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Panevska A, Čegovnik N, Fortuna K, Vukovič A, Grundner M, Modic Š, Bajc G, Skočaj M, Mravinec Bohte M, Popošek LL, Žigon P, Razinger J, Veranič P, Resnik N, Sepčić K. A single point mutation expands the applicability of ostreolysin A6 in biomedicine. Sci Rep 2023; 13:2149. [PMID: 36750638 PMCID: PMC9905591 DOI: 10.1038/s41598-023-28949-7] [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: 10/18/2022] [Accepted: 01/27/2023] [Indexed: 02/09/2023] Open
Abstract
An aegerolysin protein ostreolysin A6 (OlyA6) binds to cholesterol-complexed sphingomyelin and can be used for specific labelling of lipid rafts. In addition, OlyA6 interacts with even higher affinity with ceramide phosphoethanolamine (CPE), a sphingolipid that dominates in invertebrate cell membranes. In the presence of pleurotolysin B, a protein bearing the membrane-attack complex/perforin domain, OlyA6 forms pores in insect midgut cell membranes and acts as a potent bioinsecticide. It has been shown that a point mutation of glutamate 69 to alanine (E69A) allows OlyA6 to bind to cholesterol-free sphingomyelin. Using artificial lipid membranes and mammalian MDCK cells, we show that this mutation significantly enhances the interaction of OlyA6 with sphingomyelin and CPE, and allows recognition of these sphingolipids even in the absence of cholesterol. Our results suggest that OlyA6 mutant E69A could serve as complementary tool to detect and study cholesterol-associated and free sphingomyelin or CPE in membranes. However, the mutation does not improve the membrane-permeabilizing activity after addition of pleurotolysin B, which was confirmed in toxicity tests on insect and mammalian cell lines, and on Colorado potato beetle larvae.
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Affiliation(s)
- Anastasija Panevska
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia
| | - Nastja Čegovnik
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia
| | - Klavdija Fortuna
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia
| | - Alen Vukovič
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia
| | - Maja Grundner
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia
| | - Špela Modic
- Agricultural Institute of Slovenia, Hacquetova Ulica 17, 1000, Ljubljana, Slovenia
| | - Gregor Bajc
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia
| | - Matej Skočaj
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia
| | - Martina Mravinec Bohte
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia
| | - Lara Larisa Popošek
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia
| | - Primož Žigon
- Agricultural Institute of Slovenia, Hacquetova Ulica 17, 1000, Ljubljana, Slovenia
| | - Jaka Razinger
- Agricultural Institute of Slovenia, Hacquetova Ulica 17, 1000, Ljubljana, Slovenia
| | - Peter Veranič
- Institute of Cell Biology, Faculty of Medicine, University of Ljubljana, Vrazov Trg 2, 1000, Ljubljana, Slovenia
| | - Nataša Resnik
- Institute of Cell Biology, Faculty of Medicine, University of Ljubljana, Vrazov Trg 2, 1000, Ljubljana, Slovenia.
| | - Kristina Sepčić
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia.
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He X, Lu L, Huang P, Yu B, Peng L, Zou L, Ren Y. Insect Cell-Based Models: Cell Line Establishment and Application in Insecticide Screening and Toxicology Research. INSECTS 2023; 14:104. [PMID: 36835673 PMCID: PMC9965340 DOI: 10.3390/insects14020104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 01/07/2023] [Accepted: 01/17/2023] [Indexed: 06/18/2023]
Abstract
During the past decades, research on insect cell culture has grown tremendously. Thousands of lines have been established from different species of insect orders, originating from several tissue sources. These cell lines have often been employed in insect science research. In particular, they have played important roles in pest management, where they have been used as tools to evaluate the activity and explore the toxic mechanisms of insecticide candidate compounds. This review intends to first briefly summarize the progression of insect cell line establishment. Then, several recent studies based on insect cell lines coupled with advanced technologies are introduced. These investigations revealed that insect cell lines can be exploited as novel models with unique advantages such as increased efficiency and reduced cost compared with traditional insecticide research. Most notably, the insect cell line-based models provide a global and in-depth perspective to study the toxicology mechanisms of insecticides. However, challenges and limitations still exist, especially in the connection between in vitro activity and in vivo effectiveness. Despite all this, recent advances have suggested that insect cell line-based models promote the progress and sensible application of insecticides, which benefits pest management.
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Towards Understanding the Function of Aegerolysins. Toxins (Basel) 2022; 14:toxins14090629. [PMID: 36136567 PMCID: PMC9505663 DOI: 10.3390/toxins14090629] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Revised: 09/04/2022] [Accepted: 09/09/2022] [Indexed: 11/17/2022] Open
Abstract
Aegerolysins are remarkable proteins. They are distributed over the tree of life, being relatively widespread in bacteria and fungi, but also present in some insects, plants, protozoa, and viruses. Despite their abundance in cells of certain developmental stages and their presence in secretomes, only a few aegerolysins have been studied in detail. Their function, in particular, is intriguing. Here, we summarize previously published findings on the distribution, molecular interactions, and function of these versatile aegerolysins. They have very diverse protein sequences but a common fold. The machine learning approach of the AlphaFold2 algorithm, which incorporates physical and biological knowledge of protein structures and multisequence alignments, provides us new insights into the aegerolysins and their pore-forming partners, complemented by additional genomic support. We hypothesize that aegerolysins are involved in the mechanisms of competitive exclusion in the niche.
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Towards a Fungal Science That Is Independent of Researchers’ Gender. J Fungi (Basel) 2022; 8:jof8070675. [PMID: 35887432 PMCID: PMC9321353 DOI: 10.3390/jof8070675] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 06/23/2022] [Accepted: 06/24/2022] [Indexed: 02/04/2023] Open
Abstract
The main drivers of gender mainstreaming in basic and clinical research appear to be funding agencies and scientific journals. Some funding agencies have already recognized the importance of their actions for the global development of ideas in science, but further targeted efforts are needed. The challenges for women scientists in fungal research appear to be similar to those in other science, technology, engineering, and mathematics disciplines, although the gender gap in mycology publishing appears to be less pronounced; however, women are underrepresented as last (corresponding) authors. Two examples of best practices to bridge the gap have been promoted in the fungal community: “power hour” and a central resource database for women researchers of fungi and oomycetes. A more balanced ratio of women researchers among (plenary) session speakers, (plenary) session chairs, and committee members at the recent fungal genetics conference is an encouraging sign that the gender gap can be closed. The editorial policy of some journals follows the guidance “Sex and Gender Equality in Research,” and other journals should follow, and indicate the gender ratio among authors and reviewers.
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Grundner M, Munjaković H, Tori T, Sepčić K, Gašperšič R, Oblak Č, Seme K, Guella G, Trenti F, Skočaj M. Ceramide Phosphoethanolamine as a Possible Marker of Periodontal Disease. MEMBRANES 2022; 12:membranes12070655. [PMID: 35877858 PMCID: PMC9324278 DOI: 10.3390/membranes12070655] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 06/22/2022] [Accepted: 06/23/2022] [Indexed: 11/16/2022]
Abstract
Periodontal disease is a chronic oral inflammatory disorder initiated by pathobiontic bacteria found in dental plaques—complex biofilms on the tooth surface. The disease begins as an acute local inflammation of the gingival tissue (gingivitis) and can progress to periodontitis, which eventually leads to the formation of periodontal pockets and ultimately results in tooth loss. The main problem in periodontology is that the diagnosis is based on the assessment of the already obvious tissue damage. Therefore, it is necessary to improve the current diagnostics used to assess periodontal disease. Using lipidomic analyses, we show that both crucial periodontal pathogens, Porphyromonas gingivalis and Tannerella forsythia, synthesize ceramide phosphoethanolamine (CPE) species, membrane sphingolipids not typically found in vertebrates. Previously, it was shown that this particular lipid can be specifically detected by an aegerolysin protein, erylysin A (EryA). Here, we show that EryA can specifically bind to CPE species from the total lipid extract from P. gingivalis. Furthermore, using a fluorescently labelled EryA-mCherry, we were able to detect CPE species in clinical samples of dental plaque from periodontal patients. These results demonstrate the potential of specific periodontal pathogen-derived lipids as biomarkers for periodontal disease and other chronic inflammatory diseases.
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Affiliation(s)
- Maja Grundner
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, 1000 Ljubljana, Slovenia; (M.G.); (H.M.); (T.T.); (K.S.)
| | - Haris Munjaković
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, 1000 Ljubljana, Slovenia; (M.G.); (H.M.); (T.T.); (K.S.)
| | - Tilen Tori
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, 1000 Ljubljana, Slovenia; (M.G.); (H.M.); (T.T.); (K.S.)
| | - Kristina Sepčić
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, 1000 Ljubljana, Slovenia; (M.G.); (H.M.); (T.T.); (K.S.)
| | - Rok Gašperšič
- Faculty of Medicine, University of Ljubljana, Vrazov trg 2, 1000 Ljubljana, Slovenia; (R.G.); (Č.O.); (K.S.)
| | - Čedomir Oblak
- Faculty of Medicine, University of Ljubljana, Vrazov trg 2, 1000 Ljubljana, Slovenia; (R.G.); (Č.O.); (K.S.)
| | - Katja Seme
- Faculty of Medicine, University of Ljubljana, Vrazov trg 2, 1000 Ljubljana, Slovenia; (R.G.); (Č.O.); (K.S.)
| | - Graziano Guella
- Bioorganic Chemistry Laboratory, Department of Physics, University of Trento, Via Sommarive 14, 38123 Trento, Italy; (G.G.); (F.T.)
| | - Francesco Trenti
- Bioorganic Chemistry Laboratory, Department of Physics, University of Trento, Via Sommarive 14, 38123 Trento, Italy; (G.G.); (F.T.)
| | - Matej Skočaj
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, 1000 Ljubljana, Slovenia; (M.G.); (H.M.); (T.T.); (K.S.)
- Correspondence: ; Tel.: +386-1-3203-395
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6
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Yamaji-Hasegawa A, Murate M, Inaba T, Dohmae N, Sato M, Fujimori F, Sako Y, Greimel P, Kobayashi T. A novel sterol-binding protein reveals heterogeneous cholesterol distribution in neurite outgrowth and in late endosomes/lysosomes. Cell Mol Life Sci 2022; 79:324. [PMID: 35644822 PMCID: PMC11072113 DOI: 10.1007/s00018-022-04339-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 04/26/2022] [Accepted: 04/29/2022] [Indexed: 11/24/2022]
Abstract
We identified a mushroom-derived protein, maistero-2 that specifically binds 3-hydroxy sterol including cholesterol (Chol). Maistero-2 bound lipid mixture in Chol-dependent manner with a binding threshold of around 30%. Changing lipid composition did not significantly affect the threshold concentration. EGFP-maistero-2 labeled cell surface and intracellular organelle Chol with higher sensitivity than that of well-established Chol probe, D4 fragment of perfringolysin O. EGFP-maistero-2 revealed increase of cell surface Chol during neurite outgrowth and heterogeneous Chol distribution between CD63-positive and LAMP1-positive late endosomes/lysosomes. The absence of strictly conserved Thr-Leu pair present in Chol-dependent cytolysins suggests a distinct Chol-binding mechanism for maistero-2.
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Affiliation(s)
| | - Motohide Murate
- Lipid Biology Laboratory, RIKEN, 2-1, Hirosawa, Wako-shi, Saitama, 351-0198, Japan
- Cellular Informatics Laboratory, RIKEN CPR, 2-1, Hirosawa, Wako-shi, Saitama, 351-0198, Japan
- UMR 7021, CNRS, Université de Strasbourg, 67401, Illkirch, France
| | - Takehiko Inaba
- Lipid Biology Laboratory, RIKEN, 2-1, Hirosawa, Wako-shi, Saitama, 351-0198, Japan
- Cellular Informatics Laboratory, RIKEN CPR, 2-1, Hirosawa, Wako-shi, Saitama, 351-0198, Japan
| | - Naoshi Dohmae
- Biomolecular Characterization Unit, RIKEN CSRS, 2-1, Hirosawa, Wako-shi, Saitama, 351-0198, Japan
| | - Masayuki Sato
- Yukiguni Maitake Co, Ltd. Yokawa 89, Minamiuonuma, Niigata, 949-6695, Japan
| | - Fumihiro Fujimori
- Laboratory of Biological Science and Technology, Tokyo Kasei University, 1-18-1 Kaga, Itabashi, Tokyo, 173-8062, Japan
| | - Yasushi Sako
- Cellular Informatics Laboratory, RIKEN CPR, 2-1, Hirosawa, Wako-shi, Saitama, 351-0198, Japan
| | - Peter Greimel
- Lipid Biology Laboratory, RIKEN, 2-1, Hirosawa, Wako-shi, Saitama, 351-0198, Japan
| | - Toshihide Kobayashi
- Lipid Biology Laboratory, RIKEN, 2-1, Hirosawa, Wako-shi, Saitama, 351-0198, Japan.
- Cellular Informatics Laboratory, RIKEN CPR, 2-1, Hirosawa, Wako-shi, Saitama, 351-0198, Japan.
- UMR 7021, CNRS, Université de Strasbourg, 67401, Illkirch, France.
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7
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Balbi T, Trenti F, Panevska A, Bajc G, Guella G, Ciacci C, Canonico B, Canesi L, Sepčić K. Ceramide Aminoethylphosphonate as a New Molecular Target for Pore-Forming Aegerolysin-Based Protein Complexes. Front Mol Biosci 2022; 9:902706. [PMID: 35693554 PMCID: PMC9174665 DOI: 10.3389/fmolb.2022.902706] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 04/20/2022] [Indexed: 11/13/2022] Open
Abstract
Ostreolysin A6 (OlyA6) is a 15 kDa protein produced by the oyster mushroom (Pleurotus ostreatus). It belongs to the aegerolysin family of proteins and binds with high affinity to the insect-specific membrane sphingolipid, ceramide phosphoethanolamine (CPE). In concert with its partnering protein with the membrane-attack-complex/perforin domain, pleurotolysin B (PlyB), OlyA6 can form bicomponent 13-meric transmembrane pores in artificial and biological membranes containing the aegerolysin lipid receptor, CPE. This pore formation is the main underlying molecular mechanism of potent and selective insecticidal activity of OlyA6/PlyB complexes against two economically important coleopteran plant pests: the western corn rootworm and the Colorado potato beetle. In contrast to insects, the main sphingolipid in cell membranes of marine invertebrates (i.e., molluscs and cnidarians) is ceramide aminoethylphosphonate (CAEP), a CPE analogue built on a phosphono rather than the usual phosphate group in its polar head. Our targeted lipidomic analyses of the immune cells (hemocytes) of the marine bivalve, the mussel Mytilus galloprovincialis, confirmed the presence of 29.0 mol% CAEP followed by 36.4 mol% of phosphatidylcholine and 34.6 mol% of phosphatidylethanolamine. Further experiments showed the potent binding of OlyA6 to artificial lipid vesicles supplemented with mussel CAEP, and strong lysis of these vesicles by the OlyA6/PlyB mixture. In Mytilus haemocytes, short term exposure (max. 1 h) to the OlyA6/PlyB mixture induced lysosomal membrane destabilization, decreased phagocytic activity, increased Annexin V binding and oxyradical production, and decreased levels of reduced glutathione, indicating rapid damage of endo-lysosomal and plasma membranes and oxidative stress. Our data suggest CAEP as a novel high-affinity receptor for OlyA6 and a target for cytolytic OlyA6/PlyB complexes.
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Affiliation(s)
- Teresa Balbi
- Department of Earth, Environmental and Life Sciences, University of Genoa, Genoa, Italy
| | - Francesco Trenti
- Bioorganic Chemistry Laboratory, Department of Physics, University of Trento, Trento, Italy
| | - Anastasija Panevska
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Gregor Bajc
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Graziano Guella
- Bioorganic Chemistry Laboratory, Department of Physics, University of Trento, Trento, Italy
| | - Caterina Ciacci
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, Italy
| | - Barbara Canonico
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, Italy
| | - Laura Canesi
- Department of Earth, Environmental and Life Sciences, University of Genoa, Genoa, Italy
- *Correspondence: Kristina Sepčić, ; Laura Canesi,
| | - Kristina Sepčić
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
- *Correspondence: Kristina Sepčić, ; Laura Canesi,
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Trenti F, Sandron T, Guella G, Lencioni V. Insect cold-tolerance and lipidome: Membrane lipid composition of two chironomid species differently adapted to cold. Cryobiology 2022; 106:84-90. [DOI: 10.1016/j.cryobiol.2022.03.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 03/07/2022] [Accepted: 03/18/2022] [Indexed: 11/30/2022]
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9
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Hodel AW, Rudd-Schmidt JA, Trapani JA, Voskoboinik I, Hoogenboom BW. Lipid specificity of the immune effector perforin. Faraday Discuss 2021; 232:236-255. [PMID: 34545865 PMCID: PMC8704153 DOI: 10.1039/d0fd00043d] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 08/13/2020] [Indexed: 12/16/2022]
Abstract
Perforin is a pore forming protein used by cytotoxic T lymphocytes to remove cancerous or virus-infected cells during the immune response. During the response, the lymphocyte membrane becomes refractory to perforin function by accumulating densely ordered lipid rafts and externalizing negatively charged lipid species. The dense membrane packing lowers the capacity of perforin to bind, and the negatively charged lipids scavenge any residual protein before pore formation. Using atomic force microscopy on model membrane systems, we here provide insight into the molecular basis of perforin lipid specificity.
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Affiliation(s)
- Adrian W Hodel
- Killer Cell Biology Laboratory, Peter MacCallum Cancer Centre, 305 Grattan Street, Melbourne, VIC 3000, Australia.
- London Centre for Nanotechnology, University College London, 19 Gordon Street, London WC1H 0AH, UK.
- Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Jesse A Rudd-Schmidt
- Killer Cell Biology Laboratory, Peter MacCallum Cancer Centre, 305 Grattan Street, Melbourne, VIC 3000, Australia.
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, VIC 3000, Australia
| | - Joseph A Trapani
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, VIC 3000, Australia
- Cancer Cell Death Laboratory, Peter MacCallum Cancer Centre, 305 Grattan Street, Melbourne, VIC 3000, Australia
| | - Ilia Voskoboinik
- Killer Cell Biology Laboratory, Peter MacCallum Cancer Centre, 305 Grattan Street, Melbourne, VIC 3000, Australia.
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, VIC 3000, Australia
| | - Bart W Hoogenboom
- London Centre for Nanotechnology, University College London, 19 Gordon Street, London WC1H 0AH, UK.
- Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BT, UK
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK
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10
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Kraševec N, Panevska A, Lemež Š, Razinger J, Sepčić K, Anderluh G, Podobnik M. Lipid-Binding Aegerolysin from Biocontrol Fungus Beauveria bassiana. Toxins (Basel) 2021; 13:820. [PMID: 34822604 PMCID: PMC8624791 DOI: 10.3390/toxins13110820] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 11/15/2021] [Accepted: 11/17/2021] [Indexed: 11/16/2022] Open
Abstract
Fungi are the most common pathogens of insects and thus important regulators of their populations. Lipid-binding aegerolysin proteins, which are commonly found in the fungal kingdom, may be involved in several biologically relevant processes including attack and defense against other organisms. Aegerolysins act alone or together with membrane-attack-complex/perforin (MACPF)-like proteins to form transmembrane pores that lead to cell lysis. We performed an in-depth bioinformatics analysis of aegerolysins in entomopathogenic fungi and selected a candidate aegerolysin, beauveriolysin A (BlyA) from Beauveria bassiana. BlyA was expressed as a recombinant protein in Escherichia coli, and purified to further determine its functional and structural properties, including lipid-binding ability. Aegerolysins were found to be encoded in genomes of entomopathogenic fungi, such as Beauveria, Cordyceps, Metarhizium and Ophiocordyceps. Detailed bioinformatics analysis revealed that they are linked to MACPF-like genes in most genomes. We also show that BlyA interacts with an insect-specific membrane lipid. These results were placed in the context of other fungal and bacterial aegerolysins and their partner proteins. We believe that aegerolysins play a role in promoting the entomopathogenic and antagonistic activity of B. bassiana, which is an active ingredient of bioinsecticides.
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Affiliation(s)
- Nada Kraševec
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, SI-1000 Ljubljana, Slovenia; (Š.L.); (G.A.); (M.P.)
| | - Anastasija Panevska
- Department of Biology, Biotechnical Faculty, University of Ljubljana, SI-1000 Ljubljana, Slovenia; (A.P.); (K.S.)
| | - Špela Lemež
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, SI-1000 Ljubljana, Slovenia; (Š.L.); (G.A.); (M.P.)
- Biotechnology, Biotechnical Faculty, University of Ljubljana, SI-1000 Ljubljana, Slovenia
| | - Jaka Razinger
- Plant Protection Department, Agricultural Institute of Slovenia, Hacquetova 17, SI-1000 Ljubljana, Slovenia;
| | - Kristina Sepčić
- Department of Biology, Biotechnical Faculty, University of Ljubljana, SI-1000 Ljubljana, Slovenia; (A.P.); (K.S.)
| | - Gregor Anderluh
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, SI-1000 Ljubljana, Slovenia; (Š.L.); (G.A.); (M.P.)
| | - Marjetka Podobnik
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, SI-1000 Ljubljana, Slovenia; (Š.L.); (G.A.); (M.P.)
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11
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Panevska A, Glavan G, Jemec Kokalj A, Kukuljan V, Trobec T, Žužek MC, Vrecl M, Drobne D, Frangež R, Sepčić K. Effects of Bioinsecticidal Aegerolysin-Based Cytolytic Complexes on Non-Target Organisms. Toxins (Basel) 2021; 13:457. [PMID: 34208927 PMCID: PMC8310125 DOI: 10.3390/toxins13070457] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 06/25/2021] [Accepted: 06/28/2021] [Indexed: 01/05/2023] Open
Abstract
Aegerolysin proteins ostreolysin A6 (OlyA6), pleurotolysin A2 (PlyA2) and erylysin A (EryA) produced by the mushroom genus Pleurotus bind strongly to an invertebrate-specific membrane sphingolipid, and together with a protein partner pleurotolysin B (PlyB), form transmembrane pore complexes. This pore formation is the basis for the selective insecticidal activity of aegerolysin/PlyB complexes against two economically important coleopteran pests: the Colorado potato beetle and the western corn rootworm. In this study, we evaluated the toxicities of these aegerolysin/PlyB complexes using feeding tests with two ecologically important non-target arthropod species: the woodlouse and the honey bee. The mammalian toxicity of the EryA/PlyB complex was also evaluated after intravenous administration to mice. None of the aegerolysin/PlyB complexes were toxic against woodlice, but OlyA6/PlyB and PlyA2/PlyB were toxic to honeybees, with 48 h mean lethal concentrations (LC50) of 0.22 and 0.39 mg/mL, respectively, in their food. EryA/PlyB was also tested intravenously in mice up to 3 mg/kg body mass, without showing toxicity. With no toxicity seen for EryA/PlyB for environmentally beneficial arthropods and mammals at the tested concentrations, these EryA/PlyB complexes are of particular interest for development of new bioinsecticides for control of selected coleopteran pests.
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Affiliation(s)
- Anastasija Panevska
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; (A.P.); (G.G.); (A.J.K.); (D.D.)
| | - Gordana Glavan
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; (A.P.); (G.G.); (A.J.K.); (D.D.)
| | - Anita Jemec Kokalj
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; (A.P.); (G.G.); (A.J.K.); (D.D.)
| | - Veronika Kukuljan
- Department of Biotechnology, University of Rijeka, 51000 Rijeka, Croatia;
| | - Tomaž Trobec
- Institute of Preclinical Sciences, Veterinary Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; (T.T.); (M.C.Ž.); (M.V.)
| | - Monika Cecilija Žužek
- Institute of Preclinical Sciences, Veterinary Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; (T.T.); (M.C.Ž.); (M.V.)
| | - Milka Vrecl
- Institute of Preclinical Sciences, Veterinary Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; (T.T.); (M.C.Ž.); (M.V.)
| | - Damjana Drobne
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; (A.P.); (G.G.); (A.J.K.); (D.D.)
| | - Robert Frangež
- Institute of Preclinical Sciences, Veterinary Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; (T.T.); (M.C.Ž.); (M.V.)
| | - Kristina Sepčić
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; (A.P.); (G.G.); (A.J.K.); (D.D.)
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Milijaš Jotić M, Panevska A, Iacovache I, Kostanjšek R, Mravinec M, Skočaj M, Zuber B, Pavšič A, Razinger J, Modic Š, Trenti F, Guella G, Sepčić K. Dissecting Out the Molecular Mechanism of Insecticidal Activity of Ostreolysin A6/Pleurotolysin B Complexes on Western Corn Rootworm. Toxins (Basel) 2021; 13:toxins13070455. [PMID: 34209983 PMCID: PMC8310357 DOI: 10.3390/toxins13070455] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 06/24/2021] [Accepted: 06/25/2021] [Indexed: 02/04/2023] Open
Abstract
Ostreolysin A6 (OlyA6) is a protein produced by the oyster mushroom (Pleurotus ostreatus). It binds to membrane sphingomyelin/cholesterol domains, and together with its protein partner, pleurotolysin B (PlyB), it forms 13-meric transmembrane pore complexes. Further, OlyA6 binds 1000 times more strongly to the insect-specific membrane sphingolipid, ceramide phosphoethanolamine (CPE). In concert with PlyB, OlyA6 has potent and selective insecticidal activity against the western corn rootworm. We analysed the histological alterations of the midgut wall columnar epithelium of western corn rootworm larvae fed with OlyA6/PlyB, which showed vacuolisation of the cell cytoplasm, swelling of the apical cell surface into the gut lumen, and delamination of the basal lamina underlying the epithelium. Additionally, cryo-electron microscopy was used to explore the membrane interactions of the OlyA6/PlyB complex using lipid vesicles composed of artificial lipids containing CPE, and western corn rootworm brush border membrane vesicles. Multimeric transmembrane pores were formed in both vesicle preparations, similar to those described for sphingomyelin/cholesterol membranes. These results strongly suggest that the molecular mechanism of insecticidal action of OlyA6/PlyB arises from specific interactions of OlyA6 with CPE, and the consequent formation of transmembrane pores in the insect midgut.
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Affiliation(s)
- Matej Milijaš Jotić
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; (M.M.J.); (A.P.); (R.K.); (M.M.); (M.S.); (A.P.)
| | - Anastasija Panevska
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; (M.M.J.); (A.P.); (R.K.); (M.M.); (M.S.); (A.P.)
| | - Ioan Iacovache
- Institute of Anatomy, University of Bern, 3012 Bern, Switzerland; (I.I.); (B.Z.)
| | - Rok Kostanjšek
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; (M.M.J.); (A.P.); (R.K.); (M.M.); (M.S.); (A.P.)
| | - Martina Mravinec
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; (M.M.J.); (A.P.); (R.K.); (M.M.); (M.S.); (A.P.)
| | - Matej Skočaj
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; (M.M.J.); (A.P.); (R.K.); (M.M.); (M.S.); (A.P.)
| | - Benoît Zuber
- Institute of Anatomy, University of Bern, 3012 Bern, Switzerland; (I.I.); (B.Z.)
| | - Ana Pavšič
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; (M.M.J.); (A.P.); (R.K.); (M.M.); (M.S.); (A.P.)
| | - Jaka Razinger
- Agricultural Institute of Slovenia, 1000 Ljubljana, Slovenia; (J.R.); (Š.M.)
| | - Špela Modic
- Agricultural Institute of Slovenia, 1000 Ljubljana, Slovenia; (J.R.); (Š.M.)
| | - Francesco Trenti
- Bioorganic Chemistry Laboratory, Department of Physics, University of Trento, 38123 Trento, Italy; (F.T.); (G.G.)
| | - Graziano Guella
- Bioorganic Chemistry Laboratory, Department of Physics, University of Trento, 38123 Trento, Italy; (F.T.); (G.G.)
| | - Kristina Sepčić
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; (M.M.J.); (A.P.); (R.K.); (M.M.); (M.S.); (A.P.)
- Correspondence: ; Tel.: +386-1-320-3419
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What Can Mushroom Proteins Teach Us about Lipid Rafts? MEMBRANES 2021; 11:membranes11040264. [PMID: 33917311 PMCID: PMC8067419 DOI: 10.3390/membranes11040264] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Revised: 03/31/2021] [Accepted: 03/31/2021] [Indexed: 12/25/2022]
Abstract
The lipid raft hypothesis emerged as a need to explain the lateral organization and behavior of lipids in the environment of biological membranes. The idea, that lipids segregate in biological membranes to form liquid-disordered and liquid-ordered states, was faced with a challenge: to show that lipid-ordered domains, enriched in sphingomyelin and cholesterol, actually exist in vivo. A great deal of indirect evidence and the use of lipid-binding probes supported this idea, but there was a lack of tools to demonstrate the existence of such domains in living cells. A whole new toolbox had to be invented to biochemically characterize lipid rafts and to define how they are involved in several cellular functions. A potential solution came from basic biochemical experiments in the late 1970s, showing that some mushroom extracts exert hemolytic activities. These activities were later assigned to aegerolysin-based sphingomyelin/cholesterol-specific cytolytic protein complexes. Recently, six sphingomyelin/cholesterol binding proteins from different mushrooms have been identified and have provided some insight into the nature of sphingomyelin/cholesterol-rich domains in living vertebrate cells. In this review, we dissect the accumulated knowledge and introduce the mushroom lipid raft binding proteins as molecules of choice to study the dynamics and origins of these liquid-ordered domains in mammalian cells.
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Crystal structure of RahU, an aegerolysin protein from the human pathogen Pseudomonas aeruginosa, and its interaction with membrane ceramide phosphorylethanolamine. Sci Rep 2021; 11:6572. [PMID: 33753805 PMCID: PMC7985367 DOI: 10.1038/s41598-021-85956-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 03/08/2021] [Indexed: 12/15/2022] Open
Abstract
Aegerolysins are proteins produced by bacteria, fungi, plants and protozoa. The most studied fungal aegerolysins share a common property of interacting with membranes enriched with cholesterol in combination with either sphingomyelin or ceramide phosphorylethanolamine (CPE), major sphingolipids in the cell membranes of vertebrates and invertebrates, respectively. However, genome analyses show a particularly high frequency of aegerolysin genes in bacteria, including the pathogenic genera Pseudomonas and Vibrio; these are human pathogens of high clinical relevance and can thrive in a variety of other species. The knowledge on bacterial aegerolysin-lipid interactions is scarce. We show that Pseudomonas aeruginosa aegerolysin RahU interacts with CPE, but not with sphingomyelin-enriched artificial membranes, and that RahU interacts with the insect cell line producing CPE. We report crystal structures of RahU alone and in complex with tris(hydroxymethyl)aminomethane (Tris), which, like the phosphorylethanolamine head group of CPE, contains a primary amine. The RahU structures reveal that the two loops proximal to the amino terminus form a cavity that accommodates Tris, and that the flexibility of these two loops is important for this interaction. We show that Tris interferes with CPE-enriched membranes for binding to RahU, implying on the importance of the ligand cavity between the loops and its proximity in RahU membrane interaction. We further support this by studying the interaction of single amino acid substitution mutants of RahU with the CPE-enriched membranes. Our results thus represent a starting point for a better understanding of the role of P. aeruginosa RahU, and possibly other bacterial aegerolysins, in bacterial interactions with other organisms.
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Kraševec N, Novak M, Barat S, Skočaj M, Sepčić K, Anderluh G. Unconventional Secretion of Nigerolysins A from Aspergillus Species. Microorganisms 2020; 8:E1973. [PMID: 33322461 PMCID: PMC7763983 DOI: 10.3390/microorganisms8121973] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 12/04/2020] [Accepted: 12/09/2020] [Indexed: 01/05/2023] Open
Abstract
Aegerolysins are small lipid-binding proteins particularly abundant in fungi. Aegerolysins from oyster mushrooms interact with an insect-specific membrane lipid and, together with MACPF proteins produced by the same organism, form pesticidal pore-forming complexes. The specific interaction with the same membrane lipid was recently demonstrated for nigerolysin A2 (NigA2), an aegerolysin from Aspergillus niger. In Aspergillus species, the aegerolysins were frequently found as secreted proteins, indicating their function in fungal defense. Using immunocytochemistry and live-cell imaging we investigated the subcellular localization of the nigerolysins A in A. niger, while their secretion was addressed by secretion prediction and Western blotting. We show that both nigerolysins A are leaderless proteins that reach the cell exterior by an unconventional protein secretion. NigA proteins are evenly distributed in the cytoplasm of fungal hyphae. A detailed bioinformatics analysis of Aspergillus aegerolysins suggests that the same function occurs only in a limited number of aegerolysins. From alignment, analysis of chromosomal loci, orthology, synteny, and phylogeny it follows that the same or a similar function described for pairs of pesticidal proteins of Pleurotus sp. can be expected in species of the subgenus Circumdati, section Nigri, series Nigri, and some other species with adjacent pairs of putative pesticidal proteins.
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Affiliation(s)
- Nada Kraševec
- National Institute of Chemistry, SI-1000 Ljubljana, Slovenia; (S.B.); (G.A.)
| | - Maruša Novak
- Department of Biology, Biotechnical Faculty, University of Ljubljana, SI-1000 Ljubljana, Slovenia; (M.N.); (M.S.); (K.S.)
| | - Simona Barat
- National Institute of Chemistry, SI-1000 Ljubljana, Slovenia; (S.B.); (G.A.)
- Department of Biology, Biotechnical Faculty, University of Ljubljana, SI-1000 Ljubljana, Slovenia; (M.N.); (M.S.); (K.S.)
| | - Matej Skočaj
- Department of Biology, Biotechnical Faculty, University of Ljubljana, SI-1000 Ljubljana, Slovenia; (M.N.); (M.S.); (K.S.)
| | - Kristina Sepčić
- Department of Biology, Biotechnical Faculty, University of Ljubljana, SI-1000 Ljubljana, Slovenia; (M.N.); (M.S.); (K.S.)
| | - Gregor Anderluh
- National Institute of Chemistry, SI-1000 Ljubljana, Slovenia; (S.B.); (G.A.)
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Panevska A, Skočaj M, Modic Š, Razinger J, Sepčić K. Aegerolysins from the fungal genus Pleurotus - Bioinsecticidal proteins with multiple potential applications. J Invertebr Pathol 2020; 186:107474. [PMID: 32971130 DOI: 10.1016/j.jip.2020.107474] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 09/08/2020] [Accepted: 09/10/2020] [Indexed: 12/24/2022]
Abstract
The aegerolysin proteins ostreolysin A6, pleurotolysin A2 and erylysin A are produced by mushrooms of the genus Pleurotus. These aegerolysins can interact specifically with sphingolipid-enriched membranes. In particular, they strongly bind insect cells and to artificial lipid membranes that contain physiologically relevant concentrations of the main invertebrate-specific sphingolipid, ceramide phosphoethanolamine. Moreover, the aegerolysins permeabilise these membranes when combined with their protein partner pleurotolysin B, which contains a membrane-attack-complex/perforin domain. These aegerolysin/ pleurotolysin B complexes show strong and selective toxicity towards western corn rootworm larvae and adults and Colorado potato beetle larvae. Their insecticidal activities arise through aegerolysin binding to ceramide phosphoethanolamine in the insect midgut. This mode of membrane binding is different from those described for similar aegerolysin-based complexes of bacterial origin (e.g., Cry34Ab1/Cry35Ab1), or other Bacillus thuringiensis proteinaceous crystal toxins, which associate with protein receptors. The ability of Pleurotus aegerolysins to specifically interact with sphingolipid-enriched domains in mammalian cells can be further exploited to visualize lipid rafts in living cells, and to treat certain types of tumours and metabolic disorders. Finally, these proteins can strongly enhance fruiting initiation of P. ostreatus even when applied externally. In this review, we summarise the current knowledge of the potential biotechnological and biomedical applications of the Pleurotus aegerolysins, either alone or when complexed with pleurotolysin B, with special emphasis on their bioinsecticidal effects.
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Affiliation(s)
- Anastasija Panevska
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000 Ljubljana, Slovenia.
| | - Matej Skočaj
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000 Ljubljana, Slovenia.
| | - Špela Modic
- Plant Protection Department, Agricultural Institute of Slovenia, Hacquetova 17, 1000 Ljubljana, Slovenia.
| | - Jaka Razinger
- Plant Protection Department, Agricultural Institute of Slovenia, Hacquetova 17, 1000 Ljubljana, Slovenia.
| | - Kristina Sepčić
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000 Ljubljana, Slovenia.
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