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Fernandes C, Casadevall A, Gonçalves T. Mechanisms of Alternaria pathogenesis in animals and plants. FEMS Microbiol Rev 2023; 47:fuad061. [PMID: 37884396 DOI: 10.1093/femsre/fuad061] [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: 05/08/2023] [Revised: 09/18/2023] [Accepted: 10/25/2023] [Indexed: 10/28/2023] Open
Abstract
Alternaria species are cosmopolitan fungi darkly pigmented by melanin that infect numerous plant species causing economically important agricultural spoilage of various food crops. Alternaria spp. also infect animals, being described as entomopathogenic fungi but also infecting warm-blooded animals, including humans. Their clinical importance in human health, as infection agents, lay in the growing number of immunocompromised patients. Moreover, Alternaria spp. are considered some of the most abundant and potent sources of airborne sensitizer allergens causing allergic respiratory diseases, as severe asthma. Among the numerous strategies deployed by Alternaria spp. to attack their hosts, the production of toxins, carrying critical concerns to public health as food contaminant, and the production of hydrolytic enzymes such as proteases, can be highlighted. Alternaria proteases also trigger allergic symptoms in individuals with fungal sensitization, acting as allergens and facilitating antigen access to the host subepithelium. Here, we review the current knowledge about the mechanisms of Alternaria pathogenesis in plants and animals, the strategies used by Alternaria to cope with the host defenses, and the involvement Alternaria allergens and mechanisms of sensitization.
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Affiliation(s)
- Chantal Fernandes
- CNC-UC - Center for Neuroscience and Cell Biology of Coimbra, Rua Larga, 3004-504 Coimbra, Portugal
| | - Arturo Casadevall
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Wolfe Street, Room E5132, Baltimore, Maryland 21205, USA
| | - Teresa Gonçalves
- CNC-UC - Center for Neuroscience and Cell Biology of Coimbra, Rua Larga, 3004-504 Coimbra, Portugal
- FMUC - Faculty of Medicine, University of Coimbra, Rua Larga, 3004-504 Coimbra, Portugal
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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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Trieu TA, Nguyen PA, Le MN, Chu HN. Myosin-II proteins are involved in the growth, morphogenesis, and virulence of the human pathogenic fungus Mucor circinelloides. Front Cell Infect Microbiol 2022; 12:1031463. [PMID: 36590583 PMCID: PMC9800795 DOI: 10.3389/fcimb.2022.1031463] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 11/25/2022] [Indexed: 12/23/2022] Open
Abstract
Mucormycosis is an emerging lethal invasive fungal infection. The infection caused by fungi belonging to the order Mucorales has been reported recently as one of the most common fungal infections among COVID-19 patients. The lack of understanding of pathogens, particularly at the molecular level, is one of the reasons for the difficulties in the management of the infection. Myosin is a diverse superfamily of actin-based motor proteins that have various cellular roles. Four families of myosin motors have been found in filamentous fungi, including myosin I, II, V, and fungus-specific chitin synthase with myosin motor domains. Our previous study on Mucor circinelloides, a common pathogen of mucormycosis, showed that the Myo5 protein (ID 51513) belonging to the myosin type V family had a critical impact on the growth and virulence of this fungus. In this study, to investigate the roles of myosin II proteins in M. circinelloides, silencing phenotypes and null mutants corresponding to myosin II encoding genes, designated mcmyo2A (ID 149958) and mcmyo2B (ID 136314), respectively, were generated. Those mutant strains featured a significantly reduced growth rate and impaired sporulation in comparison with the wild-type strain. Notably, the disruption of mcmyo2A led to an almost complete lack of sporulation. Both mutant strains displayed abnormally short, septate, and inflated hyphae with the presence of yeast-like cells and an unusual accumulation of pigment-filled vesicles. In vivo virulence assays of myosin-II mutant strains performed in the invertebrate model Galleria mellonella indicated that the mcmyo2A-knockout strain was avirulent, while the pathogenesis of the mcmyo2B null mutant was unaltered despite the low growth rate and impaired sporulation. The findings provide suggestions for critical contributions of the myosin II proteins to the polarity growth, septation, morphology, pigment transportation, and pathogenesis of M. circinelloides. The findings also implicate the myosin family as a potential target for future therapy to treat mucormycosis.
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Affiliation(s)
- Trung Anh Trieu
- Department of Genetics - Biochemistry, Faculty of Biology, Hanoi National University of Education, Hanoi, Vietnam,*Correspondence: Trung Anh Trieu,
| | - Phuong Anh Nguyen
- Department of Genetics - Biochemistry, Faculty of Biology, Hanoi National University of Education, Hanoi, Vietnam
| | - Mai Ngoc Le
- Department of Genetics - Biochemistry, Faculty of Biology, Hanoi National University of Education, Hanoi, Vietnam
| | - Huy Nhat Chu
- Environmental Bioremediation Laboratory, Institute of Biotechnology, Vietnam Academy of Science and Technology, Hanoi, Vietnam,Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Hanoi, Vietnam
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Comparative genomics reveals the origin of fungal hyphae and multicellularity. Nat Commun 2019; 10:4080. [PMID: 31501435 PMCID: PMC6733946 DOI: 10.1038/s41467-019-12085-w] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 08/20/2019] [Indexed: 02/01/2023] Open
Abstract
Hyphae represent a hallmark structure of multicellular fungi. The evolutionary origins of hyphae and of the underlying genes are, however, hardly known. By systematically analyzing 72 complete genomes, we here show that hyphae evolved early in fungal evolution probably via diverse genetic changes, including co-option and exaptation of ancient eukaryotic (e.g. phagocytosis-related) genes, the origin of new gene families, gene duplications and alterations of gene structure, among others. Contrary to most multicellular lineages, the origin of filamentous fungi did not correlate with expansions of kinases, receptors or adhesive proteins. Co-option was probably the dominant mechanism for recruiting genes for hypha morphogenesis, while gene duplication was apparently less prevalent, except in transcriptional regulators and cell wall - related genes. We identified 414 novel gene families that show correlated evolution with hyphae and that may have contributed to its evolution. Our results suggest that hyphae represent a unique multicellular organization that evolved by limited fungal-specific innovations and gene duplication but pervasive co-option and modification of ancient eukaryotic functions.
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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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Hinkel L, Ospina-Giraldo MD. Structural characterization of a putative chitin synthase gene in Phytophthora spp. and analysis of its transcriptional activity during pathogenesis on potato and soybean plants. Curr Genet 2017; 63:909-921. [PMID: 28314907 DOI: 10.1007/s00294-017-0687-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 02/06/2017] [Accepted: 02/20/2017] [Indexed: 12/13/2022]
Abstract
Although chitin is a major component of the fungal cell wall, in oomycetes (fungal-like organisms), this compound has only been found in very little amounts, mostly in the cell wall of members of the genera Achlya and Saprolegnia. In the oomycetes Phytophthora infestans and P. sojae the presence of chitin has not been demonstrated; however, the gene putatively encoding chitin synthase (CHS), the enzyme that synthesizes chitin, is present in their genomes. The evolutionary significance of the CHS gene in P. infestans and P. sojae genomes is not fully understood and, therefore, further studies are warranted. We have cloned and characterized the putative CHS genes from two Phytophthora spp. and multiple isolates of P. infestans and P. sojae and analyzed their phylogenetic relationships. We also conducted CHS inhibition assays and measured CHS transcriptional activity in Phytophthora spp. during infection of susceptible plants. Results of our investigations suggest that CHS contains all the motifs that are typical in CHS genes of fungal origin and is expressed, at least at the mRNA level, during in vitro and in planta growth. In infected tissues, the highest levels of expression occurred in the first 12 h post inoculation. In addition, results from our inhibition experiments appear to suggest that CHS activity is important for P. infestans normal vegetative growth. Because of the considerable variation in expression during infection when compared to basal expression observed in in vitro cultures of non-sporulating mycelium, we hypothesize that CHS may have a meaningful role in Phytophthora pathogenicity.
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Affiliation(s)
- Lauren Hinkel
- Biology Department, Lafayette College, Easton, PA, USA
- Department of Cellular, Molecular, and Biomedical Sciences, University of Vermont, Burlington, VT, USA
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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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Aspergillus fumigatus Trehalose-Regulatory Subunit Homolog Moonlights To Mediate Cell Wall Homeostasis through Modulation of Chitin Synthase Activity. mBio 2017; 8:mBio.00056-17. [PMID: 28442603 PMCID: PMC5405227 DOI: 10.1128/mbio.00056-17] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Trehalose biosynthesis is found in fungi but not humans. Proteins involved in trehalose biosynthesis are essential for fungal pathogen virulence in humans and plants through multiple mechanisms. Loss of canonical trehalose biosynthesis genes in the human pathogen Aspergillus fumigatus significantly alters cell wall structure and integrity, though the mechanistic link between these virulence-associated pathways remains enigmatic. Here we characterize genes, called tslA and tslB, which encode proteins that contain domains similar to those corresponding to trehalose-6-phosphate phosphatase but lack critical catalytic residues for phosphatase activity. Loss of tslA reduces trehalose content in both conidia and mycelia, impairs cell wall integrity, and significantly alters cell wall structure. To gain mechanistic insights into the role that TslA plays in cell wall homeostasis, immunoprecipitation assays coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) were used to reveal a direct interaction between TslA and CsmA, a type V chitin synthase enzyme. TslA regulates not only chitin synthase activity but also CsmA sub-cellular localization. Loss of TslA impacts the immunopathogenesis of murine invasive pulmonary aspergillosis through altering cytokine production and immune cell recruitment. In conclusion, our data provide a novel model whereby proteins in the trehalose pathway play a direct role in fungal cell wall homeostasis and consequently impact fungus-host interactions. Human fungal infections are increasing globally due to HIV infections and increased use of immunosuppressive therapies for many diseases. Therefore, new antifungal drugs with reduced side effects and increased efficacy are needed to improve treatment outcomes. Trehalose biosynthesis exists in pathogenic fungi and is absent in humans. Components of the trehalose biosynthesis pathway are important for the virulence of human-pathogenic fungi, including Aspergillus fumigatus. Consequently, it has been proposed that components of this pathway are potential targets for antifungal drug development. However, how trehalose biosynthesis influences the fungus-host interaction remains enigmatic. One phenotype associated with fungal trehalose biosynthesis mutants that remains enigmatic is cell wall perturbation. Here we discovered a novel moonlighting role for a regulatory-like subunit of the trehalose biosynthesis pathway in A. fumigatus that regulates cell wall homeostasis through modulation of chitin synthase localization and activity. As the cell wall is a current and promising therapeutic target for fungal infections, understanding the role of trehalose biosynthesis in cell wall homeostasis and virulence is expected to help define new therapeutic opportunities.
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Jeong HY, Chae KS, Whang SS. Presence of a mannoprotein, MnpAp, in the hyphal cell wall ofAspergillus nidulans. Mycologia 2017. [DOI: 10.1080/15572536.2005.11832996] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
| | - Keon-Sang Chae
- Division of Biological Sciences, Chonbuk National University, Chonju, Chonbuk 561-756, Republic of Korea
| | - Sung Soo Whang
- Division of Science Education, Chonbuk National University, Chonju, Chonbuk 561-756, Republic of Korea
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Herold I, Yarden O. Regulation of Neurospora crassa cell wall remodeling via the cot-1 pathway is mediated by gul-1. Curr Genet 2016; 63:145-159. [PMID: 27363849 DOI: 10.1007/s00294-016-0625-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 06/14/2016] [Accepted: 06/16/2016] [Indexed: 11/29/2022]
Abstract
Impairment of the Neurospora crassa Nuclear DBF2-related kinase-encoding gene cot-1 results in pleiotropic effects, including abnormally thick hyphal cell walls and septa. An increase in the transcript abundance of genes encoding chitin and glucan synthases and the chitinase gh18-5, but not the cell wall integrity pathway transcription factor rlm-1, accompany the phenotypic changes observed. Deletion of chs-5 or chs-7 in a cot-1 background results in a reduction of hyperbranching frequency characteristic of the cot-1 parent. gul-1 (a homologue of the yeast SSD1 gene) encodes a translational regulator and has been shown to partially suppress cot-1. We demonstrate that the high expression levels of the cell wall remodeling genes analyzed is curbed, and reaches near wild type levels, when gul-1 is inactivated. This is accompanied by morphological changes that include reduced cell wall thickness and restoration of normal chitin levels. We conclude that gul-1 is a mediator of cell wall remodeling within the cot-1 pathway.
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Affiliation(s)
- Inbal Herold
- Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, 7610000, Rehovot, Israel
| | - Oded Yarden
- Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, 7610000, Rehovot, Israel.
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Fernandes C, Gow NA, Gonçalves T. The importance of subclasses of chitin synthase enzymes with myosin-like domains for the fitness of fungi. FUNGAL BIOL REV 2016. [DOI: 10.1016/j.fbr.2016.03.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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12
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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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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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Mélida H, Sain D, Stajich JE, Bulone V. Deciphering the uniqueness of Mucoromycotina cell walls by combining biochemical and phylogenomic approaches. Environ Microbiol 2014; 17:1649-62. [DOI: 10.1111/1462-2920.12601] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Revised: 08/06/2014] [Accepted: 08/11/2014] [Indexed: 11/30/2022]
Affiliation(s)
- Hugo Mélida
- Division of Glycoscience; School of Biotechnology; Royal Institute of Technology (KTH); AlbaNova University Centre; Stockholm Sweden
| | - Divya Sain
- Department of Plant Pathology and Microbiology; University of California; Riverside CA 92507 USA
| | - Jason E. Stajich
- Department of Plant Pathology and Microbiology; University of California; Riverside CA 92507 USA
| | - Vincent Bulone
- Division of Glycoscience; School of Biotechnology; Royal Institute of Technology (KTH); AlbaNova University Centre; Stockholm Sweden
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Myosin Motor-Like Domain of the Class VI Chitin Synthase CsmB Is Essential to Its Functions inAspergillus nidulans. Biosci Biotechnol Biochem 2014; 73:1163-7. [DOI: 10.1271/bbb.90074] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [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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Myosin Motor-Like Domain of Class VI Chitin Synthase CsmB of Aspergillus nidulans Is Not Functionally Equivalent to That of Class V Chitin Synthase CsmA. Biosci Biotechnol Biochem 2013; 77:369-74. [DOI: 10.1271/bbb.120822] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Abstract
Abstract
The size, morphology and species-specific texture of mollusc shell biominerals is one of the unresolved questions in nature. In search of molecular control principles, chitin has been identified by Weiner and Traub (FEBS Lett. 1980, 111:311–316) as one of the organic compounds with a defined co-organization with mineral phases. Chitin fibers can be aligned with certain mineralogical axes of crystalline calcium carbonate in a species-specific manner. These original observations motivated the functional characterization of chitin forming enzymes in molluscs. The full-length cDNA cloning of mollusc chitin synthases identified unique myosin domains as part of the biological control system. The potential impact of molecular motors and other conserved domains of these complex transmembrane enzymes on the evolution of shell biomineralization is investigated and discussed in this article.
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Schuster M, Treitschke S, Kilaru S, Molloy J, Harmer NJ, Steinberg G. Myosin-5, kinesin-1 and myosin-17 cooperate in secretion of fungal chitin synthase. EMBO J 2012; 31:214-27. [PMID: 22027862 PMCID: PMC3252574 DOI: 10.1038/emboj.2011.361] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2011] [Accepted: 09/06/2011] [Indexed: 11/08/2022] Open
Abstract
Plant infection by pathogenic fungi requires polarized secretion of enzymes, but little is known about the delivery pathways. Here, we investigate the secretion of cell wall-forming chitin synthases (CHSs) in the corn pathogen Ustilago maydis. We show that peripheral filamentous actin (F-actin) and central microtubules (MTs) form independent tracks for CHSs delivery and both cooperate in cell morphogenesis. The enzyme Mcs1, a CHS that contains a myosin-17 motor domain, is travelling along both MTs and F-actin. This transport is independent of kinesin-3, but mediated by kinesin-1 and myosin-5. Arriving vesicles pause beneath the plasma membrane, but only ~15% of them get exocytosed and the majority is returned to the cell centre by the motor dynein. Successful exocytosis at the cell tip and, to a lesser extent at the lateral parts of the cell requires the motor domain of Mcs1, which captures and tethers the vesicles prior to secretion. Consistently, Mcs1-bound vesicles transiently bind F-actin but show no motility in vitro. Thus, kinesin-1, myosin-5 and dynein mediate bi-directional motility, whereas myosin-17 introduces a symmetry break that allows polarized secretion.
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Affiliation(s)
| | - Steffi Treitschke
- Department of Biosciences, University of Exeter, Exeter, UK
- Personalisierte Tumortherapie, Fraunhofer ITEM-R, Regensburg, Germany
| | | | - Justin Molloy
- MRC National Institute for Medical Research, Mill Hill London, UK
| | | | - Gero Steinberg
- Department of Biosciences, University of Exeter, Exeter, UK
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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: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] 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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Zhang J, Tan K, Wu X, Chen G, Sun J, Reck-Peterson SL, Hammer JA, Xiang X. Aspergillus myosin-V supports polarized growth in the absence of microtubule-based transport. PLoS One 2011; 6:e28575. [PMID: 22194856 PMCID: PMC3237463 DOI: 10.1371/journal.pone.0028575] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Accepted: 11/10/2011] [Indexed: 12/23/2022] Open
Abstract
In the filamentous fungus Aspergillus nidulans, both microtubules and actin filaments are important for polarized growth at the hyphal tip. Less clear is how different microtubule-based and actin-based motors work together to support this growth. Here we examined the role of myosin-V (MYOV) in hyphal growth. MYOV-depleted cells form elongated hyphae, but the rate of hyphal elongation is significantly reduced. In addition, although wild type cells without microtubules still undergo polarized growth, microtubule disassembly abolishes polarized growth in MYOV-depleted cells. Thus, MYOV is essential for polarized growth in the absence of microtubules. Moreover, while a triple kinesin null mutant lacking kinesin-1 (KINA) and two kinesin-3s (UNCA and UNCB) undergoes hyphal elongation and forms a colony, depleting MYOV in this triple mutant results in lethality due to a severe defect in polarized growth. These results argue that MYOV, through its ability to transport secretory cargo, can support a significant amount of polarized hyphal tip growth in the absence of any microtubule-based transport. Finally, our genetic analyses also indicate that KINA (kinesin-1) rather than UNCA (kinesin-3) is the major kinesin motor that supports polarized growth in the absence of MYOV.
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Affiliation(s)
- Jun Zhang
- Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences, F. Edward Hébert School of Medicine, Bethesda, Maryland, United States of America
| | - Kaeling Tan
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Xufeng Wu
- Laboratory of Cell Biology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Guifang Chen
- Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences, F. Edward Hébert School of Medicine, Bethesda, Maryland, United States of America
| | - Jinjin Sun
- Laboratory of Cell Biology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland, United States of America
- River Hill High School, Clarksville, Maryland, United States of America
| | - Samara L. Reck-Peterson
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - John A. Hammer
- Laboratory of Cell Biology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail: (JH); (XX)
| | - Xin Xiang
- Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences, F. Edward Hébert School of Medicine, Bethesda, Maryland, United States of America
- * E-mail: (JH); (XX)
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24
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Steinberg G. Motors in fungal morphogenesis: cooperation versus competition. Curr Opin Microbiol 2011; 14:660-7. [DOI: 10.1016/j.mib.2011.09.013] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2011] [Accepted: 09/27/2011] [Indexed: 10/15/2022]
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Treitschke S, Doehlemann G, Schuster M, Steinberg G. The myosin motor domain of fungal chitin synthase V is dispensable for vesicle motility but required for virulence of the maize pathogen Ustilago maydis. THE PLANT CELL 2010; 22:2476-94. [PMID: 20663961 PMCID: PMC2929105 DOI: 10.1105/tpc.110.075028] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2010] [Revised: 06/26/2010] [Accepted: 07/08/2010] [Indexed: 05/23/2023]
Abstract
Class V chitin synthases are fungal virulence factors required for plant infection. They consist of a myosin motor domain fused to a membrane-spanning chitin synthase region that participates in fungal cell wall formation. The function of the motor domain is unknown, but it might deliver the myosin chitin synthase-attached vesicles to the growth region. Here, we analyze the importance of both domains in Mcs1, the chitin synthase V of the maize smut fungus Ustilago maydis. By quantitative analysis of disease symptoms, tissue colonization, and single-cell morphogenic parameters, we demonstrate that both domains are required for fungal virulence. Fungi carrying mutations in the chitin synthase domain are rapidly recognized and killed by the plant, whereas fungi carrying a deletion of the motor domain show alterations in cell wall composition but can invade host tissue and cause a moderate plant response. We also show that Mcs1-bound vesicles exhibit long-range movement for up to 20 microm at a velocity of approximately 1.75 microm/s. Apical Mcs1 localization depends on F-actin and the motor domain, whereas Mcs1 motility requires microtubules and persists when the Mcs1 motor domain is deleted. Our results suggest that the myosin motor domain of ChsV supports exocytosis but not long-range delivery of transport vesicles.
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Affiliation(s)
- Steffi Treitschke
- School of Biosciences, University of Exeter, Exeter EX4 4QD, United Kingdom
- Max Planck Institute for Terrestrial Microbiology, D-35043 Marburg, Germany
| | - Gunther Doehlemann
- Max Planck Institute for Terrestrial Microbiology, D-35043 Marburg, Germany
| | - Martin Schuster
- School of Biosciences, University of Exeter, Exeter EX4 4QD, United Kingdom
| | - Gero Steinberg
- School of Biosciences, University of Exeter, Exeter EX4 4QD, United Kingdom
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Lenardon MD, Munro CA, Gow NAR. Chitin synthesis and fungal pathogenesis. Curr Opin Microbiol 2010; 13:416-23. [PMID: 20561815 PMCID: PMC2923753 DOI: 10.1016/j.mib.2010.05.002] [Citation(s) in RCA: 286] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2010] [Revised: 05/04/2010] [Accepted: 05/06/2010] [Indexed: 11/25/2022]
Abstract
Chitin is an essential part of the carbohydrate skeleton of the fungal cell wall and is a molecule that is not represented in humans and other vertebrates. Complex regulatory mechanisms enable chitin to be positioned at specific sites throughout the cell cycle to maintain the overall strength of the wall and enable rapid, life-saving modifications to be made under cell wall stress conditions. Chitin has also recently emerged as a significant player in the activation and attenuation of immune responses to fungi and other chitin-containing parasites. This review summarises latest advances in the analysis of chitin synthesis regulation in the context of fungal pathogenesis.
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Affiliation(s)
- Megan D Lenardon
- Aberdeen Fungal Group, School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Aberdeen, AB25 2ZD, UK
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Transcription levels of CHS5 and CHS4 genes in Paracoccidioides brasiliensis mycelial phase, respond to alterations in external osmolarity, oxidative stress and glucose concentration. ACTA ACUST UNITED AC 2009; 113:1091-6. [PMID: 19616626 DOI: 10.1016/j.mycres.2009.07.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2009] [Revised: 07/07/2009] [Accepted: 07/09/2009] [Indexed: 01/12/2023]
Abstract
The complete sequence of Paracoccidioides brasiliensis CHS5 gene, encoding a putative chitin synthase revealed a 5583nt open reading frame, interrupted by three introns of 82, 87 and 97bp (GenBank Accession No EF654132). The deduced protein contains 1861 amino acids with a predicted molecular weight of 206.9kDa. Both its large size and the presence of a N-terminal region of approx. 800 residues with a characteristic putative myosin motor-like domain, allow us to include PbrChs5 into class V fungal chitin synthases. Sequence analysis of over 4kb from the 5' UTR region in CHS5, revealed the presence of a previously reported CHS4 gene in P. brasiliensis, arranged in a head-to-head configuration with CHS5. A motif search in this shared region showed the presence of stress response elements (STREs), three binding sites for the transcription activators Rlm1p (known to be stimulated by hypo-osmotic stress) and clusters of Adr1 (related to glucose repression). A quantitative RT-PCR analysis pointed to changes in transcription levels for both genes following oxidative stress, alteration of external osmolarity and under glucose-repressible conditions, suggesting a common regulatory mechanism of transcription.
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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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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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Odronitz F, Kollmar M. Drawing the tree of eukaryotic life based on the analysis of 2,269 manually annotated myosins from 328 species. Genome Biol 2008; 8:R196. [PMID: 17877792 PMCID: PMC2375034 DOI: 10.1186/gb-2007-8-9-r196] [Citation(s) in RCA: 283] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2007] [Revised: 09/17/2007] [Accepted: 09/18/2007] [Indexed: 01/03/2023] Open
Abstract
The tree of eukaryotic life was reconstructed based on the analysis of 2,269 myosin motor domains from 328 organisms, confirming some accepted relationships of major taxa and resolving disputed and preliminary classifications. Background The evolutionary history of organisms is expressed in phylogenetic trees. The most widely used phylogenetic trees describing the evolution of all organisms have been constructed based on single-gene phylogenies that, however, often produce conflicting results. Incongruence between phylogenetic trees can result from the violation of the orthology assumption and stochastic and systematic errors. Results Here, we have reconstructed the tree of eukaryotic life based on the analysis of 2,269 myosin motor domains from 328 organisms. All sequences were manually annotated and verified, and were grouped into 35 myosin classes, of which 16 have not been proposed previously. The resultant phylogenetic tree confirms some accepted relationships of major taxa and resolves disputed and preliminary classifications. We place the Viridiplantae after the separation of Euglenozoa, Alveolata, and Stramenopiles, we suggest a monophyletic origin of Entamoebidae, Acanthamoebidae, and Dictyosteliida, and provide evidence for the asynchronous evolution of the Mammalia and Fungi. Conclusion Our analysis of the myosins allowed combining phylogenetic information derived from class-specific trees with the information of myosin class evolution and distribution. This approach is expected to result in superior accuracy compared to single-gene or phylogenomic analyses because the orthology problem is resolved and a strong determinant not depending on any technical uncertainties is incorporated, the class distribution. Combining our analysis of the myosins with high quality analyses of other protein families, for example, that of the kinesins, could help in resolving still questionable dependencies at the origin of eukaryotic life.
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Affiliation(s)
- Florian Odronitz
- Department of NMR-based Structural Biology, Max-Planck-Institute for Biophysical Chemistry, Am Fassberg, 37077 Goettingen, Germany
| | - Martin Kollmar
- Department of NMR-based Structural Biology, Max-Planck-Institute for Biophysical Chemistry, Am Fassberg, 37077 Goettingen, Germany
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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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Liu H, Szaniszlo PJ. Transcription and expression analyses of WdCHS5, which encodes a class V chitin synthase with a myosin motor-like domain in Wangiella (Exophiala) dermatitidis. FEMS Microbiol Lett 2007; 276:99-105. [PMID: 17937668 DOI: 10.1111/j.1574-6968.2007.00920.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
WdChs5p in Wangiella dermatitidis is a class V chitin synthase that is required for sustained cell growth at the temperature of infection (37 degrees C) and its encoding gene, WdCHS5, has a differential expression feature. Nuclear run-on and mRNA stability assays showed that increased WdCHS5 mRNA synthesis was the major factor responsible for the increased WdCHS5 transcript at 37 degrees C. Epitope tagging of WdChs5p in W. dermatitidis showed that the WdChs5p-myc protein had a differential expression feature that was similar to the differential transcription of the WdCHS5 gene. In conclusion, it is shown that transcriptional regulation is the first and probably the most important control point of the expression of WdCHS5.
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Affiliation(s)
- Hongbo Liu
- Section of Molecular Genetics and Microbiology, School of Biological Science and Institute of Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX 78712-1095, USA
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Riquelme M, Bartnicki-García S, González-Prieto JM, Sánchez-León E, Verdín-Ramos JA, Beltrán-Aguilar A, Freitag M. Spitzenkorper localization and intracellular traffic of green fluorescent protein-labeled CHS-3 and CHS-6 chitin synthases in living hyphae of Neurospora crassa. EUKARYOTIC CELL 2007; 6:1853-64. [PMID: 17644657 PMCID: PMC2043383 DOI: 10.1128/ec.00088-07] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The subcellular location and traffic of two selected chitin synthases (CHS) from Neurospora crassa, CHS-3 and CHS-6, labeled with green fluorescent protein (GFP), were studied by high-resolution confocal laser scanning microscopy. While we found some differences in the overall distribution patterns and appearances of CHS-3-GFP and CHS-6-GFP, most features were similar and were observed consistently. At the hyphal apex, fluorescence congregated into a conspicuous single body corresponding to the location of the Spitzenkörper (Spk). In distal regions (beyond 40 microm from the apex), CHS-GFP revealed a network of large endomembranous compartments that was predominantly comprised of irregular tubular shapes, while some compartments were distinctly spherical. In the distal subapex (20 to 40 microm from the apex), fluorescence was observed in globular bodies that appeared to disintegrate into vesicles as they advanced forward until reaching the proximal subapex (5 to 20 microm from the apex). CHS-GFP was also conspicuously found delineating developing septa. Analysis of fluorescence recovery after photobleaching suggested that the fluorescence of the Spk originated from the advancing population of microvesicles (chitosomes) in the subapex. The inability of brefeldin A to interfere with the traffic of CHS-containing microvesicles and the lack of colocalization of CHS-GFP with the endoplasmic reticulum (ER)-Golgi body fluorescent dyes lend support to the idea that CHS proteins are delivered to the cell surface via an alternative route distinct from the classical ER-Golgi body secretory pathway.
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Affiliation(s)
- Meritxell Riquelme
- Department of Microbiology, Center for Scientific Research and Higher Education of Ensenada (CICESE), San Ysidro, CA 92143-0222, USA.
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Suzuki M, Sakuda S, Nagasawa H. Identification of chitin in the prismatic layer of the shell and a chitin synthase gene from the Japanese pearl oyster, Pinctada fucata. Biosci Biotechnol Biochem 2007; 71:1735-44. [PMID: 17617722 DOI: 10.1271/bbb.70140] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The shell of the Japanese pearl oyster, Pinctada fucata, consists of two layers, the prismatic layer on the outside and the nacreous layer on the inside, both of which comprise calcium carbonate and organic matrices. Previous studies indicate that the nacreous organic matrix of the central layer of the framework surrounding the aragonite tablet is beta-chitin, but it remains unknown whether organic matrices in the prismatic layer contain chitin or not. In the present study, we identified chitin in the prismatic layer of the Japanese pearl oyster, Pinctada fucata, with a combination of Calcofluor White staining with IR and NMR spectral analyses. Furthermore, we cloned a cDNA encoding chitin synthase (PfCHS1) that produces chitin, contributing to the formation of the framework for calcification in the shell.
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Affiliation(s)
- Michio Suzuki
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo, Japan
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36
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Isolation and characterization of the gene encoding a chitin synthase with a myosin motor-like domain from the edible basidiomycetous mushroom, Lentinula edodes, and its expression in the course of fruit-body formation. MYCOSCIENCE 2007. [DOI: 10.1007/s10267-006-0339-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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37
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Mandel MA, Galgiani JN, Kroken S, Orbach MJ. Coccidioides posadasii contains single chitin synthase genes corresponding to classes I to VII. Fungal Genet Biol 2006; 43:775-88. [PMID: 16857399 DOI: 10.1016/j.fgb.2006.05.005] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2005] [Revised: 05/17/2006] [Accepted: 05/23/2006] [Indexed: 11/20/2022]
Abstract
Coccidioides posadasii is a dimorphic fungal pathogen of humans and other mammals. The switch between saprobic and parasitic growth involves synthesis of new cell walls of which chitin is a significant component. To determine whether particular subsets of chitin synthases (CHSes) are responsible for production of chitin at different stages of differentiation, we have isolated six CHS genes from this fungus. They correspond, together with another reported CHS gene, to single members of the seven defined classes of chitin synthases (classes I-VII). Using Real-Time RT-PCR we show their pattern of expression during morphogenesis. CpCHS2, CpCHS3, and CpCHS6 are preferentially expressed during the saprobic phase, while CpCHS1 and CpCHS4 are more highly expressed during the parasitic phase. CpCHS5 and CpCHS7 expression is similar in both saprobic and parasitic phases. Because C. posadasii contains single members of the seven classes of CHSes found in fungi, it is a good model to investigate the putatively different roles of these genes in fungal growth and differentiation.
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Affiliation(s)
- M Alejandra Mandel
- Department of Plant Sciences, Division of Plant Pathology and Microbiology, University of Arizona, Tucson, AZ 85721-0036, USA
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38
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Broeker K, Fehser S, Moerschbacher BM. Survey and expression analysis of five new chitin synthase genes in the biotrophic rust fungus Puccinia graminis. Curr Genet 2006; 50:295-305. [PMID: 16924501 DOI: 10.1007/s00294-006-0094-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2006] [Revised: 07/11/2006] [Accepted: 07/18/2006] [Indexed: 01/29/2023]
Abstract
We have isolated and characterised the first set of chitin synthase genes from a rust fungus, a large group of economically highly important, obligately biotrophic plant pathogens. Puccinia graminis was used as a model organism for the rust fungi which are not well investigated on the molecular level today. One of the major structural components of most fungal cell walls is the chitin polymer which is synthesised by a family of enzymes called chitin synthases. In P. graminis, we have isolated five new chitin synthase genes from four different classes, chsII, chsIIIa, chsIIIb, chsIV, and chsV. The genes contain a high number of introns, unusual for other known fungal chitin synthases. The dinucleic stage of the fungus seems to contain two slightly different genes or alleles for four isoforms. One isoform, chsIIIa, seems to be expressed only in the youngest stages of fungal growth. Analysis of the derived proteins shows that together with other basidiomycete CHS, the pgtCHS form separate subgroups in the phylogenetic tree. This set of five rust chitin synthase genes, with some unusual features compared to known fungal chitin synthases, allows new insights into chitin synthase classification, and may help in the development of novel functional fungicides.
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Affiliation(s)
- Katja Broeker
- Institut für Biochemie und Biotechnologie der Pflanzen, Westfälische Wilhelms-Universität Münster, Münster, Germany
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39
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Takeshita N, Yamashita S, Ohta A, Horiuchi H. Aspergillus nidulans class V and VI chitin synthases CsmA and CsmB, each with a myosin motor-like domain, perform compensatory functions that are essential for hyphal tip growth. Mol Microbiol 2006; 59:1380-94. [PMID: 16468983 DOI: 10.1111/j.1365-2958.2006.05030.x] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The polarized synthesis of cell wall components such as chitin is essential for the hyphal tip growth of filamentous fungi. The actin cytoskeleton is known to play important roles in the determination of hyphal polarity in Aspergillus nidulans. Previously, we suggested that CsmA, a chitin synthase with a myosin motor-like domain (MMD), was involved in polarized chitin synthesis in a manner dependent on the interaction between the MMD and the actin cytoskeleton. The genome database indicates that A. nidulans possesses another gene encoding another chitin synthase with an MMD. In this study, we characterized this gene, which we designated csmB. The csmB null mutants examined were viable, although they exhibited defective phenotypes, including the formation of balloons and intrahyphal hyphae and the lysis of subapical regions, which were similar to those obtained with csmA null mutants. Moreover, csmA csmB double null mutants were not viable. Mutants in which csmB was deleted and the expression of csmA was under the control of the alcA promoter were viable but severely impaired in terms of hyphal growth under alcA-repressing conditions. We revealed that CsmB with three copies of a FLAG epitope tag localized at the hyphal tips and forming septa, and that the MMD of CsmB was able to bind to actin filaments in vitro. These results suggest that CsmA and CsmB perform compensatory functions that are essential for hyphal tip growth.
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Affiliation(s)
- Norio Takeshita
- Department of Biotechnology, The University of Tokyo, 1-1-1 Yayoi, Tokyo 113-8657, Japan
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40
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Amnuaykanjanasin A, Epstein L. A class Vb chitin synthase in Colletotrichum graminicola is localized in the growing tips of multiple cell types, in nascent septa, and during septum conversion to an end wall after hyphal breakage. PROTOPLASMA 2006; 227:155-64. [PMID: 16520880 DOI: 10.1007/s00709-005-0126-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2005] [Accepted: 05/03/2005] [Indexed: 05/07/2023]
Abstract
Previous complementation of a chitin synthase class Vb null mutant (Colletotrichum graminicola chsA) indicated that the encoded protein is responsible for approximately 30% of the conidial chitin, is essential for conidial wall strength in media with high water potential, and contributes to strength of hyphal tips. We complemented a chsA null mutant with chsA fused to the green-fluorescent protein (sgfp) gene driven by a heterologous constitutively expressed promoter. Comparisons of the strain with the ectopic chsA-sgfp to the wild type indicated that ChsA-sGFP serves the same biological functions as ChsA in that like the wild type, the chsADelta chsA::sgfp (EC) had conidia that did not explode and hyphal tips that did not swell. Confocal microscopy of ChsA-sGFP (EC) cells stained with the membrane stain FM 4-64 (N-(3-triethylammoniumpropyl)-4-(6-(4-(diethylamino)phenyl)hexatrienyl)pyridinium dibromide) indicated that ChsA is localized in the plasma membrane of the following: growing apices of hyphal branches, conidiophores, and falcate and oval conidia; in nascent septa; and in septa that are being converted to an end wall after hyphal breakage. The data support the hypothesis that chsA either directly or indirectly encodes the information for its localization, that ChsA is localized in the plasma membrane, and that the class Vb enzyme produces chitin synthase in multiple cells and after wall breakage.
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Affiliation(s)
- A Amnuaykanjanasin
- Combinatorial Biosynthesis Laboratory, National Center for Genetic Engineering and Biotechnology, Pathumthani
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41
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Weiss IM, Schönitzer V, Eichner N, Sumper M. The chitin synthase involved in marine bivalve mollusk shell formation contains a myosin domain. FEBS Lett 2006; 580:1846-52. [PMID: 16513115 DOI: 10.1016/j.febslet.2006.02.044] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2006] [Revised: 02/16/2006] [Accepted: 02/16/2006] [Indexed: 11/22/2022]
Abstract
Chitin is a key component in mollusk nacre formation. However, the enzyme complex responsible for chitin deposition in the mollusk shell remained unknown. We cloned and characterized the chitin synthase of the marine bivalve mollusk Atrina rigida. We present here the first chitin synthase sequence from invertebrates containing an unconventional myosin motor head domain. We further show that a homologous gene for chitin synthase is expressed in the shell forming tissue of larval Mytilus galloprovincialis even in early embryonic stages. The new data presented here are the first clear-cut indication for a functional role of cytoskeletal forces in the precisely controlled mineral deposition process of mollusk shell biogenesis.
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Affiliation(s)
- Ingrid M Weiss
- Universität Regensburg, c/o Lehrstuhl Biochemie 1, Universitätsstr. 31, D-93055 Regensburg, Germany.
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42
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Weber I, Aßmann D, Thines E, Steinberg G. Polar localizing class V myosin chitin synthases are essential during early plant infection in the plant pathogenic fungus Ustilago maydis. THE PLANT CELL 2006; 18:225-42. [PMID: 16314447 PMCID: PMC1323495 DOI: 10.1105/tpc.105.037341] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Fungal chitin synthases (CHSs) form fibers of the cell wall and are crucial for substrate invasion and pathogenicity. Filamentous fungi contain up to 10 CHSs, which might reflect redundant functions or the complex biology of these fungi. Here, we investigate the complete repertoire of eight CHSs in the dimorphic plant pathogen Ustilago maydis. We demonstrate that all CHSs are expressed in yeast cells and hyphae. Green fluorescent protein (GFP) fusions to all CHSs localize to septa, whereas Chs5-GFP, Chs6-GFP, Chs7-yellow fluorescent protein (YFP), and Myosin chitin synthase1 (Mcs1)-YFP were found at growth regions of yeast-like cells and hyphae, indicating that they participate in tip growth. However, only the class IV CHS genes chs7 and chs5 are crucial for shaping yeast cells and hyphae ex planta. Although most CHS mutants were attenuated in plant pathogenicity, Deltachs6, Deltachs7, and Deltamcs1 mutants were drastically reduced in virulence. Deltamcs1 showed no morphological defects in hyphae, but Mcs1 became essential during invasion of the plant epidermis. Deltamcs1 hyphae entered the plant but immediately lost growth polarity and formed large aggregates of spherical cells. Our data show that the polar class IV CHSs are essential for morphogenesis ex planta, whereas the class V myosin-CHS is essential during plant infection.
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Affiliation(s)
| | | | | | - Gero Steinberg
- To whom correspondence should be addressed. E-mail ; fax 49-6421-178-599
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43
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Grimm LH, Kelly S, Krull R, Hempel DC. Morphology and productivity of filamentous fungi. Appl Microbiol Biotechnol 2005; 69:375-84. [PMID: 16317480 DOI: 10.1007/s00253-005-0213-5] [Citation(s) in RCA: 132] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2005] [Revised: 10/06/2005] [Accepted: 10/10/2005] [Indexed: 10/25/2022]
Abstract
Cultivation processes involving filamentous fungi have been optimised for decades to obtain high product yields. Several bulk chemicals like citric acid and penicillin are produced this way. A simple adaptation of cultivation parameters for new production processes is not possible though. Models explaining the correlation between process-dependent growth behaviour and productivity are therefore necessary to prevent long-lasting empiric test series. Yet, filamentous growth consists of a complex microscopic differentiation process from conidia to hyphae resulting in various macroscopically visible appearances. Early approaches to model this morphologic development are recapitulated in this review to explain current trends in this area of research. Tailoring morphology by adjusting process parameters is one side of the coin, but an ideal morphology has not even been found. This article reviews several reasons for this fact starting with nutrient supply in a fungal culture and presents recent advances in the investigation of fungal metabolism. It illustrates the challenge to unfold the relationship between morphology and productivity.
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Affiliation(s)
- L H Grimm
- Institute of Biochemical Engineering, Technical University of Braunschweig, Gaussstrasse 17, 38106 Braunschweig, Germany
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44
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Futai E, Sorimachi H, Jeong SY, Kitamoto K, Ishiura S, Suzuki K. Aspergillus oryzae palBory encodes a calpain-like protease: homology to Emericella nidulans PalB and conservation of functional regions. J Biosci Bioeng 2005; 88:438-40. [PMID: 16232641 DOI: 10.1016/s1389-1723(99)80223-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/1999] [Accepted: 07/09/1999] [Indexed: 11/17/2022]
Abstract
We have cloned and sequenced genomic DNA of Aspergillus oryzae palBory, orthologue of Emericella nidulans palB, which encodes a calpain-like protease modulating a signal transduction pathway during alkaline adaptation. The deduced amino acid sequence of PalBory is 70.0% identical to PalB over its entire length. The regions with high similarity revealed possible domains important for their function. This is the first step towards understanding the alkaline adaptation mechanism of A. oryzae, which would be very useful in the fermentation industry.
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Affiliation(s)
- E Futai
- Department of Molecular Biology, Institute of Molecular and Cellular Biosciences, University of Tokyo, Tokyo 113-0032, Japan
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45
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Ichinomiya M, Ohta A, Horiuchi H. Expression of asexual developmental regulator gene abaA is affected in the double mutants of classes I and II chitin synthase genes, chsC and chsA, of Aspergillus nidulans. Curr Genet 2005; 48:171-83. [PMID: 16082523 DOI: 10.1007/s00294-005-0004-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2005] [Revised: 05/31/2005] [Accepted: 06/06/2005] [Indexed: 11/26/2022]
Abstract
The chsA and chsC encode classes II and I chitin synthases, respectively, of the filamentous fungus Aspergillus nidulans. The DeltachsA DeltachsC double mutants (DeltaAC mutants) show defects in asexual development: a striking reduction in the number of conidiophores and aberrant conidiophore morphology. Here, we examined the involvement of regulatory genes for asexual development (brlA, abaA, and medA) in the conidiation defects of the DeltaAC mutants. Spatial expression patterns of brlA, abaA, and medA in conidiophores of the wild-type strains and DeltaAC mutants were examined by in-situ staining using a reporter gene; expression of either gene was detected at abnormal sterigmata in the DeltaAC mutants as well as at normal ones in the wild-type strain. However, abaA expression was not prominent at a subset of conidiophores developing long chains of aberrant sterigmata, suggesting that induction of the abaA expression was retarded in the DeltaAC mutants. Based on these results and those previously presented, possible mechanisms involved in the conidiation defects are discussed.
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Affiliation(s)
- Masayuki Ichinomiya
- Department of Biotechnology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, 113-8657 Tokyo, Japan
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46
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Ichinomiya M, Yamada E, Yamashita S, Ohta A, Horiuchi H. Class I and class II chitin synthases are involved in septum formation in the filamentous fungus Aspergillus nidulans. EUKARYOTIC CELL 2005; 4:1125-36. [PMID: 15947204 PMCID: PMC1151997 DOI: 10.1128/ec.4.6.1125-1136.2005] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The class II and class I chitin synthases of the filamentous fungus Aspergillus nidulans are encoded by chsA and chsC, respectively. Previously, we presented several lines of evidence suggesting that ChsA and ChsC have overlapping functions in maintaining cell wall integrity. In order to determine the functions of these chitin synthases, we employed electron and fluorescence microscopy and investigated in detail the cell wall of a DeltachsA DeltachsC double mutant (DeltaAC mutant) along with the localization of ChsA and ChsC. In the lateral cell wall of the DeltaAC mutant, electron-transparent regions were thickened. Septa of the DeltaAC mutant were aberrantly thick and had a large pore. Some septa were located abnormally close to adjacent septa. A functional hemagglutinin (HA)-tagged ChsA (HA-ChsA) and a functional FLAG-tagged ChsC (FLAG-ChsC) were each localized to a subset of septation sites. Comparison with the localization pattern of actin, which is known to localize at forming septa, suggested that ChsA and ChsC transiently exist at the septation sites during and shortly after septum formation. Double staining of HA-ChsA and FLAG-ChsC indicated that their localizations were not identical but partly overlapped at the septation sites. Fluorescence of FLAG-ChsC, but not of HA-ChsA, was also observed at hyphal tips. These data indicate that ChsA and ChsC share overlapping roles in septum formation.
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Affiliation(s)
- Masayuki Ichinomiya
- Department of Biotechnology, Department of Agricultural and Environmental Biology, The University of Tokyo, Tokyo 113-8657, Japan
| | - Emi Yamada
- Department of Biotechnology, Department of Agricultural and Environmental Biology, The University of Tokyo, Tokyo 113-8657, Japan
| | - Shuichi Yamashita
- Department of Biotechnology, Department of Agricultural and Environmental Biology, The University of Tokyo, Tokyo 113-8657, Japan
| | - Akinori Ohta
- Department of Biotechnology, Department of Agricultural and Environmental Biology, The University of Tokyo, Tokyo 113-8657, Japan
| | - Hiroyuki Horiuchi
- Department of Biotechnology, Department of Agricultural and Environmental Biology, The University of Tokyo, Tokyo 113-8657, Japan
- Corresponding author. Mailing address: 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan. Phone: 81-3-5841-5170. Fax: 81-3-5841-8015. E-mail:
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47
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Abstract
This report presents an initial comparison of motor, neck, and tail domains of myosin genes in Tetrahymena thermophila. An unrooted phylogenetic tree drawn from alignment of predicted amino acid translations determined the relationship among 13 myosins in Tetrahymena and their relationship to the myosin superfamily. The myosins in Tetrahymena did not align with any of the previously named myosin classes. Twelve of the Tetrahymena myosins form a new class designated as XX. The other Tetrahymena myosin is divergent from the twelve. Surprisingly, none of the myosins in Tetrahymena aligned with either class I, class II, or class V myosins. Apparent absence of a class II myosin is an indication that cytokinesis in Tetrahymena either utilizes an unconventional myosin or does not require a myosin motor.
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Affiliation(s)
- Selwyn A Williams
- Department of Biology, Brooklyn College of the City University of New York, Brooklyn, NY 11210, USA
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48
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Lee JI, Yu YM, Rho YM, Park BC, Choi JH, Park HM, Maeng PJ. Differential expression of thechsEgene encoding a chitin synthase ofAspergillus nidulansin response to developmental status and growth conditions. FEMS Microbiol Lett 2005; 249:121-9. [PMID: 16006063 DOI: 10.1016/j.femsle.2005.06.006] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2005] [Accepted: 06/03/2005] [Indexed: 11/13/2022] Open
Abstract
Expression of chsE encoding one of the five chitin synthases of Aspergillus nidulans was analyzed. Expression of chsE was moderate in conidiophores, but somewhat weaker in vegetative mycelia. During sexual development, chsE was expressed strongly in young cleistothecia and hülle cells, but little in mature sexual structures. Deletion of chsE caused a significant decrease in the chitin content of the cell wall during early sexual development. Expression of chsE was increased by substituting glucose with lactose or by addition of 0.6M KCl or NaCl, but affected little by substituting glucose with sodium acetate. Consequently, chsE was shown to have a mode of expression distinct from those of the other chitin synthase genes, chsA, chsB and chsC.
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Affiliation(s)
- Jeong Im Lee
- Department of Microbiology, School of Bioscience & Biotechnology, Chungnam National University, Daejeon 305-764, Republic of Korea
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49
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Takeshita N, Ohta A, Horiuchi H. CsmA, a class V chitin synthase with a myosin motor-like domain, is localized through direct interaction with the actin cytoskeleton in Aspergillus nidulans. Mol Biol Cell 2005; 16:1961-70. [PMID: 15703213 PMCID: PMC1073675 DOI: 10.1091/mbc.e04-09-0761] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
One of the essential features of fungal morphogenesis is the polarized synthesis of cell wall components such as chitin. The actin cytoskeleton provides the structural basis for cell polarity in Aspergillus nidulans, as well as in most other eukaryotes. A class V chitin synthase, CsmA, which contains a myosin motor-like domain (MMD), is conserved among most filamentous fungi. The DeltacsmA null mutant showed remarkable abnormalities with respect to cell wall integrity and the establishment of polarity. In this study, we demonstrated that CsmA tagged with 9x HA epitopes localized near actin structures at the hyphal tips and septation sites and that its MMD was able to bind to actin. Characterization of mutants bearing a point mutation or deletion in the MMD suggests that the interaction between the MMD and actin is not only necessary for the proper localization of CsmA, but also for CsmA function. Thus, the finding of a direct interaction between the chitin synthase and the actin cytoskeleton provides new insight into the mechanisms of polarized cell wall synthesis and fungal morphogenesis.
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50
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Liu H, Kauffman S, Becker JM, Szaniszlo PJ. Wangiella (Exophiala) dermatitidis WdChs5p, a class V chitin synthase, is essential for sustained cell growth at temperature of infection. EUKARYOTIC CELL 2004; 3:40-51. [PMID: 14871935 PMCID: PMC329517 DOI: 10.1128/ec.3.1.40-51.2004] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The chitin synthase structural gene WdCHS5 was isolated from the black fungal pathogen of humans Wangiella dermatitidis. Sequence analysis revealed that the gene has a myosin motor-like-encoding region at its 5' end and a chitin synthase (class V)-encoding region at its 3' end. Northern blotting showed that WdCHS5 is expressed at high levels under conditions of stress. Analysis of the 5' upstream region of WdCHS5 fused to a reporter gene indicated that one or more of the potential regulatory elements present may have contributed to the high expression levels. Disruption of WdCHS5 produced mutants that grow normally at 25 degrees C but have severe growth and cellular abnormalities at 37 degrees C. Osmotic stabilizers, such as sorbitol and sucrose, rescued the wild-type phenotype, which indicated that the loss of WdChs5p causes cell wall integrity defects. Animal survival tests with a mouse model of acute infection showed that all wdchs5Delta mutants are less virulent than the parental strain. Reintroduction of the WdCHS5 gene into the wdchs5Delta mutants abolished the temperature-sensitive phenotype and reestablished their virulence. We conclude that the product of WdCHS5 is required for the sustained growth of W. dermatitidis at 37 degrees C and is of critical importance to its virulence.
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Affiliation(s)
- Hongbo Liu
- Section of Molecular Genetics and Microbiology, School of Biological Science and Institute of Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas 78712, USA
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