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Zheng H, Guo Z, Xi Y, Yuan M, Lin Y, Wu C, Abubakar YS, Dou X, Li G, Wang Z, Zheng W, Zhou J. Sorting nexin (MoVps17) is required for fungal development and plant infection by regulating endosome dynamics in the rice blast fungus. Environ Microbiol 2017; 19:4301-4317. [PMID: 28836715 DOI: 10.1111/1462-2920.13896] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Revised: 08/16/2017] [Accepted: 08/17/2017] [Indexed: 02/05/2023]
Abstract
Vps17 is a sorting nexin (SNX) and a component of the retromer, a protein complex mediating retrograde vesicle transport between endosomes and the trans-Golgi network. However, its role in the development and pathogenicity of filamentous fungi such as the rice blast fungus (Magnaporthe oryzae) remains unclear. We investigate the functional relationship between the SNX and the cargo-selective complex (CSC) of the fungal retromer by genetic analysis, live cell imaging and immunological assay. Our data show that the MoVps17 null mutation causes defects in growth, development and pathogenicity in M. oryzae. MoVps17 is localized to endosomes depending on the activity of phosphatidylinositol 3-kinase (PI3K), a key enzyme for fungal development and infection. Both PX and BAR domains of MoVps17 are essential for its endosomal localization and function. Furthermore, our yeast two-hybrid assays show that MoVps17 and MoVps5 can interact. Lastly, live cell imaging suggests that MoVps17 can regulate early endosome fusion and budding as well as endocytosis. Taken together, our results suggest that MoVps17 specifically functions as a retromer component with CSC and also plays a distinct role in the regulation of endosome dynamics during fungal development and plant infection.
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Affiliation(s)
- Huawei Zheng
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Zhongkun Guo
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Yang Xi
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Mingyue Yuan
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Yahong Lin
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Congxian Wu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Yakubu Saddeeq Abubakar
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Xianying Dou
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Guangpu Li
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, USA
| | - Zonghua Wang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, China.,College of Ocean Science, Minjiang University, Fuzhou 350108, China
| | - Wenhui Zheng
- Key Laboratory of Biopesticides and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Jie Zhou
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, China
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Role of HxkC, a mitochondrial hexokinase-like protein, in fungal programmed cell death. Fungal Genet Biol 2016; 97:36-45. [DOI: 10.1016/j.fgb.2016.11.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Revised: 11/03/2016] [Accepted: 11/05/2016] [Indexed: 11/21/2022]
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Katz ME, Buckland R, Hunter CC, Todd RB. Distinct roles for the p53-like transcription factor XprG and autophagy genes in the response to starvation. Fungal Genet Biol 2015; 83:10-18. [DOI: 10.1016/j.fgb.2015.08.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 08/13/2015] [Accepted: 08/17/2015] [Indexed: 12/21/2022]
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The Aspergillus nidulans ATM kinase regulates mitochondrial function, glucose uptake and the carbon starvation response. G3-GENES GENOMES GENETICS 2014; 4:49-62. [PMID: 24192833 PMCID: PMC3887539 DOI: 10.1534/g3.113.008607] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Mitochondria supply cellular energy and also perform a role in the adaptation to metabolic stress. In mammals, the ataxia-telangiectasia mutated (ATM) kinase acts as a redox sensor controlling mitochondrial function. Subsequently, transcriptomic and genetic studies were utilized to elucidate the role played by a fungal ATM homolog during carbon starvation. In Aspergillus nidulans, AtmA was shown to control mitochondrial function and glucose uptake. Carbon starvation responses that are regulated by target of rapamycin (TOR) were shown to be AtmA-dependent, including autophagy and hydrolytic enzyme secretion. AtmA also regulated a p53-like transcription factor, XprG, inhibiting starvation-induced XprG-dependent protease secretion and cell death. Thus, AtmA possibly represents a direct or indirect link between mitochondrial stress, metabolism, and growth through the influence of TOR and XprG function. The coordination of cell growth and division with nutrient availability is crucial for all microorganisms to successfully proliferate in a heterogeneous environment. Mitochondria supply cellular energy but also perform a role in the adaptation to metabolic stress and the cross-talk between prosurvival and prodeath pathways. The present study of Aspergillus nidulans demonstrated that AtmA also controlled mitochondrial mass, function, and oxidative phosphorylation, which directly or indirectly influenced glucose uptake. Carbon starvation responses, including autophagy, shifting metabolism to the glyoxylate cycle, and the secretion of carbon scavenging enzymes were AtmA-dependent. Transcriptomic profiling of the carbon starvation response demonstrated how TOR signaling and the retrograde response, which signals mitochondrial dysfunction, were directly or indirectly influenced by AtmA. The AtmA kinase was also shown to influence a p53-like transcription factor, inhibiting starvation-induced XprG-dependent protease secretion and cell death. Therefore, in response to metabolic stress, AtmA appears to perform a role in the regulation of TOR signaling, involving the retrograde and SnfA pathways. Thus, AtmA may represent a link between mitochondrial function and cell cycle or growth, possibly through the influence of the TOR and XprG function.
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Katz ME, Braunberger K, Yi G, Cooper S, Nonhebel HM, Gondro C. A p53-like transcription factor similar to Ndt80 controls the response to nutrient stress in the filamentous fungus, Aspergillus nidulans. F1000Res 2013; 2:72. [PMID: 24358888 PMCID: PMC3821154 DOI: 10.12688/f1000research.2-72.v1] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/28/2013] [Indexed: 12/11/2022] Open
Abstract
The
Aspergillus nidulans xprG gene encodes a putative transcriptional activator that is a member of the Ndt80 family in the p53-like superfamily of proteins. Previous studies have shown that XprG controls the production of extracellular proteases in response to starvation. We undertook transcriptional profiling to investigate whether XprG has a wider role as a global regulator of the carbon nutrient stress response. Our microarray data showed that the expression of a large number of genes, including genes involved in secondary metabolism, development, high-affinity glucose uptake and autolysis, were altered in an
xprGΔ null mutant. Many of these genes are known to be regulated in response to carbon starvation. We confirmed that sterigmatocystin and penicillin production is reduced in
xprG
- mutants. The loss of fungal mass and secretion of pigments that accompanies fungal autolysis in response to nutrient depletion was accelerated in an
xprG1 gain-of-function mutant and decreased or absent in an
xprG
- mutant. The results support the hypothesis that XprG plays a major role in the response to carbon limitation and that nutrient sensing may represent one of the ancestral roles for the p53-like superfamily. Disruption of the AN6015 gene, which encodes a second Ndt80-like protein, showed that it is required for sexual reproduction in
A. nidulans.
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Affiliation(s)
- Margaret E Katz
- Department of Molecular and Cellular Biology, University of New England, Armidale, NSW 2351, Australia
| | - Kathryn Braunberger
- Department of Molecular and Cellular Biology, University of New England, Armidale, NSW 2351, Australia
| | - Gauncai Yi
- Department of Molecular and Cellular Biology, University of New England, Armidale, NSW 2351, Australia ; Current address: Nanjing Hospital for Women & Children's Health, Nanjing Medical University, Nanjing City, 210004, China
| | - Sarah Cooper
- Department of Molecular and Cellular Biology, University of New England, Armidale, NSW 2351, Australia
| | - Heather M Nonhebel
- Department of Molecular and Cellular Biology, University of New England, Armidale, NSW 2351, Australia
| | - Cedric Gondro
- The Centre for Genetic Analysis and Applications, University of New England, Armidale, NSW 2351, Australia
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Szilágyi M, Kwon NJ, Bakti F, M-Hamvas M, Jámbrik K, Park H, Pócsi I, Yu JH, Emri T. Extracellular proteinase formation in carbon starving Aspergillus nidulans cultures--physiological function and regulation. J Basic Microbiol 2011; 51:625-34. [PMID: 21953444 DOI: 10.1002/jobm.201100068] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Accepted: 05/24/2011] [Indexed: 11/09/2022]
Abstract
Extracellular proteinase formation in carbon depleted cultures of the model filamentous fungus Aspergillus nidulans was studied to elucidate its regulation and possible physiological function. As demonstrated by gene deletion, culture optimization, microbial physiological and enzymological experiments, the PrtA and PepJ proteinases of A. nidulans did not appear to play a decisive role in the autolytic decomposition of fungal cells under the conditions we tested. However, carbon starvation induced formation of the proteinases observable in autolytic cultures. Similar to other degradative enzymes, production of proteinase was regulated by FluG-BrlA asexual developmental signaling and modulated by PacC-dependent pH-responsive signaling. Under the same carbon starved culture conditions, alterations of CreA, MeaB or heterotrimeric G protein mediated signaling pathways caused less significant changes in the formation of extracellular proteinases. Taken together, these results indicate that while the accumulation of PrtA and PepJ is tightly coupled to the initiation of autolysis, they are not essential for autolytic cell wall degradation in A. nidulans. Thus, as Aspergillus genomes contain a large group of genes encoding proteinases with versatile physiological functions, selective control of proteinase production in fungal cells is needed for the improved industrial use of fungi.
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Affiliation(s)
- Melinda Szilágyi
- Department of Microbial Biotechnology and Cell Biology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
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Fungal proteases and their pathophysiological effects. Mycopathologia 2011; 171:299-323. [PMID: 21259054 DOI: 10.1007/s11046-010-9386-2] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2010] [Accepted: 12/02/2010] [Indexed: 12/14/2022]
Abstract
Proteolytic enzymes play an important role in fungal physiology and development. External digestion of protein substrates by secreted proteases is required for survival and growth of both saprophytic and pathogenic species. Extracellular serine, aspartic, and metalloproteases are considered virulence factors of many pathogenic species. New findings focus on novel membrane-associated proteases such as yapsins and ADAMs and their role in pathology. Proteases from fungi induce inflammatory responses by altering the permeability of epithelial barrier and by induction of proinflammatory cytokines through protease-activated receptors. Many fungal allergens possess proteolytic activity that appears to be essential in eliciting Th2 responses. Allergenic fungal proteases can act as adjuvants, potentiating responses to other allergens. Proteolytic enzymes from fungi contribute to inflammation through interactions with the kinin system as well as the coagulation and fibrinolytic cascades. Their effect on the host protease-antiprotease balance results from activation of endogenous proteases and degradation of protease inhibitors. Recent studies of the role of fungi in human health point to the growing importance of proteases not only as pathogenic agents in fungal infections but also in asthma, allergy, and damp building related illnesses. Proteolytic enzymes from fungi are widely used in biotechnology, mainly in food, leather, and detergent industries, in ecological bioremediation processes and to produce therapeutic peptides. The involvement of fungal proteases in diverse pathological mechanisms makes them potential targets of therapeutic intervention and candidates for biomarkers of disease and exposure.
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