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Schiphof K, Kawauchi M, Tsuji K, Yoshimi A, Tanaka C, Nakazawa T, Honda Y. Functional analysis of basidiomycete specific chitin synthase genes in the agaricomycete fungus Pleurotus ostreatus. Fungal Genet Biol 2024; 172:103893. [PMID: 38657898 DOI: 10.1016/j.fgb.2024.103893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 04/10/2024] [Accepted: 04/17/2024] [Indexed: 04/26/2024]
Abstract
Chitin is an essential structural component of fungal cell walls composed of transmembrane proteins called chitin synthases (CHSs), which have a large range of reported effects in ascomycetes; however, are poorly understood in agaricomycetes. In this study, evolutionary and molecular genetic analyses of chs genes were conducted using genomic information from nine ascomycete and six basidiomycete species. The results support the existence of seven previously classified chs clades and the discovery of three novel basidiomycete-specific clades (BI-BIII). The agaricomycete fungus Pleurotus ostreatus was observed to have nine putative chs genes, four of which were basidiomycete-specific. Three of these basidiomycete specific genes were disrupted in the P. ostreatus 20b strain (ku80 disruptant) through homologous recombination and transformants were obtained (Δchsb2, Δchsb3, and Δchsb4). Despite numerous transformations Δchsb1 was unobtainable, suggesting disruption of this gene causes a crucial negative effect in P. ostreatus. Disruption of these chsb2-4 genes caused sparser mycelia with rougher surfaces and shorter aerial hyphae. They also caused increased sensitivity to cell wall and membrane stress, thinner cell walls, and overexpression of other chitin and glucan synthases. These genes have distinct roles in the structural formation of aerial hyphae and cell walls, which are important for understanding basidiomycete evolution in filamentous fungi.
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Affiliation(s)
- Kim Schiphof
- Graduate School of Agriculture, Kyoto University, Kitashirakawaoiwakecho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Moriyuki Kawauchi
- Graduate School of Agriculture, Kyoto University, Kitashirakawaoiwakecho, Sakyo-ku, Kyoto 606-8502, Japan.
| | - Kenya Tsuji
- Graduate School of Agriculture, Kyoto University, Kitashirakawaoiwakecho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Akira Yoshimi
- Graduate School of Agriculture, Kyoto University, Kitashirakawaoiwakecho, Sakyo-ku, Kyoto 606-8502, Japan; Graduate School of Global Environmental Studies, Kyoto University, Kitashirakawaoiwakecho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Chihiro Tanaka
- Graduate School of Agriculture, Kyoto University, Kitashirakawaoiwakecho, Sakyo-ku, Kyoto 606-8502, Japan; Graduate School of Global Environmental Studies, Kyoto University, Kitashirakawaoiwakecho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Takehito Nakazawa
- Graduate School of Agriculture, Kyoto University, Kitashirakawaoiwakecho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Yoichi Honda
- Graduate School of Agriculture, Kyoto University, Kitashirakawaoiwakecho, Sakyo-ku, Kyoto 606-8502, Japan
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Shin S, Park J, Yang L, Kim H, Choi GJ, Lee YW, Kim JE, Son H. Con7 is a key transcription regulator for conidiogenesis in the plant pathogenic fungus Fusarium graminearum. mSphere 2024; 9:e0081823. [PMID: 38591889 PMCID: PMC11237738 DOI: 10.1128/msphere.00818-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Accepted: 03/18/2024] [Indexed: 04/10/2024] Open
Abstract
The mycelium of the plant pathogenic fungus Fusarium graminearum exhibits distinct structures for vegetative growth, asexual sporulation, sexual development, virulence, and chlamydospore formation. These structures are vital for the survival and pathogenicity of the fungus, necessitating precise regulation based on environmental cues. Initially identified in Magnaporthe oryzae, the transcription factor Con7p regulates conidiation and infection-related morphogenesis, but not vegetative growth. We characterized the Con7p ortholog FgCon7, and deletion of FgCON7 resulted in severe defects in conidium production, virulence, sexual development, and vegetative growth. The mycelia of the deletion mutant transformed into chlamydospore-like structures with high chitin level accumulation. Notably, boosting FgABAA expression partially alleviated developmental issues in the FgCON7 deletion mutant. Chromatin immunoprecipitation (ChIP)-quantitative PCR (qPCR) analysis confirmed a direct genetic link between FgABAA and FgCON7. Furthermore, the chitin synthase gene Fg6550 (FGSG_06550) showed significant upregulation in the FgCON7 deletion mutant, and altering FgCON7 expression affected cell wall integrity. Further research will focus on understanding the behavior of the chitin synthase gene and its regulation by FgCon7 in F. graminearum. This study contributes significantly to our understanding of the genetic pathways that regulate hyphal differentiation and conidiation in this plant pathogenic fungus. IMPORTANCE The ascomycete fungus Fusarium graminearum is the primary cause of head blight disease in wheat and barley, as well as ear and stalk rot in maize. Given the importance of conidia and ascospores in the disease cycle of F. graminearum, precise spatiotemporal regulation of these biological processes is crucial. In this study, we characterized the Magnaporthe oryzae Con7p ortholog and discovered that FgCon7 significantly influences various crucial aspects of fungal development and pathogenicity. Notably, overexpression of FgABAA partially restored developmental defects in the FgCON7 deletion mutant. ChIP-qPCR analysis confirmed a direct genetic link between FgABAA and FgCON7. Furthermore, our research revealed a clear correlation between FgCon7 and chitin accumulation and the expression of chitin synthase genes. These findings offer valuable insights into the genetic mechanisms regulating conidiation and the significance of mycelial differentiation in this plant pathogenic fungus.
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Affiliation(s)
- Soobin Shin
- Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
| | - Jiyeun Park
- Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
| | - Lin Yang
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Hun Kim
- Eco-friendly New Materials Research Group, Research Center for Biobased Chemistry, Division of Convergence Chemistry, Korea Research Institute of Chemical Technology, Daejeon, South Korea
| | - Gyung Ja Choi
- Eco-friendly New Materials Research Group, Research Center for Biobased Chemistry, Division of Convergence Chemistry, Korea Research Institute of Chemical Technology, Daejeon, South Korea
| | - Yin-Won Lee
- Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
| | - Jung-Eun Kim
- Research Institute of Climate Change and Agriculture, National Institute of Horticultural and Herbal Science, Jeju, South Korea
| | - Hokyoung Son
- Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
- Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, South Korea
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3
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Brauer VS, Pessoni AM, Freitas MS, Cavalcanti-Neto MP, Ries LNA, Almeida F. Chitin Biosynthesis in Aspergillus Species. J Fungi (Basel) 2023; 9:jof9010089. [PMID: 36675910 PMCID: PMC9865612 DOI: 10.3390/jof9010089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 12/14/2022] [Accepted: 12/17/2022] [Indexed: 01/11/2023] Open
Abstract
The fungal cell wall (FCW) is a dynamic structure responsible for the maintenance of cellular homeostasis, and is essential for modulating the interaction of the fungus with its environment. It is composed of proteins, lipids, pigments and polysaccharides, including chitin. Chitin synthesis is catalyzed by chitin synthases (CS), and up to eight CS-encoding genes can be found in Aspergillus species. This review discusses in detail the chitin synthesis and regulation in Aspergillus species, and how manipulation of chitin synthesis pathways can modulate fungal growth, enzyme production, virulence and susceptibility to antifungal agents. More specifically, the metabolic steps involved in chitin biosynthesis are described with an emphasis on how the initiation of chitin biosynthesis remains unknown. A description of the classification, localization and transport of CS was also made. Chitin biosynthesis is shown to underlie a complex regulatory network, with extensive cross-talks existing between the different signaling pathways. Furthermore, pathways and recently identified regulators of chitin biosynthesis during the caspofungin paradoxical effect (CPE) are described. The effect of a chitin on the mammalian immune system is also discussed. Lastly, interference with chitin biosynthesis may also be beneficial for biotechnological applications. Even after more than 30 years of research, chitin biosynthesis remains a topic of current interest in mycology.
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Affiliation(s)
- Veronica S. Brauer
- Department of Biochemistry and Immunology, Ribeirao Preto Medical School, University of Sao Paulo, Sao Paulo 01000-000, Brazil
| | - André M. Pessoni
- Department of Biochemistry and Immunology, Ribeirao Preto Medical School, University of Sao Paulo, Sao Paulo 01000-000, Brazil
| | - Mateus S. Freitas
- Department of Biochemistry and Immunology, Ribeirao Preto Medical School, University of Sao Paulo, Sao Paulo 01000-000, Brazil
| | - Marinaldo P. Cavalcanti-Neto
- Integrated Laboratory of Morphofunctional Sciences, Institute of Biodiversity and Sustainability (NUPEM), Federal University of Rio de Janeiro, Rio de Janeiro 27965-045, Brazil
| | - Laure N. A. Ries
- MRC Centre for Medical Mycology, University of Exeter, Exeter EX4 4QD, UK
- Correspondence: (L.N.A.R.); (F.A.)
| | - Fausto Almeida
- Department of Biochemistry and Immunology, Ribeirao Preto Medical School, University of Sao Paulo, Sao Paulo 01000-000, Brazil
- Correspondence: (L.N.A.R.); (F.A.)
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4
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Khokhani D, Carrera Carriel C, Vayla S, Irving TB, Stonoha-Arther C, Keller NP, Ané JM. Deciphering the Chitin Code in Plant Symbiosis, Defense, and Microbial Networks. Annu Rev Microbiol 2021; 75:583-607. [PMID: 34623896 DOI: 10.1146/annurev-micro-051921-114809] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Chitin is a structural polymer in many eukaryotes. Many organisms can degrade chitin to defend against chitinous pathogens or use chitin oligomers as food. Beneficial microorganisms like nitrogen-fixing symbiotic rhizobia and mycorrhizal fungi produce chitin-based signal molecules called lipo-chitooligosaccharides (LCOs) and short chitin oligomers to initiate a symbiotic relationship with their compatible hosts and exchange nutrients. A recent study revealed that a broad range of fungi produce LCOs and chitooligosaccharides (COs), suggesting that these signaling molecules are not limited to beneficial microbes. The fungal LCOs also affect fungal growth and development, indicating that the roles of LCOs beyond symbiosis and LCO production may predate mycorrhizal symbiosis. This review describes the diverse structures of chitin; their perception by eukaryotes and prokaryotes; and their roles in symbiotic interactions, defense, and microbe-microbe interactions. We also discuss potential strategies of fungi to synthesize LCOs and their roles in fungi with different lifestyles.
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Affiliation(s)
- Devanshi Khokhani
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA; , , , , , .,Current affiliation: Department of Plant Pathology, University of Minnesota, Saint Paul, Minnesota 55108, USA;
| | - Cristobal Carrera Carriel
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA; , , , , ,
| | - Shivangi Vayla
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA; , , , , ,
| | - Thomas B Irving
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA; , , , , ,
| | - Christina Stonoha-Arther
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA; , , , , ,
| | - Nancy P Keller
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA; , , , , , .,Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Jean-Michel Ané
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA; , , , , , .,Department of Agronomy, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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5
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Major Facilitator Superfamily Transporter Gene FgMFS1 Is Essential for Fusarium graminearum to Deal with Salicylic Acid Stress and for Its Pathogenicity towards Wheat. Int J Mol Sci 2021; 22:ijms22168497. [PMID: 34445203 PMCID: PMC8395176 DOI: 10.3390/ijms22168497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 08/03/2021] [Accepted: 08/04/2021] [Indexed: 11/24/2022] Open
Abstract
Wheat is a major staple food crop worldwide, due to its total yield and unique processing quality. Its grain yield and quality are threatened by Fusarium head blight (FHB), which is mainly caused by Fusarium graminearum. Salicylic acid (SA) has a strong and toxic effect on F. graminearum and is a hopeful target for sustainable control of FHB. F. graminearum is capable of efficientdealing with SA stress. However, the underlying mechanisms remain unclear. Here, we characterized FgMFS1 (FGSG_03725), a major facilitator superfamily (MFS) transporter gene in F. graminearum. FgMFS1 was highly expressed during infection and was upregulated by SA. The predicted three-dimensional structure of the FgMFS1 protein was consistent with the schematic for the antiporter. The subcellular localization experiment indicated that FgMFS1 was usually expressed in the vacuole of hyphae, but was alternatively distributed in the cell membrane under SA treatment, indicating an element of F. graminearum in response to SA. ΔFgMFS1 (loss of function mutant of FgMFS1) showed enhanced sensitivity to SA, less pathogenicity towards wheat, and reduced DON production under SA stress. Re-introduction of a functional FgMFS1 gene into ∆FgMFS1 recovered the mutant phenotypes. Wheat spikes inoculated with ΔFgMFS1 accumulated more SA when compared to those inoculated with the wild-type strain. Ecotopic expression of FgMFS1 in yeast enhanced its tolerance to SA as expected, further demonstrating that FgMFS1 functions as an SA exporter. In conclusion, FgMFS1 encodes an SA exporter in F. graminearum, which is critical for its response to wheat endogenous SA and pathogenicity towards wheat.
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Forster H, Shuai B. Exogenous siRNAs against chitin synthase gene suppress the growth of the pathogenic fungus Macrophomina phaseolina. Mycologia 2020; 112:699-710. [DOI: 10.1080/00275514.2020.1753467] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Heather Forster
- Department of Biological Sciences, Wichita State University, 1845 Fairmount Street, Wichita, Kansas 67260
| | - Bin Shuai
- Department of Biological Sciences, Wichita State University, 1845 Fairmount Street, Wichita, Kansas 67260
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7
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Varlamov VP, Il'ina AV, Shagdarova BT, Lunkov AP, Mysyakina IS. Chitin/Chitosan and Its Derivatives: Fundamental Problems and Practical Approaches. BIOCHEMISTRY (MOSCOW) 2020; 85:S154-S176. [PMID: 32087058 DOI: 10.1134/s0006297920140084] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In this review, we present the data on the natural occurrence of chitin and its partially or fully deacetylated derivative chitosan, as well as their properties, methods of modification, and potential applications of derivatives with bactericidal, fungicidal, and antioxidant activities. The structure and physicochemical characteristics of the polymers, their functions, and features of chitin microbial synthesis and degradation, including the processes occurring in nature, are described. New data on the hydrolytic microorganisms capable of chitin degradation under extreme conditions are presented. Special attention is focused on the effect of physicochemical characteristics of chitosan, including molecular weight, degree of deacetylation, polydispersity index, and number of amino group derivatives (quaternized, succinyl, etc.) on the antimicrobial and antioxidant properties of modified polymers that can be of particular interest for biotechnology, medicine, and agriculture. Analysis of the available literature data confirms the importance of fundamental research to broaden our knowledge on the occurrence of chitin and chitosan in nature, their role in global biosphere cycles, and prospects of applied research aimed at using chitin, chitosan, and their derivatives in various aspects of human activity.
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Affiliation(s)
- V P Varlamov
- Laboratory of Biopolymer Engineering, Institute of Bioengineering, Federal Research Center "Fundamentals of Biotechnology", Russian Academy of Sciences, Moscow, 117312, Russia.
| | - A V Il'ina
- Laboratory of Biopolymer Engineering, Institute of Bioengineering, Federal Research Center "Fundamentals of Biotechnology", Russian Academy of Sciences, Moscow, 117312, Russia
| | - B Ts Shagdarova
- Laboratory of Biopolymer Engineering, Institute of Bioengineering, Federal Research Center "Fundamentals of Biotechnology", Russian Academy of Sciences, Moscow, 117312, Russia
| | - A P Lunkov
- Laboratory of Biopolymer Engineering, Institute of Bioengineering, Federal Research Center "Fundamentals of Biotechnology", Russian Academy of Sciences, Moscow, 117312, Russia
| | - I S Mysyakina
- Winogradsky Institute of Microbiology, Federal Research Center "Fundamentals of Biotechnology", Russian Academy of Sciences, Moscow, 117312, Russia
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8
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Backes A, Hausman JF, Renaut J, Ait Barka E, Jacquard C, Guerriero G. Expression Analysis of Cell Wall-Related Genes in the Plant Pathogenic Fungus Drechslera teres. Genes (Basel) 2020; 11:E300. [PMID: 32178281 PMCID: PMC7140844 DOI: 10.3390/genes11030300] [Citation(s) in RCA: 4] [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: 02/14/2020] [Revised: 03/03/2020] [Accepted: 03/09/2020] [Indexed: 02/05/2023] Open
Abstract
Drechslera teres (D. teres) is an ascomycete, responsible for net blotch, the most serious barley disease causing an important economic impact. The cell wall is a crucial structure for the growth and development of fungi. Thus, understanding cell wall structure, composition and biosynthesis can help in designing new strategies for pest management. Despite the severity and economic impact of net blotch, this is the first study analyzing the cell wall-related genes in D. teres. We have identified key genes involved in the synthesis/remodeling of cell wall polysaccharides, namely chitin, β-(1,3)-glucan and mixed-linkage glucan synthases, as well as endo/exoglucanases and a mitogen-activated protein kinase. We have also analyzed the differential expression of these genes in D. teres spores and in the mycelium after cultivation on different media, as well as in the presence of Paraburkholderia phytofirmans strain PsJN, a plant growth-promoting bacterium (PGPB). The targeted gene expression analysis shows higher gene expression in the spores and in the mycelium with the application of PGPB. Besides analyzing key cell-wall-related genes, this study also identifies the most suitable reference genes to normalize qPCR results in D. teres, thus serving as a basis for future molecular studies on this ascomycete.
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Affiliation(s)
- Aurélie Backes
- Unité de Recherche Résistance Induite et Bio-protection des Plantes—EA 4707, Université de Reims Champagne-Ardenne, UFR Sciences Exactes et Naturelles, SFR Condorcet FR CNRS 3417, Moulin de la Housse—Bâtiment 18, BP 1039, 51687 Reims Cedex 2, France; (A.B.); (E.A.B.)
| | - Jean-Francois Hausman
- Environmental Research and Innovation (ERIN) Department, Luxembourg Institute of Science and Technology (LIST), L-4940 Hautcharage, Luxembourg; (J.-F.H.); (J.R.)
| | - Jenny Renaut
- Environmental Research and Innovation (ERIN) Department, Luxembourg Institute of Science and Technology (LIST), L-4940 Hautcharage, Luxembourg; (J.-F.H.); (J.R.)
| | - Essaid Ait Barka
- Unité de Recherche Résistance Induite et Bio-protection des Plantes—EA 4707, Université de Reims Champagne-Ardenne, UFR Sciences Exactes et Naturelles, SFR Condorcet FR CNRS 3417, Moulin de la Housse—Bâtiment 18, BP 1039, 51687 Reims Cedex 2, France; (A.B.); (E.A.B.)
| | - Cédric Jacquard
- Unité de Recherche Résistance Induite et Bio-protection des Plantes—EA 4707, Université de Reims Champagne-Ardenne, UFR Sciences Exactes et Naturelles, SFR Condorcet FR CNRS 3417, Moulin de la Housse—Bâtiment 18, BP 1039, 51687 Reims Cedex 2, France; (A.B.); (E.A.B.)
| | - Gea Guerriero
- Environmental Research and Innovation (ERIN) Department, Luxembourg Institute of Science and Technology (LIST), L-4940 Hautcharage, Luxembourg; (J.-F.H.); (J.R.)
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9
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Mamun MAA, Katayama T, Cao W, Nakamura S, Maruyama JI. A novel Pezizomycotina-specific protein with gelsolin domains regulates contractile actin ring assembly and constriction in perforated septum formation. Mol Microbiol 2020; 113:964-982. [PMID: 31965663 DOI: 10.1111/mmi.14463] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 01/13/2020] [Accepted: 01/13/2020] [Indexed: 12/29/2022]
Abstract
Septum formation in fungi is equivalent to cytokinesis. It differs mechanistically in filamentous ascomycetes (Pezizomycotina) from that of ascomycete yeasts by the retention of a central septal pore in the former group. However, septum formation in both groups is accomplished by contractile actin ring (CAR) assembly and constriction. The specific components regulating septal pore organization during septum formation are poorly understood. In this study, a novel Pezizomycotina-specific actin regulatory protein GlpA containing gelsolin domains was identified using bioinformatics. A glpA deletion mutant exhibited increased distances between septa, abnormal septum morphology and defective regulation of septal pore closure. In glpA deletion mutant hyphae, overaccumulation of actin filament (F-actin) was observed, and the CAR was abnormal with improper assembly and failure in constriction. In wild-type cells, GlpA was found at the septum formation site similarly to the CAR. The N-terminal 329 residues of GlpA are required for its localization to the septum formation site and essential for proper septum formation, while its C-terminal gelsolin domains are required for the regular CAR dynamics during septum formation. Finally, in this study we elucidated a novel Pezizomycotina-specific actin modulating component, which participates in septum formation by regulating the CAR dynamics.
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Affiliation(s)
| | - Takuya Katayama
- Department of Biotechnology, The University of Tokyo, Tokyo, Japan.,Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Tokyo, Japan
| | - Wei Cao
- Faculty of Information Networking for Innovation and Design, Department of Information Networking for Innovation and Design, Toyo University, Tokyo, Japan
| | - Shugo Nakamura
- Faculty of Information Networking for Innovation and Design, Department of Information Networking for Innovation and Design, Toyo University, Tokyo, Japan
| | - Jun-Ichi Maruyama
- Department of Biotechnology, The University of Tokyo, Tokyo, Japan.,Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Tokyo, Japan
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10
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Gandía M, Garrigues S, Bolós B, Manzanares P, Marcos JF. The Myosin Motor Domain-Containing Chitin Synthases Are Involved in Cell Wall Integrity and Sensitivity to Antifungal Proteins in Penicillium digitatum. Front Microbiol 2019; 10:2400. [PMID: 31681248 PMCID: PMC6813208 DOI: 10.3389/fmicb.2019.02400] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 10/04/2019] [Indexed: 12/16/2022] Open
Abstract
Penicillium digitatum is the main postharvest pathogen of citrus fruit and is responsible for important economic losses in spite of the massive use of fungicides. The fungal cell wall (CW) and its specific component chitin are potential targets for the development of new antifungal molecules. Among these are the antifungal peptides and proteins that specifically interact with fungal CW. Chitin is synthesized by a complex family of chitin synthases (Chs), classified into up to eight classes within three divisions. Previously, we obtained and characterized a mutant of P. digitatum in the class VII gene (ΔchsVII), which contains a short myosin motor-like domain (MMD). In this report, we extend our previous studies to the characterization of mutants in chsII and in the gene coding for the other MMD-Chs (chsV), and study the role of chitin synthases in the sensitivity of P. digitatum to the self-antifungal protein AfpB, and to AfpA obtained from P. expansum. The ΔchsII mutant showed no significant phenotypic and virulence differences with the wild type strain, except in the production and morphology of the conidia. In contrast, mutants in chsV showed a more dramatic phenotype than the previous ΔchsVII, with reduced growth and conidial production, increased chitin content, changes in mycelial morphology and a decrease in virulence to citrus fruit. Mutants in chsVII were specifically more tolerant than the wild type to nikkomycin Z, an antifungal inhibitor of chitin biosynthesis. Treatment of P. digitatum with its own antifungal protein AfpB resulted in an overall reduction in the expression of the chitin synthase genes. The mutants corresponding to MMD chitin synthases exhibited differential sensitivity to the antifungal proteins AfpA and AfpB, ΔchsVII being more susceptible than its parental strain and ΔchsV being slightly more tolerant despite its reduced growth in liquid broth. Taking these results together, we conclude that the MMD-containing chitin synthases affect cell wall integrity and sensitivity to antifungal proteins in P. digitatum.
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Affiliation(s)
- Mónica Gandía
- Department of Biotechnology, Instituto de Agroquímica y Tecnología de Alimentos, Consejo Superior de Investigaciones Científicas, Valencia, Spain
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11
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Takeshita N. Control of Actin and Calcium for Chitin Synthase Delivery to the Hyphal Tip of Aspergillus. Curr Top Microbiol Immunol 2019; 425:113-129. [PMID: 31974757 DOI: 10.1007/82_2019_193] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Filamentous fungi are covered by a cell wall consisting mainly of chitin and glucan. The synthesis of chitin, a β-1,4-linked homopolymer of N-acetylglucosamine, is essential for hyphal morphogenesis. Fungal chitin synthases are integral membrane proteins that have been classified into seven classes. ChsB, a class III chitin synthase, is known to play a key role in hyphal tip growth and has been used here as a model to understand the cell biology of cell wall biosynthesis in Aspergillus nidulans. Chitin synthases are transported on secretory vesicles to the plasma membrane for new cell wall synthesis. Super-resolution localization imaging as a powerful biophysical approach indicated dynamics of the Spitzenkörper where spatiotemporally regulated exocytosis and cell extension, whereas high-speed pulse-chase imaging has revealed ChsB transport mechanism mediated by kinesin-1 and myosin-5. In addition, live imaging analysis showed correlations among intracellular Ca2+ levels, actin assembly, and exocytosis in growing hyphal tips. This suggests that pulsed Ca2+ influxes coordinate the temporal control of actin assembly and exocytosis, which results in stepwise cell extension. It is getting clear that turgor pressure and cell wall pressure are involved in the activation of Ca2+ channels for Ca2+ oscillation and cell extension. Here the cell wall synthesis and tip growth meet again.
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Affiliation(s)
- Norio Takeshita
- Microbiology Research Center for Sustainability (MiCS), Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan.
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12
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Mitic M, Berry D, Brasell E, Green K, Young CA, Saikia S, Rakonjac J, Scott B. Disruption of calcineurin catalytic subunit (cnaA) in Epichloë festucae induces symbiotic defects and intrahyphal hyphae formation. MOLECULAR PLANT PATHOLOGY 2018; 19:1414-1426. [PMID: 28990722 PMCID: PMC6638138 DOI: 10.1111/mpp.12624] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 10/03/2017] [Accepted: 10/04/2017] [Indexed: 05/30/2023]
Abstract
Calcineurin is a conserved calcium/calmodulin-dependent protein phosphatase, consisting of a catalytic subunit A and a regulatory subunit B, which is involved in calcium-dependent signalling and regulation of various important cellular processes. In this study, we functionally characterized the catalytic subunit A (CnaA) of the endophytic fungus Epichloë festucae which forms a symbiotic association with the grass host Lolium perenne. We deleted the CnaA-encoding gene cnaA in E. festucae and examined its role in hyphal growth, cell wall integrity and symbiosis. This ΔcnaA strain had a severe growth defect with loss of radial growth and hyper-branched hyphae. Transmission electron microscopy and confocal microscopy analysis of the mutant revealed cell wall defects, aberrant septation and the formation of intrahyphal hyphae, both in culture and in planta. The mutant strain also showed a reduced infection rate in planta. The fluorescence of mutant hyphae stained with WGA-AF488 was reduced, indicating reduced chitin accessibility. Together, these results show that E. festucae CnaA is required for fungal growth, maintaining cell wall integrity and host colonization.
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Affiliation(s)
- Milena Mitic
- Institute of Fundamental Sciences, Massey UniversityPalmerston North4442New Zealand
- BioProtection Research Centre, Massey UniversityPalmerston North4442New Zealand
| | - Daniel Berry
- Institute of Fundamental Sciences, Massey UniversityPalmerston North4442New Zealand
| | - Emma Brasell
- Institute of Fundamental Sciences, Massey UniversityPalmerston North4442New Zealand
| | - Kimberly Green
- Institute of Fundamental Sciences, Massey UniversityPalmerston North4442New Zealand
- BioProtection Research Centre, Massey UniversityPalmerston North4442New Zealand
| | | | - Sanjay Saikia
- Institute of Fundamental Sciences, Massey UniversityPalmerston North4442New Zealand
| | - Jasna Rakonjac
- Institute of Fundamental Sciences, Massey UniversityPalmerston North4442New Zealand
| | - Barry Scott
- Institute of Fundamental Sciences, Massey UniversityPalmerston North4442New Zealand
- BioProtection Research Centre, Massey UniversityPalmerston North4442New Zealand
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13
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Guerriero G, Silvestrini L, Legay S, Maixner F, Sulyok M, Hausman JF, Strauss J. Deletion of the celA gene in Aspergillus nidulans triggers overexpression of secondary metabolite biosynthetic genes. Sci Rep 2017; 7:5978. [PMID: 28729615 PMCID: PMC5519750 DOI: 10.1038/s41598-017-05920-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 06/06/2017] [Indexed: 11/30/2022] Open
Abstract
Although much progress has been made in the study of cell wall biosynthetic genes in the model filamentous fungus Aspergillus nidulans, there are still targets awaiting characterization. An example is the gene celA (ANIA_08444) encoding a putative mixed linkage glucan synthase. To characterize the role of celA, we deleted it in A. nidulans, analyzed the phenotype of the mycelium and performed RNA-Seq. The strain shows a very strong phenotype, namely “balloons” along the hyphae and aberrant conidiophores, as well as an altered susceptibility to cell wall drugs. These data suggest a potential role of the gene in cell wall-related processes. The Gene Ontology term Enrichment analysis shows increased expression of secondary metabolite biosynthetic genes (sterigmatocystin in particular) in the deleted strain. Our results show that the deletion of celA triggers a strong phenotype reminiscent of cell wall-related aberrations and the upregulation of some secondary metabolite gene clusters in A. nidulans.
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Affiliation(s)
- Gea Guerriero
- Luxembourg Institute of Science and Technology (LIST), Environmental Research and Innovation (ERIN) Department, Esch/Alzette, L-4362, Luxembourg.
| | - Lucia Silvestrini
- University of Natural Resources and Life Sciences Vienna (BOKU), Department of Applied Genetics and Cell Biology, Fungal Genetics and Genomics Unit, BOKU Campus, Tulln/Donau, A-3430, Austria
| | - Sylvain Legay
- Luxembourg Institute of Science and Technology (LIST), Environmental Research and Innovation (ERIN) Department, Esch/Alzette, L-4362, Luxembourg
| | - Frank Maixner
- European Academy of Bozen/Bolzano (EURAC), Institute for Mummies and the Iceman, Bolzano, 39100, Italy
| | - Michael Sulyok
- University of Natural Resources and Life Sciences Vienna (BOKU), Department for Agrobiotechnology (IFA-Tulln), A-3430, Tulln, Austria
| | - Jean-Francois Hausman
- Luxembourg Institute of Science and Technology (LIST), Environmental Research and Innovation (ERIN) Department, Esch/Alzette, L-4362, Luxembourg
| | - Joseph Strauss
- University of Natural Resources and Life Sciences Vienna (BOKU), Department of Applied Genetics and Cell Biology, Fungal Genetics and Genomics Unit, BOKU Campus, Tulln/Donau, A-3430, Austria.
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14
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Abstract
Filamentous fungi are a large and ancient clade of microorganisms that occupy a broad range of ecological niches. The success of filamentous fungi is largely due to their elongate hypha, a chain of cells, separated from each other by septa. Hyphae grow by polarized exocytosis at the apex, which allows the fungus to overcome long distances and invade many substrates, including soils and host tissues. Hyphal tip growth is initiated by establishment of a growth site and the subsequent maintenance of the growth axis, with transport of growth supplies, including membranes and proteins, delivered by motors along the cytoskeleton to the hyphal apex. Among the enzymes delivered are cell wall synthases that are exocytosed for local synthesis of the extracellular cell wall. Exocytosis is opposed by endocytic uptake of soluble and membrane-bound material into the cell. The first intracellular compartment in the endocytic pathway is the early endosomes, which emerge to perform essential additional functions as spatial organizers of the hyphal cell. Individual compartments within septated hyphae can communicate with each other via septal pores, which allow passage of cytoplasm or organelles to help differentiation within the mycelium. This article introduces the reader to more detailed aspects of hyphal growth in fungi.
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15
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The chitin synthase FgChs2 and other FgChss co-regulate vegetative development and virulence in F. graminearum. Sci Rep 2016; 6:34975. [PMID: 27725723 PMCID: PMC5057161 DOI: 10.1038/srep34975] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 09/21/2016] [Indexed: 11/24/2022] Open
Abstract
Fusarium graminearum contains eight chitin synthase (Chs) genes belonging to seven classes. Previous studies have found that deletion of FgChs3b is lethal to F. graminearum, and deletion of FgChs1, FgChs2, FgChs7 and FgChs5 caused diverse defects in chitin content, mycelial growth, conidiation, virulence or stress responses. However, little is known about the functional relationships among these FgChss. In this study, FgChs2 deletion mutant ΔFgChs2 exhibited reduced mycelial growth and virulence as reported previously. In addition, we found that the mutant produced thickened and “wavy” septa. Quantitative real-time PCR (qRT-PCR) assays showed that the expression levels of FgChs1, FgChs3a, FgChs4, FgChs7, FgChs5 and FgChs6 in ΔFgChs2 were significantly higher than those in the wild type. Therefore, we generated six double deletion mutants of FgChs2 and each of the above six FgChss, and found that FgChs2 shares a function with FgChs1 in regulating mycelial growth, and co-regulates conidiation with FgChs1, FgChs4, FgChs7 and FgChs5. Furthermore, FgChs2 and other six FgChss have overlapped functions in virulence, DON production and septum formation. Taken together, these results indicate that although each chitin synthase of F. graminearum plays certain roles, FgChss may co-regualte various cellular processes in F. graminearum.
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16
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Hoshi HO, Zheng L, Ohta A, Horiuchi H. A Wiskott-Aldrich syndrome protein is involved in endocytosis in Aspergillus nidulans. Biosci Biotechnol Biochem 2016; 80:1802-12. [PMID: 26927610 DOI: 10.1080/09168451.2016.1148580] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Endocytosis is vital for hyphal tip growth in filamentous fungi and is involved in the tip localization of various membrane proteins. To investigate the function of a Wiskott-Aldrich syndrome protein (WASP) in endocytosis of filamentous fungi, we identified a WASP ortholog-encoding gene, wspA, in Aspergillus nidulans and characterized it. The wspA product, WspA, localized to the tips of germ tubes during germination and actin rings in the subapical regions of mature hyphae. wspA is essential for the growth and functioned in the polarity establishment and maintenance during germination of conidia. We also investigated its function in endocytosis and revealed that endocytosis of SynA, a synaptobrevin ortholog that is known to be endocytosed at the subapical regions of hyphal tips in A. nidulans, did not occur when wspA expression was repressed. These results suggest that WspA plays roles in endocytosis at hyphal tips and polarity establishment during germination.
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Affiliation(s)
- Hiro-Omi Hoshi
- a Department of Biotechnology , The University of Tokyo , Tokyo , Japan
| | - Lu Zheng
- a Department of Biotechnology , The University of Tokyo , Tokyo , Japan
| | - Akinori Ohta
- a Department of Biotechnology , The University of Tokyo , Tokyo , Japan
| | - Hiroyuki Horiuchi
- a Department of Biotechnology , The University of Tokyo , Tokyo , Japan
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17
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Zhang YZ, Chen Q, Liu CH, Liu YB, Yi P, Niu KX, Wang YQ, Wang AQ, Yu HY, Pu ZE, Jiang QT, Wei YM, Qi PF, Zheng YL. Chitin synthase gene FgCHS8 affects virulence and fungal cell wall sensitivity to environmental stress in Fusarium graminearum. Fungal Biol 2016; 120:764-74. [PMID: 27109372 DOI: 10.1016/j.funbio.2016.02.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 01/30/2016] [Accepted: 02/05/2016] [Indexed: 11/18/2022]
Abstract
Fusarium graminearum is the major causal agent of Fusarium head blight (FHB) of wheat and barley and is considered to be one of the most devastating plant diseases worldwide. Chitin is a critical component of the fungal cell wall and is polymerized from UDP-N-acetyl-alpha-D-glucosamine by chitin synthase. We characterized FgCHS8, a new class of the chitin synthase gene in F. graminearum. Disruption of FgCHS8 resulted in reduced accumulation of chitin, decreased chitin synthase activity, and had no effect on conidia growth when compared with the wild-type isolate. ΔFgCHS8 had a growth rate comparable to that of the wild-type isolate in vitro. However, ΔFgCHS8 had reduced growth when grown on agar supplemented with either 0.025% SDS or 0.9 mM salicylic acid. ΔFgCHS8 produced significantly less deoxynivalenol and exhibited reduced pathogenicity in wheat spikes. Re-introduction of a functional FgCHS8 gene into the ΔFgCHS8 mutant strain restored the wild-type phenotypes. Fluorescence microscopy revealed that FgCHS8 protein was initially expressed in the septa zone, and then gradually distributed over the entire cellular membrane, indicating that FgCHS8 was required for cell wall development. Our results demonstrated that FgCHS8 is important for cell wall sensitivity to environmental stress factors and deoxynivalenol production in F. graminearum.
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Affiliation(s)
- Ya-Zhou Zhang
- Triticeae Research Institute, Sichuan Agricultural University, Chengdu, Sichuan 611130, China.
| | - Qing Chen
- Triticeae Research Institute, Sichuan Agricultural University, Chengdu, Sichuan 611130, China.
| | - Cai-Hong Liu
- Agronomy College, Sichuan Agricultural University, Chengdu, Sichuan 611130, China.
| | - Yu-Bin Liu
- Agricultural Science Research Institute, Xichang, Sichuan 615000, China.
| | - Pan Yi
- Agronomy College, Sichuan Agricultural University, Chengdu, Sichuan 611130, China.
| | - Ke-Xin Niu
- Agronomy College, Sichuan Agricultural University, Chengdu, Sichuan 611130, China.
| | - Yan-Qing Wang
- Agronomy College, Sichuan Agricultural University, Chengdu, Sichuan 611130, China.
| | - An-Qi Wang
- Agronomy College, Sichuan Agricultural University, Chengdu, Sichuan 611130, China.
| | - Hai-Yue Yu
- Agronomy College, Sichuan Agricultural University, Chengdu, Sichuan 611130, China.
| | - Zhi-En Pu
- Agronomy College, Sichuan Agricultural University, Chengdu, Sichuan 611130, China.
| | - Qian-Tao Jiang
- Triticeae Research Institute, Sichuan Agricultural University, Chengdu, Sichuan 611130, China.
| | - Yu-Ming Wei
- Triticeae Research Institute, Sichuan Agricultural University, Chengdu, Sichuan 611130, China.
| | - Peng-Fei Qi
- Triticeae Research Institute, Sichuan Agricultural University, Chengdu, Sichuan 611130, China.
| | - You-Liang Zheng
- Triticeae Research Institute, Sichuan Agricultural University, Chengdu, Sichuan 611130, China.
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18
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Juvvadi PR, Steinbach WJ. Calcineurin Orchestrates Hyphal Growth, Septation, Drug Resistance and Pathogenesis of Aspergillus fumigatus: Where Do We Go from Here? Pathogens 2015; 4:883-93. [PMID: 26694470 PMCID: PMC4693169 DOI: 10.3390/pathogens4040883] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 12/07/2015] [Accepted: 12/11/2015] [Indexed: 12/27/2022] Open
Abstract
Studies on fungal pathogens belonging to the ascomycota phylum are critical given the ubiquity and frequency with which these fungi cause infections in humans. Among these species, Aspergillus fumigatus causes invasive aspergillosis, a leading cause of death in immunocompromised patients. Fundamental to A. fumigatus pathogenesis is hyphal growth. However, the precise mechanisms underlying hyphal growth and virulence are poorly understood. Over the past 10 years, our research towards the identification of molecular targets responsible for hyphal growth, drug resistance and virulence led to the elucidation of calcineurin as a key signaling molecule governing these processes. In this review, we summarize our salient findings on the significance of calcineurin for hyphal growth and septation in A. fumigatus and propose future perspectives on exploiting this pathway for designing new fungal-specific therapeutics.
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Affiliation(s)
- Praveen R Juvvadi
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Duke University Medical Center, Durham, NC 27710, USA.
| | - William J Steinbach
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Duke University Medical Center, Durham, NC 27710, USA.
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA.
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19
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Langner T, Göhre V. Fungal chitinases: function, regulation, and potential roles in plant/pathogen interactions. Curr Genet 2015; 62:243-54. [PMID: 26527115 DOI: 10.1007/s00294-015-0530-x] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 10/20/2015] [Accepted: 10/22/2015] [Indexed: 12/13/2022]
Abstract
In the past decades our knowledge about fungal cell wall architecture increased tremendously and led to the identification of many enzymes involved in polysaccharide synthesis and remodeling, which are also of biotechnological interest. Fungal cell walls play an important role in conferring mechanic stability during cell division and polar growth. Additionally, in phytopathogenic fungi the cell wall is the first structure that gets into intimate contact with the host plant. A major constituent of fungal cell walls is chitin, a homopolymer of N-acetylglucosamine units. To ensure plasticity, polymeric chitin needs continuous remodeling which is maintained by chitinolytic enzymes, including lytic polysaccharide monooxygenases N-acetylglucosaminidases, and chitinases. Depending on the species and lifestyle of fungi, there is great variation in the number of encoded chitinases and their function. Chitinases can have housekeeping function in plasticizing the cell wall or can act more specifically during cell separation, nutritional chitin acquisition, or competitive interaction with other fungi. Although chitinase research made huge progress in the last decades, our knowledge about their role in phytopathogenic fungi is still scarce. Recent findings in the dimorphic basidiomycete Ustilago maydis show that chitinases play different physiological functions throughout the life cycle and raise questions about their role during plant-fungus interactions. In this work we summarize these functions, mechanisms of chitinase regulation and their putative role during pathogen/host interactions.
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Affiliation(s)
- Thorsten Langner
- Institute for Microbiology, Heinrich-Heine University Düsseldorf, Universitätsstr. 1, 40225, Düsseldorf, Germany
| | - Vera Göhre
- Institute for Microbiology, Heinrich-Heine University Düsseldorf, Universitätsstr. 1, 40225, Düsseldorf, Germany.
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20
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Park HS, Man Yu Y, Lee MK, Jae Maeng P, Chang Kim S, Yu JH. Velvet-mediated repression of β-glucan synthesis in Aspergillus nidulans spores. Sci Rep 2015; 5:10199. [PMID: 25960370 PMCID: PMC4426670 DOI: 10.1038/srep10199] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 04/02/2015] [Indexed: 12/19/2022] Open
Abstract
Beta-glucans are a heterologous group of fibrous glucose polymers that are a major constituent of cell walls in Ascomycetes and Basidiomycetes fungi. Synthesis of β (1,3)- and (1,6)-glucans is coordinated with fungal cell growth and development, thus, is under tight genetic regulation. Here, we report that β-glucan synthesis in both asexual and sexual spores is turned off by the NF-kB like fungal regulators VosA and VelB in Aspergillus nidulans. Our genetic and genomic analyses have revealed that both VosA and VelB are necessary for proper down-regulation of cell wall biosynthetic genes including those associated with β-glucan synthesis in both types of spores. The deletion of vosA or velB results in elevated accumulation of β-glucan in asexual spores. Double mutant analyses indicate that VosA and VelB play an inter-dependent role in repressing β-glucan synthesis in asexual spores. In vivo chromatin immuno-precipitation analysis shows that both VelB and VosA bind to the promoter region of the β-glucan synthase gene fksA in asexual spores. Similarly, VosA is required for proper repression of β-glucan synthesis in sexual spores. In summary, the VosA-VelB hetero-complex is a key regulatory unit tightly controlling proper levels of β-glucan synthesis in asexual and sexual spores.
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Affiliation(s)
- Hee-Soo Park
- Department of Bacteriology, University of Wisconsin, Madison, WI, USA
| | - Yeong Man Yu
- Department of Microbiology and Molecular Biology, Chungnam National University, Daejeon, Republic of Korea
| | - Mi-Kyung Lee
- Department of Bacteriology, University of Wisconsin, Madison, WI, USA
| | - Pil Jae Maeng
- Department of Microbiology and Molecular Biology, Chungnam National University, Daejeon, Republic of Korea
| | - Sun Chang Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Dae-Jon, Republic of Korea
| | - Jae-Hyuk Yu
- Department of Bacteriology, University of Wisconsin, Madison, WI, USA
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21
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Transcriptional control of fungal cell cycle and cellular events by Fkh2, a forkhead transcription factor in an insect pathogen. Sci Rep 2015; 5:10108. [PMID: 25955538 PMCID: PMC4424799 DOI: 10.1038/srep10108] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Accepted: 03/30/2015] [Indexed: 01/18/2023] Open
Abstract
Transcriptional control of the cell cycle by forkhead (Fkh) transcription factors is likely associated with fungal adaptation to host and environment. Here we show that Fkh2, an ortholog of yeast Fkh1/2, orchestrates cell cycle and many cellular events of Beauveria bassiana, a filamentous fungal insect pathogen. Deletion of Fkh2 in B. bassiana resulted in dramatic down-regulation of the cyclin-B gene cluster and hence altered cell cycle (longer G2/M and S, but shorter G0/G1, phases) in unicellular blastospores. Consequently, ΔFkh2 produced twice as many, but smaller, blastospores than wild-type under submerged conditions, and formed denser septa and shorter/broader cells in aberrantly branched hyphae. In these hyphae, clustered genes required for septation and conidiation were remarkedly up-regulated, followed by higher yield and slower germination of aerial conidia. Moreover, ΔFkh2 displayed attenuated virulence and decreased tolerance to chemical and environmental stresses, accompanied with altered transcripts and activities of phenotype-influencing proteins or enzymes. All the changes in ΔFkh2 were restored by Fkh2 complementation. All together, Fkh2-dependent transcriptional control is vital for the adaptation of B. bassiana to diverse habitats of host insects and hence contributes to its biological control potential against arthropod pests.
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22
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Takeshita N, Wernet V, Tsuizaki M, Grün N, Hoshi HO, Ohta A, Fischer R, Horiuchi H. Transportation of Aspergillus nidulans Class III and V Chitin Synthases to the Hyphal Tips Depends on Conventional Kinesin. PLoS One 2015; 10:e0125937. [PMID: 25955346 PMCID: PMC4425547 DOI: 10.1371/journal.pone.0125937] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 03/21/2015] [Indexed: 12/02/2022] Open
Abstract
Cell wall formation and maintenance are crucial for hyphal morphogenesis. In many filamentous fungi, chitin is one of the main structural components of the cell wall. Aspergillus nidulans ChsB, a chitin synthase, and CsmA, a chitin synthase with a myosin motor-like domain (MMD) at its N-terminus, both localize predominantly at the hyphal tip regions and at forming septa. ChsB and CsmA play crucial roles in polarized hyphal growth in A. nidulans. In this study, we investigated the mechanism by which CsmA and ChsB accumulate at the hyphal tip in living hyphae. Deletion of kinA, a gene encoding conventional kinesin (kinesin-1), impaired the localization of GFP-CsmA and GFP-ChsB at the hyphal tips. The transport frequency of GFP-CsmA and GFP-ChsB in both anterograde and retrograde direction appeared lower in the kinA-deletion strain compared to wild type, although the velocities of the movements were comparable. Co-localization of GFP-ChsB and GFP-CsmA with mRFP1-KinArigor, a KinA mutant that binds to microtubules but does not move along them, was observed in the posterior of the hyphal tip regions. KinA co-immunoprecipitated with ChsB and CsmA. Co-localization and association of CsmA with KinA did not depend on the MMD. These findings indicate that ChsB and CsmA are transported along microtubules to the subapical region by KinA.
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Affiliation(s)
- Norio Takeshita
- Department of Microbiology, Institute for Applied Biosciences, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Valentin Wernet
- Department of Microbiology, Institute for Applied Biosciences, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Makusu Tsuizaki
- Department of Biotechnology, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Nathalie Grün
- Department of Microbiology, Institute for Applied Biosciences, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Hiro-omi Hoshi
- Department of Biotechnology, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Akinori Ohta
- Department of Biotechnology, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Reinhard Fischer
- Department of Microbiology, Institute for Applied Biosciences, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Hiroyuki Horiuchi
- Department of Biotechnology, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
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23
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Sánchez-Vallet A, Mesters JR, Thomma BP. The battle for chitin recognition in plant-microbe interactions. FEMS Microbiol Rev 2015; 39:171-83. [DOI: 10.1093/femsre/fuu003] [Citation(s) in RCA: 171] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
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24
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Katayama T, Ohta A, Horiuchi H. Protein kinase C regulates the expression of cell wall-related genes in RlmA-dependent and independent manners in Aspergillus nidulans. Biosci Biotechnol Biochem 2015; 79:321-30. [DOI: 10.1080/09168451.2014.973365] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Abstract
A protein kinase C of Aspergillus nidulans, PkcA, is required for cell wall integrity (CWI) and is considered a major component of the regulating pathway. To investigate whether PkcA regulates the transcription of cell wall-related genes, we constructed strains expressing pkcA(R429A) that encodes an activated form of PkcA. The mRNA levels of most chitin synthase genes and an α-glucan synthase gene, agsB, were increased when pkcA(R429A) expression was induced. These mRNA increases were not observed or were only partially observed, in a deletion mutant of rlmA, an ortholog of RLM1 that encodes a transcription factor in the CWI pathway in Saccharomyces cerevisiae. In addition, in a pkcA temperature-sensitive mutant under heat stress, the mRNA levels of some chitin synthase genes and agsB did not increase. These results suggest that PkcA is involved in CWI maintenance through the transcriptional regulation of cell wall-related genes.
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Affiliation(s)
- Takuya Katayama
- Department of Biotechnology, The University of Tokyo, Tokyo, Japan
| | - Akinori Ohta
- Department of Biotechnology, The University of Tokyo, Tokyo, Japan
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25
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Muszkieta L, Aimanianda V, Mellado E, Gribaldo S, Alcàzar-Fuoli L, Szewczyk E, Prevost MC, Latgé JP. Deciphering the role of the chitin synthase families 1 and 2 in thein vivoandin vitrogrowth ofAspergillus fumigatusby multiple gene targeting deletion. Cell Microbiol 2014; 16:1784-805. [DOI: 10.1111/cmi.12326] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Revised: 05/27/2014] [Accepted: 06/06/2014] [Indexed: 12/13/2022]
Affiliation(s)
| | | | - Emilia Mellado
- Mycology Reference Laboratory; Centro Nacional de Microbiologia; Instituto de Salud Carlos III; Madrid Spain
| | - Simonetta Gribaldo
- Unité de Biologie Moléculaire du gène chez les Extrêmophiles; Institut Pasteur; 75015 Paris France
| | - Laura Alcàzar-Fuoli
- Mycology Reference Laboratory; Centro Nacional de Microbiologia; Instituto de Salud Carlos III; Madrid Spain
| | - Edyta Szewczyk
- Department of Biological and Agricultural Engineering; University of California; Davis California USA
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26
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Qiu L, Wang JJ, Ying SH, Feng MG. Wee1 and Cdc25 control morphogenesis, virulence and multistress tolerance ofBeauveria bassianaby balancing cell cycle-required cyclin-dependent kinase 1 activity. Environ Microbiol 2014; 17:1119-33. [DOI: 10.1111/1462-2920.12530] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2014] [Revised: 05/31/2014] [Accepted: 05/31/2014] [Indexed: 01/08/2023]
Affiliation(s)
- Lei Qiu
- Institute of Microbiology; College of Life Sciences; Zhejiang University; Hangzhou Zhejiang 310058 China
| | - Juan-Juan Wang
- Institute of Microbiology; College of Life Sciences; Zhejiang University; Hangzhou Zhejiang 310058 China
| | - Sheng-Hua Ying
- Institute of Microbiology; College of Life Sciences; Zhejiang University; Hangzhou Zhejiang 310058 China
| | - Ming-Guang Feng
- Institute of Microbiology; College of Life Sciences; Zhejiang University; Hangzhou Zhejiang 310058 China
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Functional Differentiation of Chitin Synthases inYarrowia lipolytica. Biosci Biotechnol Biochem 2014; 77:1275-81. [DOI: 10.1271/bbb.130111] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Delgado-Álvarez DL, Bartnicki-García S, Seiler S, Mouriño-Pérez RR. Septum development in Neurospora crassa: the septal actomyosin tangle. PLoS One 2014; 9:e96744. [PMID: 24800890 PMCID: PMC4011870 DOI: 10.1371/journal.pone.0096744] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Accepted: 04/10/2014] [Indexed: 12/05/2022] Open
Abstract
Septum formation in Neurospora crassa was studied by fluorescent tagging of actin, myosin, tropomyosin, formin, fimbrin, BUD-4, and CHS-1. In chronological order, we recognized three septum development stages: 1) septal actomyosin tangle (SAT) assembly, 2) contractile actomyosin ring (CAR) formation, 3) CAR constriction together with plasma membrane ingrowth and cell wall construction. Septation began with the assembly of a conspicuous tangle of cortical actin cables (SAT) in the septation site >5 min before plasma membrane ingrowth. Tropomyosin and myosin were detected as components of the SAT from the outset. The SAT gradually condensed to form a proto-CAR that preceded CAR formation. During septum development, the contractile actomyosin ring remained associated with the advancing edge of the septum. Formin and BUD-4 were recruited during the transition from SAT to CAR and CHS-1 appeared two min before CAR constriction. Actin patches containing fimbrin were observed surrounding the ingrowing septum, an indication of endocytic activity. Although the trigger of SAT assembly remains unclear, the regularity of septation both in space and time gives us reason to believe that the initiation of the septation process is integrated with the mechanisms that control both the cell cycle and the overall growth of hyphae, despite the asynchronous nature of mitosis in N. crassa.
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Affiliation(s)
- Diego Luis Delgado-Álvarez
- Departamento de Microbiología, Centro de Educación Científica y de Educación Superior de Ensenada, Ensenada, B. C. México
| | - Salomón Bartnicki-García
- Departamento de Microbiología, Centro de Educación Científica y de Educación Superior de Ensenada, Ensenada, B. C. México
| | - Stephan Seiler
- Institute for Biology II – Molecular Plant Physiology, Albert-Ludwigs University Freiburg, Freiburg, Germany
- Freiburg Institute for Advanced Studies (FRIAS), Albert-Ludwigs University Freiburg, Freiburg, Germany
| | - Rosa Reyna Mouriño-Pérez
- Departamento de Microbiología, Centro de Educación Científica y de Educación Superior de Ensenada, Ensenada, B. C. México
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Guerriero G, Silvestrini L, Obersriebnig M, Salerno M, Pum D, Strauss J. Sensitivity of Aspergillus nidulans to the cellulose synthase inhibitor dichlobenil: insights from wall-related genes' expression and ultrastructural hyphal morphologies. PLoS One 2013; 8:e80038. [PMID: 24312197 PMCID: PMC3843659 DOI: 10.1371/journal.pone.0080038] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Accepted: 09/27/2013] [Indexed: 11/30/2022] Open
Abstract
The fungal cell wall constitutes an important target for the development of antifungal drugs, because of its central role in morphogenesis, development and determination of fungal-specific molecular features. Fungal walls are characterized by a network of interconnected glycoproteins and polysaccharides, namely α-, β-glucans and chitin. Cell walls promptly and dynamically respond to environmental stimuli by a signaling mechanism, which triggers, among other responses, modulations in wall biosynthetic genes’ expression. Despite the absence of cellulose in the wall of the model filamentous fungus Aspergillus nidulans, we found in this study that fungal growth, spore germination and morphology are affected by the addition of the cellulose synthase inhibitor dichlobenil. Expression analysis of selected genes putatively involved in cell wall biosynthesis, carried out at different time points of drug exposure (i.e. 0, 1, 3, 6 and 24 h), revealed increased expression for the putative mixed linkage β-1,3;1,4 glucan synthase celA together with the β-1,3-glucan synthase fksA and the Rho-related GTPase rhoA. We also compared these data with the response to Congo Red, a known plant/fungal drug affecting both chitin and cellulose biosynthesis. The two drugs exerted different effects at the cell wall level, as shown by gene expression analysis and the ultrastructural features observed through atomic force microscopy and scanning electron microscopy. Although the concentration of dichlobenil required to affect growth of A. nidulans is approximately 10-fold higher than that required to inhibit plant cellulose biosynthesis, our work for the first time demonstrates that a cellulose biosynthesis inhibitor affects fungal growth, changes fungal morphology and expression of genes connected to fungal cell wall biosynthesis.
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Affiliation(s)
- Gea Guerriero
- Department of Applied Genetics and Cell Biology, Fungal Genetics and Genomics Unit, University of Natural Resources and Life Sciences Vienna (BOKU), University and Research Center Campus Tulln-Technopol, Tulln/Donau, Austria
- * E-mail: (GG); (JS)
| | - Lucia Silvestrini
- Department of Applied Genetics and Cell Biology, Fungal Genetics and Genomics Unit, University of Natural Resources and Life Sciences Vienna (BOKU), University and Research Center Campus Tulln-Technopol, Tulln/Donau, Austria
| | - Michael Obersriebnig
- Institute of Wood Science and Technology, University of Natural Resources and Life Sciences Vienna (BOKU), University and Research Center Campus Tulln-Technopol, Tulln/Donau, Austria
| | - Marco Salerno
- Nanophysics Department, Istituto Italiano di Tecnologia, Genova, Italy
| | - Dietmar Pum
- Department of Nanobiotechnology, Institute for Biophysics, University of Natural Resources and Life Sciences Vienna (BOKU), Vienna, Austria
| | - Joseph Strauss
- Department of Applied Genetics and Cell Biology, Fungal Genetics and Genomics Unit, University of Natural Resources and Life Sciences Vienna (BOKU), University and Research Center Campus Tulln-Technopol, Tulln/Donau, Austria
- Health and Environment Department, Austrian Institute of Technology GmbH - AIT, University and Research Center Campus Tulln-Technopol, Tulln/Donau, Austria
- * E-mail: (GG); (JS)
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Walker LA, Lenardon MD, Preechasuth K, Munro CA, Gow NAR. Cell wall stress induces alternative fungal cytokinesis and septation strategies. J Cell Sci 2013; 126:2668-77. [PMID: 23606739 DOI: 10.1242/jcs.118885] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
In fungi, as with all walled organisms, cytokinesis followed by septation marks the end of the cell cycle and is essential for cell division and viability. For yeasts, the septal cross-wall comprises a ring and primary septal plate composed of chitin, and a secondary septum thickened with β(1,3)-glucan. In the human pathogen Candida albicans, chitin synthase enzyme Chs1 builds the primary septum that is surrounded by a chitin ring made by Chs3. Here we show that the lethal phenotype induced by repression of CHS1 was abrogated by stress-induced synthesis of alternative and novel septal types synthesized by other chitin synthase enzymes that have never before been implicated in septation. Chs2 and Chs8 formed a functional salvage septum, even in the absence of both Chs1 and Chs3. A second type of salvage septum formed by Chs2 in combination with Chs3 or Chs8 was proximally offset in the mother-bud neck. Chs3 alone or in combination with Chs8 formed a greatly thickened third type of salvage septum. Therefore, cell wall stress induced alternative forms of septation that rescued cell division in the absence of Chs1, demonstrating that fungi have previously unsuspected redundant strategies to enable septation and cell division to be maintained, even under potentially lethal environmental conditions.
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Affiliation(s)
- Louise A Walker
- Aberdeen Fungal Group, School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK
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Morcx S, Kunz C, Choquer M, Assie S, Blondet E, Simond-Côte E, Gajek K, Chapeland-Leclerc F, Expert D, Soulie MC. Disruption of Bcchs4, Bcchs6 or Bcchs7 chitin synthase genes in Botrytis cinerea and the essential role of class VI chitin synthase (Bcchs6). Fungal Genet Biol 2012; 52:1-8. [PMID: 23268147 DOI: 10.1016/j.fgb.2012.11.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Revised: 11/15/2012] [Accepted: 11/26/2012] [Indexed: 11/29/2022]
Abstract
Chitin synthases play critical roles in hyphal development and fungal pathogenicity. Previous studies on Botrytis cinerea, a model organism for necrotrophic pathogens, have shown that disruption of Bcchs1 and more particularly Bcchs3a genes have a drastic impact on virulence (Soulié et al., 2003, 2006). In this work, we investigate the role of other CHS including BcCHS4, BcCHS6 and BcCHS7 during the life cycle of B. cinerea. Single deletions of corresponding genes were carried out. Phenotypic analysis indicates that: (i) BcCHS4 enzyme is not essential for development and pathogenicity of the fungus; (ii) BcCHS7 is required for pathogenicity in a host dependant manner. For Bcchs6 gene disruption, we obtained only heterokaryotic strains. Indeed, sexual or asexual purification assays were unsuccessful. We concluded that class VI chitin synthase could be essential for B. cinerea and therefore BcCHS6 represents a valuable antifungal target.
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Affiliation(s)
- Serena Morcx
- UPMC Univ. Paris 06, UMR217, 75005 Paris, France
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Zhong G, Wei W, Guan Q, Ma Z, Wei H, Xu X, Zhang S, Lu L. Phosphoribosyl pyrophosphate synthetase, as a suppressor of thesepHmutation inAspergillus nidulans, is required for the proper timing of septation. Mol Microbiol 2012; 86:894-907. [DOI: 10.1111/mmi.12026] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/29/2012] [Indexed: 11/30/2022]
Affiliation(s)
- Guowei Zhong
- Jiangsu Key Laboratory for Microbes and Functional Genomics; Jiangsu Engineering and Technology Research Center for Microbiology; College of Life Sciences; Nanjing Normal University; Nanjing; 210046; China
| | - Wenfan Wei
- Jiangsu Key Laboratory for Microbes and Functional Genomics; Jiangsu Engineering and Technology Research Center for Microbiology; College of Life Sciences; Nanjing Normal University; Nanjing; 210046; China
| | - Qi Guan
- Jiangsu Key Laboratory for Microbes and Functional Genomics; Jiangsu Engineering and Technology Research Center for Microbiology; College of Life Sciences; Nanjing Normal University; Nanjing; 210046; China
| | - Zhaofei Ma
- Jiangsu Key Laboratory for Microbes and Functional Genomics; Jiangsu Engineering and Technology Research Center for Microbiology; College of Life Sciences; Nanjing Normal University; Nanjing; 210046; China
| | - Hua Wei
- Jiangsu Key Laboratory for Microbes and Functional Genomics; Jiangsu Engineering and Technology Research Center for Microbiology; College of Life Sciences; Nanjing Normal University; Nanjing; 210046; China
| | - Xushi Xu
- Jiangsu Key Laboratory for Microbes and Functional Genomics; Jiangsu Engineering and Technology Research Center for Microbiology; College of Life Sciences; Nanjing Normal University; Nanjing; 210046; China
| | - Shizhu Zhang
- Jiangsu Key Laboratory for Microbes and Functional Genomics; Jiangsu Engineering and Technology Research Center for Microbiology; College of Life Sciences; Nanjing Normal University; Nanjing; 210046; China
| | - Ling Lu
- Jiangsu Key Laboratory for Microbes and Functional Genomics; Jiangsu Engineering and Technology Research Center for Microbiology; College of Life Sciences; Nanjing Normal University; Nanjing; 210046; China
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Kong LA, Yang J, Li GT, Qi LL, Zhang YJ, Wang CF, Zhao WS, Xu JR, Peng YL. Different chitin synthase genes are required for various developmental and plant infection processes in the rice blast fungus Magnaporthe oryzae. PLoS Pathog 2012; 8:e1002526. [PMID: 22346755 PMCID: PMC3276572 DOI: 10.1371/journal.ppat.1002526] [Citation(s) in RCA: 146] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2011] [Accepted: 12/24/2011] [Indexed: 11/18/2022] Open
Abstract
Chitin is a major component of fungal cell wall and is synthesized by chitin synthases (Chs). Plant pathogenic fungi normally have multiple chitin synthase genes. To determine their roles in development and pathogenesis, we functionally characterized all seven CHS genes in Magnaporthe oryzae. Three of them, CHS1, CHS6, and CHS7, were found to be important for plant infection. While the chs6 mutant was non-pathogenic, the chs1 and chs7 mutants were significantly reduced in virulence. CHS1 plays a specific role in conidiogenesis, an essential step for natural infection cycle. Most of chs1 conidia had no septum and spore tip mucilage. The chs6 mutant was reduced in hyphal growth and conidiation. It failed to penetrate and grow invasively in plant cells. The two MMD-containing chitin synthase genes, CHS5 and CHS6, have a similar expression pattern. Although deletion of CHS5 had no detectable phenotype, the chs5 chs6 double mutant had more severe defects than the chs6 mutant, indicating that they may have overlapping functions in maintaining polarized growth in vegetative and invasive hyphae. Unlike the other CHS genes, CHS7 has a unique function in appressorium formation. Although it was blocked in appressorium formation by germ tubes on artificial hydrophobic surfaces, the chs7 mutant still produced melanized appressoria by hyphal tips or on plant surfaces, indicating that chitin synthase genes have distinct impacts on appressorium formation by hyphal tip and germ tube. The chs7 mutant also was defective in appressorium penetration and invasive growth. Overall, our results indicate that individual CHS genes play diverse roles in hyphal growth, conidiogenesis, appressorium development, and pathogenesis in M. oryzae, and provided potential new leads in the control of this devastating pathogen by targeting specific chitin synthases.
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Affiliation(s)
- Ling-An Kong
- State Key Laboratory of Agrobiotechnology and MOA Key Laboratory of Plant Pathology, China Agricultural University, Beijing, China
- Purdue-NWAFU Joint Research Center and State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
| | - Jun Yang
- State Key Laboratory of Agrobiotechnology and MOA Key Laboratory of Plant Pathology, China Agricultural University, Beijing, China
| | - Guo-Tian Li
- Purdue-NWAFU Joint Research Center and State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
| | - Lin-Lu Qi
- State Key Laboratory of Agrobiotechnology and MOA Key Laboratory of Plant Pathology, China Agricultural University, Beijing, China
| | - Yu-Jun Zhang
- State Key Laboratory of Agrobiotechnology and MOA Key Laboratory of Plant Pathology, China Agricultural University, Beijing, China
| | - Chen-Fang Wang
- College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
| | - Wen-Sheng Zhao
- State Key Laboratory of Agrobiotechnology and MOA Key Laboratory of Plant Pathology, China Agricultural University, Beijing, China
| | - Jin-Rong Xu
- Purdue-NWAFU Joint Research Center and State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
| | - You-Liang Peng
- State Key Laboratory of Agrobiotechnology and MOA Key Laboratory of Plant Pathology, China Agricultural University, Beijing, China
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Rogg LE, Fortwendel JR, Juvvadi PR, Steinbach WJ. Regulation of expression, activity and localization of fungal chitin synthases. Med Mycol 2012; 50:2-17. [PMID: 21526913 PMCID: PMC3660733 DOI: 10.3109/13693786.2011.577104] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The fungal cell wall represents an attractive target for pharmacologic inhibition, as many of the components are fungal-specific. Though targeted inhibition of β-glucan synthesis is effective treatment for certain fungal infections, the ability of the cell wall to dynamically compensate via the cell wall integrity pathway may limit overall efficacy. To date, chitin synthesis inhibitors have not been successfully deployed in the clinical setting. Fungal chitin synthesis is a complex and highly regulated process. Regulation of chitin synthesis occurs on multiple levels, thus targeting of these regulatory pathways may represent an exciting alternative approach. A variety of signaling pathways have been implicated in chitin synthase regulation, at both transcriptional and post-transcriptional levels. Recent research suggests that localization of chitin synthases likely represents a major regulatory mechanism. However, much of the regulatory machinery is not necessarily shared among different chitin synthases. Thus, an in-depth understanding of the precise roles of each protein in cell wall maintenance and repair will be essential to identifying the most likely therapeutic targets.
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Affiliation(s)
- Luise E. Rogg
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Duke University Medical Center, Durham NC, USA
| | - Jarrod R. Fortwendel
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Duke University Medical Center, Durham NC, USA
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham NC, USA
| | - Praveen R. Juvvadi
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Duke University Medical Center, Durham NC, USA
| | - William J. Steinbach
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Duke University Medical Center, Durham NC, USA
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham NC, USA
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Juvvadi PR, Fortwendel JR, Rogg LE, Burns KA, Randell SH, Steinbach WJ. Localization and activity of the calcineurin catalytic and regulatory subunit complex at the septum is essential for hyphal elongation and proper septation in Aspergillus fumigatus. Mol Microbiol 2011; 82:1235-59. [PMID: 22066998 DOI: 10.1111/j.1365-2958.2011.07886.x] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Calcineurin, a heterodimer composed of the catalytic (CnaA) and regulatory (CnaB) subunits, plays key roles in growth, virulence and stress responses of fungi. To investigate the contribution of CnaA and CnaB to hyphal growth and septation, ΔcnaB and ΔcnaAΔcnaB strains of Aspergillus fumigatus were constructed. CnaA colocalizes to the contractile actin ring early during septation and remains at the centre of the mature septum. While CnaB's septal localization is CnaA-dependent, CnaA's septal localization is CnaB-independent, but CnaB is required for CnaA's function at the septum. Catalytic null mutations in CnaA caused stunted growth despite septal localization of the calcineurin complex, indicating the requirement of calcineurin activity at the septum. Compared to the ΔcnaA and ΔcnaB strains, the ΔcnaAΔcnaB strain displayed more defective growth and aberrant septation. While three Ca(2+) -binding motifs in CnaB were sufficient for its association with CnaA at the septum, the amino-terminal arginine-rich domains (16-RRRR-19 and 44-RLRKR-48) are dispensable for septal localization, yet required for complete functionality. Mutation of the 51-KLDK-54 motif in CnaB causes its mislocalization from the septum to the nucleus, suggesting it is a nuclear export signal sequence. These findings confirm a cooperative role for the calcineurin complex in regulating hyphal growth and septation.
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Affiliation(s)
- Praveen Rao Juvvadi
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Duke University Medical Center, Durham, NC, USA
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Characterization of a mutant strain of a filamentous fungus Cladosporium phlei for the mass production of the secondary metabolite phleichrome. J Microbiol 2011; 49:680-3. [PMID: 21887655 DOI: 10.1007/s12275-011-1022-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Accepted: 04/11/2011] [Indexed: 10/17/2022]
Abstract
UV-mutagenesis was performed to obtain mutant strains that demonstrate altered production of phleichrome, a secondary metabolite of Cladosporium phlei. Among fifty mutants selected, based on the increased area and intensity of the purple pigment surrounding the colonies, the strain M0035 showed the highest production of phleichrome, more than seven fold over wild type. Plate cultures of the M0035 strain resulted in a total of 592 mg phleichrome consisting of 146 mg and 446 mg from the mycelia and agar media, respectively. The M0035 strain displayed a growth rate and a mycelial mass comparable to the parental strain but had significantly reduced asexual sporulation.
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Hayakawa Y, Ishikawa E, Shoji J, Nakano H, Kitamoto K. Septum‐directed secretion in the filamentous fungus
Aspergillus oryzae. Mol Microbiol 2011; 81:40-55. [DOI: 10.1111/j.1365-2958.2011.07700.x] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Yugo Hayakawa
- Department of Biotechnology, The University of Tokyo, 1‐1‐1 Yayoi, Bunkyo‐ku, Tokyo 113‐8657, Japan
| | - Eri Ishikawa
- Department of Biotechnology, The University of Tokyo, 1‐1‐1 Yayoi, Bunkyo‐ku, Tokyo 113‐8657, Japan
| | | | - Hiroyuki Nakano
- Department of Biotechnology, The University of Tokyo, 1‐1‐1 Yayoi, Bunkyo‐ku, Tokyo 113‐8657, Japan
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Chen S, Song Y, Cao J, Wang G, Wei H, Xu X, Lu L. Localization and function of calmodulin in live-cells of Aspergillus nidulans. Fungal Genet Biol 2010; 47:268-78. [DOI: 10.1016/j.fgb.2009.12.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2009] [Revised: 10/29/2009] [Accepted: 12/17/2009] [Indexed: 10/20/2022]
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Disruption of the chitin synthase gene CHS1 from Fusarium asiaticum results in an altered structure of cell walls and reduced virulence. Fungal Genet Biol 2010; 47:205-15. [DOI: 10.1016/j.fgb.2009.11.003] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2008] [Revised: 11/10/2009] [Accepted: 11/11/2009] [Indexed: 11/22/2022]
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Gibberella zeae chitin synthase genes, GzCHS5 and GzCHS7, are required for hyphal growth, perithecia formation, and pathogenicity. Curr Genet 2009; 55:449-59. [DOI: 10.1007/s00294-009-0258-6] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2009] [Revised: 06/06/2009] [Accepted: 06/08/2009] [Indexed: 10/20/2022]
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Class III chitin synthase ChsB of Aspergillus nidulans localizes at the sites of polarized cell wall synthesis and is required for conidial development. EUKARYOTIC CELL 2009; 8:945-56. [PMID: 19411617 DOI: 10.1128/ec.00326-08] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Class III chitin synthases play important roles in tip growth and conidiation in many filamentous fungi. However, little is known about their functions in those processes. To address these issues, we characterized the deletion mutant of a class III chitin synthase-encoding gene of Aspergillus nidulans, chsB, and investigated ChsB localization in the hyphae and conidiophores. Multilayered cell walls and intrahyphal hyphae were observed in the hyphae of the chsB deletion mutant, and wavy septa were also occasionally observed. ChsB tagged with FLAG or enhanced green fluorescent protein (EGFP) localized mainly at the tips of germ tubes, hyphal tips, and forming septa during hyphal growth. EGFP-ChsB predominantly localized at polarized growth sites and between vesicles and metulae, between metulae and phialides, and between phalides and conidia in asexual development. These results strongly suggest that ChsB functions in the formation of normal cell walls of hyphae, as well as in conidiophore and conidia development in A. nidulans.
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45
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Horiuchi H. Functional diversity of chitin synthases ofAspergillus nidulansin hyphal growth, conidiophore development and septum formation. Med Mycol 2009; 47 Suppl 1:S47-52. [DOI: 10.1080/13693780802213332] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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46
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Calcineurin localizes to the hyphal septum in Aspergillus fumigatus: implications for septum formation and conidiophore development. EUKARYOTIC CELL 2008; 7:1606-10. [PMID: 18606829 DOI: 10.1128/ec.00200-08] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A functional calcineurin A fusion to enhanced green fluorescent protein (EGFP), CnaA-EGFP, was expressed in the Aspergillus fumigatus DeltacnaA mutant. CnaA-EGFP localized in actively growing hyphal tips, at the septa, and at junctions between the vesicle and phialides in an actin-dependent manner. This is the first study to implicate calcineurin in septum formation and conidiophore development of a filamentous fungus.
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47
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Advances in understanding hyphal morphogenesis: Ontogeny, phylogeny and cellular localization of chitin synthases. FUNGAL BIOL REV 2008. [DOI: 10.1016/j.fbr.2008.05.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Yamazaki H, Tanaka A, Kaneko JI, Ohta A, Horiuchi H. Aspergillus nidulans ChiA is a glycosylphosphatidylinositol (GPI)-anchored chitinase specifically localized at polarized growth sites. Fungal Genet Biol 2008; 45:963-72. [PMID: 18420434 DOI: 10.1016/j.fgb.2008.02.008] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2007] [Revised: 02/25/2008] [Accepted: 02/25/2008] [Indexed: 11/26/2022]
Abstract
It is believed that chitinases play important physiological roles in filamentous fungi since chitin is one of the major cell wall components in these organisms. In this paper we investigated a chitinase gene, chiA, of Aspergillus nidulans and found that the gene product of chiA consists of a signal sequence, a region including chitinase consensus motifs, a Ser/Thr/Pro-rich region and a glycosylphosphatidylinositol (GPI)-anchor attachment motif. Phosphatidylinositol-specific phospholipase C treatment of the fusion protein of ChiA and enhanced green fluorescent protein (EGFP)-ChiA-EGFP-caused a change in its hydrophobicity, indicating that ChiA is a GPI-anchored protein. ChiA-EGFP localized at the germ tubes of conidia, at hyphal branching sites and hyphal tips. chiA expression was specifically high during conidia germination and in the marginal growth regions of colonies. These results suggest that ChiA functions as a GPI-anchored chitinase at the sites where cell wall remodeling and/or cell wall maturation actively take place.
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Affiliation(s)
- Harutake Yamazaki
- Department of Biotechnology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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ChsVb, a class VII chitin synthase involved in septation, is critical for pathogenicity in Fusarium oxysporum. EUKARYOTIC CELL 2007; 7:112-21. [PMID: 17993572 DOI: 10.1128/ec.00347-07] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A new myosin motor-like chitin synthase gene, chsVb, has been identified in the vascular wilt fungus Fusarium oxysporum f. sp. lycopersici. Phylogenetic analysis of the deduced amino acid sequence of the chsVb chitin synthase 2 domain (CS2) revealed that ChsVb belongs to class VII chitin synthases. The ChsVb myosin motor-like domain (MMD) is shorter than the MMD of class V chitin synthases and does not contain typical ATP-binding motifs. Targeted disrupted single (DeltachsVb) and double (DeltachsV DeltachsVb) mutants were unable to infect and colonize tomato plants or grow invasively on tomato fruit tissue. These strains were hypersensitive to compounds that interfere with fungal cell wall assembly, produced lemon-like shaped conidia, and showed swollen balloon-like structures in hyphal subapical regions, thickened walls, aberrant septa, and intrahyphal hyphae. Our results suggest that the chsVb gene is likely to function in polarized growth and confirm the critical importance of cell wall integrity in the complex infection process of this fungus.
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Cultural characteristics and extraction of the fungal pigment phleichrome from the phytopathogenic fungusCladosporium phlei. BIOTECHNOL BIOPROC E 2007. [DOI: 10.1007/bf02931348] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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