaller functional pores. To investigate whether this is the case, we performed cryo-electron tomography of pneumolysin oligomers on model lipid membranes. We then used sub-tomogram classification and averaging to determine representative membrane-bound low-resolution structures and identified pre-pores versus pores by the presence of membrane within the oligomeric curve. We found pre-pore and pore forms of both complete (ring) and incomplete (arc) oligomers and conclude that arc-shaped oligomeric assemblies of pneumolysin can form pores. As the CDCs are evolutionarily related to the membrane attack complex/perforin family of proteins, which also form variably sized pores, our findings are of relevance to that class of proteins as well.
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Affiliation(s)
- Andreas F-P Sonnen
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
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50
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Crystal structure of listeriolysin O reveals molecular details of oligomerization and pore formation. Nat Commun 2014; 5:3690. [PMID: 24751541 DOI: 10.1038/ncomms4690] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 03/18/2014] [Indexed: 01/17/2023] Open
Abstract
Listeriolysin O (LLO) is an essential virulence factor of Listeria monocytogenes that causes listeriosis. Listeria monocytogenes owes its ability to live within cells to the pH- and temperature-dependent pore-forming activity of LLO, which is unique among cholesterol-dependent cytolysins. LLO enables the bacteria to cross the phagosomal membrane and is also involved in activation of cellular processes, including the modulation of gene expression or intracellular Ca(2+) oscillations. Neither the pore-forming mechanism nor the mechanisms triggering the signalling processes in the host cell are known in detail. Here, we report the crystal structure of LLO, in which we identified regions important for oligomerization and pore formation. Mutants were characterized by determining their haemolytic and Ca(2+) uptake activity. We analysed the pore formation of LLO and its variants on erythrocyte ghosts by electron microscopy and show that pore formation requires precise interface interactions during toxin oligomerization on the membrane.
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