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Li N, Zeng Y, Chen Y, Shen Y, Wang W. Induction of cellulase production by Sr 2+ in Trichoderma reesei via calcium signaling transduction. BIORESOUR BIOPROCESS 2022; 9:96. [PMID: 38647894 PMCID: PMC10992071 DOI: 10.1186/s40643-022-00587-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Accepted: 08/28/2022] [Indexed: 11/10/2022] Open
Abstract
Trichoderma reesei RUT-C30 is a well-known high-yielding cellulase-producing fungal strain that converts lignocellulose into cellulosic sugar for resource regeneration. Calcium is a ubiquitous secondary messenger that regulates growth and cellulase production in T. reesei. We serendipitously found that adding Sr2+ to the medium significantly increased cellulase activity in the T. reesei RUT-C30 strain and upregulated the expression of cellulase-related genes. Further studies showed that Sr2+ supplementation increased the cytosolic calcium concentration and activated the calcium-responsive signal transduction pathway of Ca2+-calcineurin-responsive zinc finger transcription factor 1 (CRZ1). Using the plasma membrane Ca2+ channel blocker, LaCl3, we demonstrated that Sr2+ induces cellulase production via the calcium signaling pathway. Supplementation with the corresponding concentrations of Sr2+ also inhibited colony growth. Sr2+ supplementation led to an increase in intracellular reactive oxygen species (ROS) and upregulated the transcriptional levels of intracellular superoxide dismutase (sod1) and catalase (cat1). We further demonstrated that ROS content was detrimental to cellulase production, which was alleviated by the ROS scavenger N-acetyl cysteine (NAC). This study demonstrated for the first time that Sr2+ supplementation stimulates cellulase production and upregulates cellulase genes via the calcium signaling transduction pathway. Sr2+ leads to an increase in intracellular ROS, which is detrimental to cellulase production and can be alleviated by the ROS scavenger NAC. Our results provide insights into the mechanistic study of cellulase synthesis and the discovery of novel inducers of cellulase.
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Affiliation(s)
- Ni Li
- The State Key Laboratory of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, Shanghai, 200237, China
| | - Yi Zeng
- The State Key Laboratory of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, Shanghai, 200237, China
| | - Yumeng Chen
- The State Key Laboratory of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, Shanghai, 200237, China
| | - Yaling Shen
- The State Key Laboratory of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, Shanghai, 200237, China
| | - Wei Wang
- The State Key Laboratory of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, Shanghai, 200237, China.
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Liu C, Liu T, Lv Z, Qin M, Qu Z, Zhang Z, Li F, Chen D, Zhang X, Chen XL, Shen M. A Calcineurin Regulator MoRCN1 Is Important for Asexual Development, Stress Response, and Plant Infection of Magnaporthe oryzae. FRONTIERS IN PLANT SCIENCE 2022; 13:925645. [PMID: 35783935 PMCID: PMC9244802 DOI: 10.3389/fpls.2022.925645] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 05/05/2022] [Indexed: 06/12/2023]
Abstract
The calcium/calcineurin signaling pathway plays a key role in the development and virulence of plant pathogenic fungi, but the regulation of this signaling pathway is still not clear. In this study, we identified a calcineurin regulator MoRCN1 in the plant pathogenic fungus Magnaporthe oryzae and found it is important for virulence by regulating the calcineurin pathway. MoRCN1 deletion mutants were severely decreased in colony growth and conidia formation. More importantly, the deletion of MoRCN1 led to a significant reduction in virulence due to defects in appressorium formation and invasive growth. The ΔMorcn1 mutants were more sensitive to different stresses and induced host ROS accumulation, suggesting a role of MoRCN1 in stress adaptation. We found that MoRCN1 directly interacted with the calcineurin catalytic subunit MoCNA and affected its protein stability, which was therefore important for regulating the calcineurin pathway. Transcriptome analysis showed that MoRCN1 significantly activated 491 genes and suppressed 337 genes in response to calcium ion, partially overlapped with the MoCRZ1-bound genes. Gene Ontology and KEGG pathway analyses indicated that MoRCN1-regulated genes were enriched in stress adaptation, lipid metabolism, and secondary metabolite biosynthesis, reflecting a function of MoRCN1 in host cell adaptation. Altogether, these results suggest MoRCN1 functions as a regulator of the calcium/calcineurin signaling pathway for fungal development and infection of host cells.
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Affiliation(s)
- Caiyun Liu
- Hubei Key Laboratory of Economic Forest Germplasm Improvement and Resources Comprehensive Utilization, College of Biology and Agricultural Resources, Huanggang Normal University, Huanggang, China
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Tiangu Liu
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Ziwei Lv
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Mengyuan Qin
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Zhiguang Qu
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Ziwei Zhang
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Fuyan Li
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Deng Chen
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Xinrong Zhang
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Xiao-Lin Chen
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Mi Shen
- Hubei Key Laboratory of Economic Forest Germplasm Improvement and Resources Comprehensive Utilization, College of Biology and Agricultural Resources, Huanggang Normal University, Huanggang, China
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Dzurendova S, Zimmermann B, Kohler A, Reitzel K, Nielsen UG, Dupuy--Galet BX, Leivers S, Horn SJ, Shapaval V. Calcium Affects Polyphosphate and Lipid Accumulation in Mucoromycota Fungi. J Fungi (Basel) 2021; 7:jof7040300. [PMID: 33920847 PMCID: PMC8071181 DOI: 10.3390/jof7040300] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/08/2021] [Accepted: 04/12/2021] [Indexed: 12/11/2022] Open
Abstract
Calcium controls important processes in fungal metabolism, such as hyphae growth, cell wall synthesis, and stress tolerance. Recently, it was reported that calcium affects polyphosphate and lipid accumulation in fungi. The purpose of this study was to assess the effect of calcium on the accumulation of lipids and polyphosphate for six oleaginous Mucoromycota fungi grown under different phosphorus/pH conditions. A Duetz microtiter plate system (Duetz MTPS) was used for the cultivation. The compositional profile of the microbial biomass was recorded using Fourier-transform infrared spectroscopy, the high throughput screening extension (FTIR-HTS). Lipid content and fatty acid profiles were determined using gas chromatography (GC). Cellular phosphorus was determined using assay-based UV-Vis spectroscopy, and accumulated phosphates were characterized using solid-state 31P nuclear magnetic resonance spectroscopy. Glucose consumption was estimated by FTIR-attenuated total reflection (FTIR-ATR). Overall, the data indicated that calcium availability enhances polyphosphate accumulation in Mucoromycota fungi, while calcium deficiency increases lipid production, especially under acidic conditions (pH 2-3) caused by the phosphorus limitation. In addition, it was observed that under acidic conditions, calcium deficiency leads to increase in carotenoid production. It can be concluded that calcium availability can be used as an optimization parameter in fungal fermentation processes to enhance the production of lipids or polyphosphates.
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Affiliation(s)
- Simona Dzurendova
- Faculty of Science and Technology, Norwegian University of Life Sciences, Drøbakveien 31, 1433 Ås, Norway; (B.Z.); (A.K.); (B.X.D.--G.); (V.S.)
- Correspondence: or
| | - Boris Zimmermann
- Faculty of Science and Technology, Norwegian University of Life Sciences, Drøbakveien 31, 1433 Ås, Norway; (B.Z.); (A.K.); (B.X.D.--G.); (V.S.)
| | - Achim Kohler
- Faculty of Science and Technology, Norwegian University of Life Sciences, Drøbakveien 31, 1433 Ås, Norway; (B.Z.); (A.K.); (B.X.D.--G.); (V.S.)
| | - Kasper Reitzel
- Department of Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark;
| | - Ulla Gro Nielsen
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark;
| | - Benjamin Xavier Dupuy--Galet
- Faculty of Science and Technology, Norwegian University of Life Sciences, Drøbakveien 31, 1433 Ås, Norway; (B.Z.); (A.K.); (B.X.D.--G.); (V.S.)
| | - Shaun Leivers
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Christian Magnus Falsens vei 1, 1433 Ås, Norway; (S.L.); (S.J.H.)
| | - Svein Jarle Horn
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Christian Magnus Falsens vei 1, 1433 Ås, Norway; (S.L.); (S.J.H.)
| | - Volha Shapaval
- Faculty of Science and Technology, Norwegian University of Life Sciences, Drøbakveien 31, 1433 Ås, Norway; (B.Z.); (A.K.); (B.X.D.--G.); (V.S.)
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Chen Y, Fan X, Zhao X, Shen Y, Xu X, Wei L, Wang W, Wei D. cAMP activates calcium signalling via phospholipase C to regulate cellulase production in the filamentous fungus Trichoderma reesei. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:62. [PMID: 33685506 PMCID: PMC7941909 DOI: 10.1186/s13068-021-01914-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 02/21/2021] [Indexed: 05/15/2023]
Abstract
BACKGROUND The filamentous fungus Trichoderma reesei is one of the best producers of cellulase and has been widely studied for the production of cellulosic ethanol and bio-based products. We previously reported that Mn2+ and N,N-dimethylformamide (DMF) can stimulate cellulase overexpression via Ca2+ bursts and calcium signalling in T. reesei under cellulase-inducing conditions. To further understand the regulatory networks involved in cellulase overexpression in T. reesei, we characterised the Mn2+/DMF-induced calcium signalling pathway involved in the stimulation of cellulase overexpression. RESULTS We found that Mn2+/DMF stimulation significantly increased the intracellular levels of cAMP in an adenylate cyclase (ACY1)-dependent manner. Deletion of acy1 confirmed that cAMP is crucial for the Mn2+/DMF-stimulated cellulase overexpression in T. reesei. We further revealed that cAMP elevation induces a cytosolic Ca2+ burst, thereby initiating the Ca2+ signal transduction pathway in T. reesei, and that cAMP signalling causes the Ca2+ signalling pathway to regulate cellulase production in T. reesei. Furthermore, using a phospholipase C encoding gene plc-e deletion strain, we showed that the plc-e gene is vital for cellulase overexpression in response to stimulation by both Mn2+ and DMF, and that cAMP induces a Ca2+ burst through PLC-E. CONCLUSIONS The findings of this study reveal the presence of a signal transduction pathway in which Mn2+/DMF stimulation produces cAMP. Increase in the levels of cAMP activates the calcium signalling pathway via phospholipase C to regulate cellulase overexpression under cellulase-inducing conditions. These findings provide insights into the molecular mechanism of the cAMP-PLC-calcium signalling pathway underlying cellulase expression in T. reesei and highlight the potential applications of signal transduction in the regulation of gene expression in fungi.
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Affiliation(s)
- Yumeng Chen
- State Key Lab of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, 130 Meilong Road , P.O.B. 311, Shanghai, 200237, China
| | - Xingjia Fan
- State Key Lab of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, 130 Meilong Road , P.O.B. 311, Shanghai, 200237, China
| | - Xinqing Zhao
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Yaling Shen
- State Key Lab of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, 130 Meilong Road , P.O.B. 311, Shanghai, 200237, China
| | - Xiangyang Xu
- Zaozhuang Jie Nuo Enzyme Co. Ltd., Shandong, China
| | - Liujing Wei
- State Key Lab of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, 130 Meilong Road , P.O.B. 311, Shanghai, 200237, China
| | - Wei Wang
- State Key Lab of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, 130 Meilong Road , P.O.B. 311, Shanghai, 200237, China.
| | - Dongzhi Wei
- State Key Lab of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, 130 Meilong Road , P.O.B. 311, Shanghai, 200237, China
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Tian T, Zhang B, Chen S, Tao T, Liu Q, Liu B, Yuan J, Ding C. Characterization of differences between microwave and traditional thermal sterilization to prevent fungal spoilage during storage of high‐moisture paddy rice. Cereal Chem 2020. [DOI: 10.1002/cche.10331] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Tian Tian
- College of Food Science and Engineering Collaborative Innovation Center for Modern Grain Circulation and Safety Key Laboratory of Grains and Oils Quality Control and Processing Nanjing University of Finance and Economics Nanjing China
| | - Bin Zhang
- College of Food Science and Engineering Collaborative Innovation Center for Modern Grain Circulation and Safety Key Laboratory of Grains and Oils Quality Control and Processing Nanjing University of Finance and Economics Nanjing China
| | - Shangbing Chen
- College of Food Science and Engineering Collaborative Innovation Center for Modern Grain Circulation and Safety Key Laboratory of Grains and Oils Quality Control and Processing Nanjing University of Finance and Economics Nanjing China
| | - Tingting Tao
- Institute of Food Safety and Nutrition Jiangsu Academy of Agricultural Sciences Nanjing China
| | - Qiang Liu
- College of Food Science and Engineering Collaborative Innovation Center for Modern Grain Circulation and Safety Key Laboratory of Grains and Oils Quality Control and Processing Nanjing University of Finance and Economics Nanjing China
| | - Bing Liu
- College of Food Science and Engineering Collaborative Innovation Center for Modern Grain Circulation and Safety Key Laboratory of Grains and Oils Quality Control and Processing Nanjing University of Finance and Economics Nanjing China
| | - Jian Yuan
- College of Food Science and Engineering Collaborative Innovation Center for Modern Grain Circulation and Safety Key Laboratory of Grains and Oils Quality Control and Processing Nanjing University of Finance and Economics Nanjing China
| | - Chao Ding
- College of Food Science and Engineering Collaborative Innovation Center for Modern Grain Circulation and Safety Key Laboratory of Grains and Oils Quality Control and Processing Nanjing University of Finance and Economics Nanjing China
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Li X, Huang L, He Y, Xie C, Zhan F, Zu Y, Sheng J, Li Y. Effects of enhanced UV-B radiation on the interaction between rice and Magnaporthe oryzae in Yuanyang terrace. Photochem Photobiol Sci 2019; 18:2965-2976. [PMID: 31657369 DOI: 10.1039/c8pp00556g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Enhanced ultraviolet-B (UV-B) radiation affected the growth of rice and Magnaporthe oryzae, and changed the interactions between them. Increased UV-B radiation (5.0 kJ m-2 d-1) on rice leaves in a Yuanyang terrace was conducted before, during, and after infection of the leaves with Magnaporthe oryzae. The relationship between rice blast and UV-B radiation on the disease resistance of rice and the pathogenicity of M. oryzae was studied, and the effects of enhanced UV-B radiation on the interactions between rice and M. oryzae were analysed. The results indicated the following: (1) enhanced UV-B radiation significantly reduced the rice blast disease index, but as infection progressed, the inhibitory effect of UV-B radiation on the disease was weakened. (2) UV-B radiation treatment before infection with M. oryzae (UV-B + M.) significantly increased the activity of the enzymes related to disease resistance (phenylalanine ammonia lyase, lipoxygenase, chitinase, and β-1,3-glucanase), and the plants exhibited light-induced resistance. (3) Exposure to UV-B radiation after M. oryzae infection (M. + UV-B) did not induce disease course-related protein (PR) activity, but the content of soluble sugar increased. The osmotic stress caused by pathogenic fungi infection was alleviated by active accumulation of soluble sugar; due to this lack of nutrients, it was difficult for the rice blast fungus to grow. (4) Enhanced UV-B radiation significantly inhibited the production of conidia by M. oryzae, and the expression of the pathogenic genes Chitinase, MGP1, MAGB, and CPKA was significantly downregulated. The pathogenicity of M. oryzae was reduced by UV-B radiation. The resistance of rice leaves was weakened by simultaneous exposure to UV-B radiation and M. oryzae (UV-B/M.). Hence, UV-B radiation can weaken the infectivity of M. oryzae, improve the resistance of traditional rice, and contain the disease.
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Affiliation(s)
- Xiang Li
- College of Resources and Environment, Yunnan Agricultural University, Kunming, 650201, China.
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Lee CG, Koo JC, Park JK. Antifungal Effect of Chitosan as Ca(2+) Channel Blocker. THE PLANT PATHOLOGY JOURNAL 2016; 32:242-250. [PMID: 27298599 PMCID: PMC4892820 DOI: 10.5423/ppj.oa.08.2015.0162] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 02/06/2016] [Accepted: 02/15/2016] [Indexed: 06/06/2023]
Abstract
The aim of this study was to investigate antifungal activity of a range of different molecular weight (MW) chitosan against Penicillium italicum. Our results demonstrate that the antifungal activity was dependent both the MW and concentration of the chitosan. Among a series of chitosan derived from the hydrolysis of high MW chitosan, the fractions containing various sizes of chitosan ranging from 3 to 15 glucosamine units named as chitooligomers-F2 (CO-F2) was found to show the highest antifungal activity against P. italicum. Furthermore, the effect of CO-F2 toward this fungus was significantly reduced in the presence of Ca(2+), whereas its effect was recovered by ethylenediaminetetraacetic acid, suggesting that the CO-F2 acts via disruption of Ca(2+) gradient required for survival of the fungus. Our results suggest that CO-F2 may serve as potential compounds to develop alternatives to synthetic fungicides for the control of the postharvest diseases.
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Affiliation(s)
- Choon Geun Lee
- Department of Life Science, College of BioNano, Gachon University, Seongnam 13120,
Korea
| | - Ja Choon Koo
- Division of Science Education and Institute of Fusion Science, Chonbuk National University, Jeonju 54896,
Korea
| | - Jae Kweon Park
- Department of Life Science, College of BioNano, Gachon University, Seongnam 13120,
Korea
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Salvioli A, Ghignone S, Novero M, Navazio L, Venice F, Bagnaresi P, Bonfante P. Symbiosis with an endobacterium increases the fitness of a mycorrhizal fungus, raising its bioenergetic potential. THE ISME JOURNAL 2016; 10:130-44. [PMID: 26046255 PMCID: PMC4681866 DOI: 10.1038/ismej.2015.91] [Citation(s) in RCA: 139] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 03/27/2015] [Accepted: 04/21/2015] [Indexed: 01/08/2023]
Abstract
Arbuscular mycorrhizal fungi (AMF) occur in the rhizosphere and in plant tissues as obligate symbionts, having key roles in plant evolution and nutrition. AMF possess endobacteria, and genome sequencing of the endobacterium Candidatus Glomeribacter gigasporarum revealed a reduced genome and a dependence on the fungal host. To understand the effect of bacteria on fungal fitness, we used next-generation sequencing to analyse the transcriptional profile of Gigaspora margarita in the presence and in the absence of its endobacterium. Genomic data on AMF are limited; therefore, we first generated a gene catalogue for G. margarita. Transcriptome analysis revealed that the endobacterium has a stronger effect on the pre-symbiotic phase of the fungus. Coupling transcriptomics with cell biology and physiological approaches, we demonstrate that the bacterium increases the fungal sporulation success, raises the fungal bioenergetic capacity, increasing ATP production, and eliciting mechanisms to detoxify reactive oxygen species. By using TAT peptide to translocate the bioluminescent calcium reporter aequorin, we demonstrated that the line with endobacteria had a lower basal intracellular calcium concentration than the cured line. Lastly, the bacteria seem to enhance the fungal responsiveness to strigolactones, the plant molecules that AMF perceive as branching factors. Although the endobacterium exacts a nutritional cost on the AMF, endobacterial symbiosis improves the fungal ecological fitness by priming mitochondrial metabolic pathways and giving the AMF more tools to face environmental stresses. Thus, we hypothesise that, as described for the human microbiota, endobacteria may increase AMF innate immunity.
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Affiliation(s)
- Alessandra Salvioli
- Department of Life Science and Systems Biology, University of Torino, Torino, Italy
| | - Stefano Ghignone
- Institute for Sustainable Plant Protection (IPSP) – CNR, Torino, Italy
| | - Mara Novero
- Department of Life Science and Systems Biology, University of Torino, Torino, Italy
| | | | - Francesco Venice
- Department of Life Science and Systems Biology, University of Torino, Torino, Italy
| | - Paolo Bagnaresi
- Research Center for Genomics and Postgenomics, CRA-Fiorenzuola d'Arda, Italy
| | - Paola Bonfante
- Department of Life Science and Systems Biology, University of Torino, Torino, Italy
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Muñoz A, Bertuzzi M, Bettgenhaeuser J, Iakobachvili N, Bignell EM, Read ND. Different Stress-Induced Calcium Signatures Are Reported by Aequorin-Mediated Calcium Measurements in Living Cells of Aspergillus fumigatus. PLoS One 2015; 10:e0138008. [PMID: 26402916 PMCID: PMC4581630 DOI: 10.1371/journal.pone.0138008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 08/24/2015] [Indexed: 11/18/2022] Open
Abstract
Aspergillus fumigatus is an inhaled fungal pathogen of human lungs, the developmental growth of which is reliant upon Ca2+-mediated signalling. Ca2+ signalling has regulatory significance in all eukaryotic cells but how A. fumigatus uses intracellular Ca2+ signals to respond to stresses imposed by the mammalian lung is poorly understood. In this work, A. fumigatus strains derived from the clinical isolate CEA10, and a non-homologous recombination mutant ΔakuBKU80, were engineered to express the bioluminescent Ca2+-reporter aequorin. An aequorin-mediated method for routine Ca2+ measurements during the early stages of colony initiation was successfully developed and dynamic changes in cytosolic free calcium ([Ca2+]c) in response to extracellular stimuli were measured. The response to extracellular challenges (hypo- and hyper-osmotic shock, mechanical perturbation, high extracellular Ca2+, oxidative stress or exposure to human serum) that the fungus might be exposed to during infection, were analysed in living conidial germlings. The 'signatures' of the transient [Ca2+]c responses to extracellular stimuli were found to be dose- and age-dependent. Moreover, Ca2+-signatures associated with each physico-chemical treatment were found to be unique, suggesting the involvement of heterogeneous combinations of Ca2+-signalling components in each stress response. Concordant with the involvement of Ca2+-calmodulin complexes in these Ca2+-mediated responses, the calmodulin inhibitor trifluoperazine (TFP) induced changes in the Ca2+-signatures to all the challenges. The Ca2+-chelator BAPTA potently inhibited the initial responses to most stressors in accordance with a critical role for extracellular Ca2+ in initiating the stress responses.
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Affiliation(s)
- Alberto Muñoz
- Manchester Fungal Infection Group, Institute of Inflammation and Repair, University of Manchester, Manchester, United Kingdom
- Fungal Cell Biology Group, Institute of Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Margherita Bertuzzi
- Manchester Fungal Infection Group, Institute of Inflammation and Repair, University of Manchester, Manchester, United Kingdom
- Centre for Molecular Bacteriology and Infection, Department of Medicine, Imperial College London, London, United Kingdom
| | - Jan Bettgenhaeuser
- Fungal Cell Biology Group, Institute of Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Nino Iakobachvili
- Centre for Molecular Bacteriology and Infection, Department of Medicine, Imperial College London, London, United Kingdom
| | - Elaine M. Bignell
- Manchester Fungal Infection Group, Institute of Inflammation and Repair, University of Manchester, Manchester, United Kingdom
- Centre for Molecular Bacteriology and Infection, Department of Medicine, Imperial College London, London, United Kingdom
- * E-mail: (NDR); (EMB)
| | - Nick D. Read
- Manchester Fungal Infection Group, Institute of Inflammation and Repair, University of Manchester, Manchester, United Kingdom
- Fungal Cell Biology Group, Institute of Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
- * E-mail: (NDR); (EMB)
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10
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Virágh M, Marton A, Vizler C, Tóth L, Vágvölgyi C, Marx F, Galgóczy L. Insight into the antifungal mechanism of Neosartorya fischeri antifungal protein. Protein Cell 2015; 6:518-28. [PMID: 25994413 PMCID: PMC4491047 DOI: 10.1007/s13238-015-0167-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 04/10/2015] [Indexed: 11/28/2022] Open
Abstract
Small, cysteine-rich, highly stable antifungal proteins secreted by filamentous Ascomycetes have great potential for the development of novel antifungal strategies. However, their practical application is still limited due to their not fully clarified mode of action. The aim of this work was to provide a deep insight into the antifungal mechanism of Neosartorya fischeri antifungal protein (NFAP), a novel representative of this protein group. Within a short exposure time to NFAP, reduced cellular metabolism, apoptosis induction, changes in the actin distribution and chitin deposition at the hyphal tip were observed in NFAP-sensitive Aspergillus nidulans. NFAP did show neither a direct membrane disrupting-effect nor uptake by endocytosis. Investigation of A. nidulans signalling mutants revealed that NFAP activates the cAMP/protein kinase A pathway via G-protein signalling which leads to apoptosis and inhibition of polar growth. In contrast, NFAP does not have any influence on the cell wall integrity pathway, but an unknown cell wall integrity pathway-independent mitogen activated protein kinase A-activated target is assumed to be involved in the cell death induction. Taken together, it was concluded that NFAP shows similarities, but also differences in its mode of antifungal action compared to two most investigated NFAP-related proteins from Aspergillus giganteus and Penicillium chrysogenum.
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Affiliation(s)
- Máté Virágh
- Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
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Binder U, Benčina M, Fizil Á, Batta G, Chhillar AK, Marx F. Protein kinase A signaling and calcium ions are major players in PAF mediated toxicity against Aspergillus niger. FEBS Lett 2015; 589:1266-71. [PMID: 25882631 PMCID: PMC4424949 DOI: 10.1016/j.febslet.2015.03.037] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Revised: 03/27/2015] [Accepted: 03/30/2015] [Indexed: 11/16/2022]
Abstract
Aspergillus niger is highly susceptible to the antifungal protein PAF. Ca2+ and cAMP/PKA signalling are interconnected in response to PAF. PAF toxicity requires the activation of the cAMP/PkaA signaling cascade. PAF evokes a sustained increase in the [Ca2+]c resting level. Only a functional PAF protein interferes with the fungal Ca2+ homeostasis. PAF represents a promising molecule to develop new antifungal strategies.
The Penicillium chrysogenum antifungal protein PAF is toxic against potentially pathogenic Ascomycetes. We used the highly sensitive aequorin-expressing model Aspergillus niger to identify a defined change in cytoplasmic free Ca2+ dynamics in response to PAF. This Ca2+ signature depended on an intact positively charged lysine-rich PAF motif. By combining Ca2+ measurements in A. niger mutants with deregulated cAMP/protein kinase A (PKA) signaling, we proved the interconnection of Ca2+ perturbation and cAMP/PKA signaling in the mechanistic function of PAF. A deep understanding of the mode of action of PAF is an invaluable prerequisite for its future application as new antifungal drug.
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Affiliation(s)
- Ulrike Binder
- Biocenter, Division of Molecular Biology, Medical University of Innsbruck, Innrain 80, A-6020 Innsbruck, Austria; Division of Hygiene and Medical Microbiology, Schöpfstrasse 41, Medical University of Innsbruck, A-6020 Innsbruck, Austria
| | - Mojca Benčina
- Department of Biotechnology, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia
| | - Ádám Fizil
- Department of Organic Chemistry, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary
| | - Gyula Batta
- Department of Organic Chemistry, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary
| | - Anil K Chhillar
- Biocenter, Division of Molecular Biology, Medical University of Innsbruck, Innrain 80, A-6020 Innsbruck, Austria; Centre for Biotechnology, Maharshi Dayanand University, IN-124001 Rohtak, Haryana, India
| | - Florentine Marx
- Biocenter, Division of Molecular Biology, Medical University of Innsbruck, Innrain 80, A-6020 Innsbruck, Austria.
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Moscatiello R, Sello S, Novero M, Negro A, Bonfante P, Navazio L. The intracellular delivery of TAT-aequorin reveals calcium-mediated sensing of environmental and symbiotic signals by the arbuscular mycorrhizal fungus Gigaspora margarita. THE NEW PHYTOLOGIST 2014; 203:1012-1020. [PMID: 24845011 DOI: 10.1111/nph.12849] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 04/10/2014] [Indexed: 06/03/2023]
Abstract
Arbuscular mycorrhiza (AM) is an ecologically relevant symbiosis between most land plants and Glomeromycota fungi. The peculiar traits of AM fungi have so far limited traditional approaches such as genetic transformation. The aim of this work was to investigate whether the protein transduction domain of the HIV-1 transactivator of transcription (TAT) protein, previously shown to act as a potent nanocarrier for macromolecule delivery in both animal and plant cells, may translocate protein cargoes into AM fungi. We evaluated the internalization into germinated spores of Gigaspora margarita of two recombinant TAT fusion proteins consisting of either a fluorescent (GFP) or a luminescent (aequorin) reporter linked to the TAT peptide. Both TAT-fused proteins were found to enter AM fungal mycelia after a short incubation period (5-10 min). Ca2+ measurements in G. margarita mycelia pre-incubated with TAT-aequorin demonstrated the occurrence of changes in the intracellular free Ca2+ concentration in response to relevant stimuli, such as touch, cold, salinity, and strigolactones, symbiosis-related plant signals. These data indicate that the cell-penetrating properties of the TAT peptide can be used as an effective strategy for intracellularly delivering proteins of interest and shed new light on Ca2+ homeostasis and signalling in AM fungi.
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Affiliation(s)
- Roberto Moscatiello
- Department of Biology, University of Padova, Via U. Bassi 58/B, 35131, Padova, Italy
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Hu S, Zhou X, Gu X, Cao S, Wang C, Xu JR. The cAMP-PKA pathway regulates growth, sexual and asexual differentiation, and pathogenesis in Fusarium graminearum. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2014; 27:557-66. [PMID: 24450772 DOI: 10.1094/mpmi-10-13-0306-r] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Like many other filamentous ascomycetes, Fusarium graminearum contains two genes named CPK1 and CPK2 that encode the catalytic subunits of cyclic AMP (cAMP)-dependent protein kinase A (PKA). To determine the role of cAMP signaling in pathogenesis and development in F. graminearum, we functionally characterized these two genes. In addition, we generated and characterized the cpk1 cpk2 double and fac1 adenylate cyclase gene deletion mutants. The cpk1 mutant was significantly reduced in vegetative growth, conidiation, and deoxynivalenol production but it had increased tolerance to elevated temperatures. It was defective in the production of penetration branches on plant surfaces, colonization of wheat rachises, and spreading in flowering wheat heads. Deletion of CPK1 had no effect on perithecium development but the cpk1 mutant was defective in ascospore maturation and releasing. In contrast, the cpk2 mutant had no detectable phenotypes, suggesting that CPK2 contributes minimally to PKA activities in F. graminearum. Nevertheless, the cpk1 cpk2 double mutant had more severe defects in vegetative growth and rarely produced morphologically abnormal conidia. The double mutant, unlike the cpk1 or cpk2 mutant, was nonpathogenic and failed to form perithecia on self-mating plates. Therefore, CPK1 and CPK2 must have overlapping functions in vegetative growth, differentiation, and plant infection in F. graminearum. The fac1 mutant was also nonpathogenic and had growth defects similar to those of the cpk1 cpk2 mutant. However, deletion of FAC1 had no effect on conidium morphology. These results indicated that CPK1 is the major PKA catalytic subunit gene and that the cAMP-PKA pathway plays critical roles in hyphal growth, conidiation, ascosporogenesis, and plant infection in F. graminearum.
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Troppens DM, Chu M, Holcombe LJ, Gleeson O, O'Gara F, Read ND, Morrissey JP. The bacterial secondary metabolite 2,4-diacetylphloroglucinol impairs mitochondrial function and affects calcium homeostasis in Neurospora crassa. Fungal Genet Biol 2013; 56:135-46. [PMID: 23624246 DOI: 10.1016/j.fgb.2013.04.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Revised: 03/25/2013] [Accepted: 04/12/2013] [Indexed: 10/26/2022]
Abstract
The bacterial secondary metabolite 2,4-diacetylphloroglucinol (DAPG) is of interest as an active ingredient of biological control strains of Pseudomonas fluorescens and as a potential lead pharmaceutical molecule because of its capacity to inhibit growth of diverse microbial and non-microbial cells. The mechanism by which this occurs is unknown and in this study the filamentous fungus Neurospora crassa was used as a model to investigate the effects of DAPG on a eukaryotic cell. Colony growth, conidial germination and cell fusion assays confirmed the inhibitory nature of DAPG towards N. crassa. A number of different fluorescent dyes and fluorescent protein reporters were used to assess the effects of DAPG treatment on mitochondrial and other cellular functions. DAPG treatment led to changes in mitochondrial morphology, and rapid loss of mitochondrial membrane potential. These effects are likely to be responsible for the toxicity of DAPG. It was also found that DAPG treatment caused extracellular calcium to be taken up by conidial germlings leading to a transient increase in cytosolic free Ca(2+) with a distinct concentration dependent Ca(2+) signature.
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15
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Kubitschek-Barreira PH, Curty N, Neves GWP, Gil C, Lopes-Bezerra LM. Differential proteomic analysis of Aspergillus fumigatus morphotypes reveals putative drug targets. J Proteomics 2012; 78:522-34. [PMID: 23128298 DOI: 10.1016/j.jprot.2012.10.022] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Revised: 10/01/2012] [Accepted: 10/25/2012] [Indexed: 10/27/2022]
Abstract
Aspergillus fumigatus is the main etiological agent of invasive aspergillosis, an important opportunistic infection for neutropenic patients. The main risk groups are patients with acute leukemia and bone marrow transplantation recipients. The lack of an early diagnostic test together with the limited spectrum of antifungal drugs remains a setback to the successful treatment of this disease. During invasive infection the inhaled fungal conidia enter the morphogenic cycle leading to angioinvasive hyphae. This work aimed to study differentially expressed proteins of A. fumigatus during morphogenesis. To achieve this goal, a 2D-DIGE approach was applied to study surface proteins extractable by reducing agents of two A. fumigatus morphotypes: germlings and hyphae. Sixty-three differentially expressed proteins were identified by MALDI-ToF/MS. We observed that proteins associated with biosynthetic pathways and proteins with multiple functions (miscellaneous) were over-expressed in the early stages of germination, while in hyphae, the most abundant proteins detected were related to metabolic processes or have unknown functions. Among the most interesting proteins regulated during morphogenesis, two putative drug targets were identified, the translational factor, eEF3 and the CipC-like protein. Neither of these proteins are present in mammalian cells.
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Affiliation(s)
- Paula H Kubitschek-Barreira
- Laboratório de Micologia Celular e Proteômica, Instituto de Biologia, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil
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Bagar T, Benčina M. Antiarrhythmic drug amiodarone displays antifungal activity, induces irregular calcium response and intracellular acidification of Aspergillus niger - amiodarone targets calcium and pH homeostasis of A. niger. Fungal Genet Biol 2012; 49:779-91. [PMID: 22906851 DOI: 10.1016/j.fgb.2012.07.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Revised: 06/18/2012] [Accepted: 07/23/2012] [Indexed: 10/28/2022]
Abstract
The rapidly developing resistance of fungi to antifungal drugs is a serious health problem. Today's drugs mainly target cell membrane composition and synthesis. Moreover, some of them have serious side effects. New antifungal drugs targeting different molecular pathways are necessary. Amiodarone, an FDA approved antiarrhythmic drug displays antifungal activity. It targets calcium and pH homeostasis. In concentrations above 25 μM, it inhibits the growth of the filamentous fungi Aspergillus niger. It triggers a biphasic calcium response accompanied by a high [Ca(2+)](c) resting level and an intracellular acidification from 7.5 to 6.0, both of which are concentration dependent. Both extracellular calcium and calcium from intracellular organelles are sources of the transient second cytosolic calcium peak, whose amplitude is 0.12 μM for cells treated with 0.1mM amiodarone. In P-type ATPase deficient A. niger strains pmrAΔ and pmcAΔ, the [Ca(2+)](c) resting level after amiodarone treatment is at least twice as high as that of the wild type, which correlates with fungal viability and hypersensitivity to amiodarone. A combination of amiodarone and amphotericin B is additive in terms of cell viability and cytosolic calcium influx. In contrast, a combination of azole drugs and amiodarone has a synergistic effect on the viability of fungi.
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Affiliation(s)
- Tanja Bagar
- Department of Biotechnology, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia
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17
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Gutiérrez-Correa M, Ludeña Y, Ramage G, Villena GK. Recent Advances on Filamentous Fungal Biofilms for Industrial Uses. Appl Biochem Biotechnol 2012; 167:1235-53. [DOI: 10.1007/s12010-012-9555-5] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Accepted: 01/06/2012] [Indexed: 11/28/2022]
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18
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Binder U, Bencina M, Eigentler A, Meyer V, Marx F. The Aspergillus giganteus antifungal protein AFPNN5353 activates the cell wall integrity pathway and perturbs calcium homeostasis. BMC Microbiol 2011; 11:209. [PMID: 21943024 PMCID: PMC3197501 DOI: 10.1186/1471-2180-11-209] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Accepted: 09/23/2011] [Indexed: 01/25/2023] Open
Abstract
Background The antifungal protein AFPNN5353 is a defensin-like protein of Aspergillus giganteus. It belongs to a group of secretory proteins with low molecular mass, cationic character and a high content of cysteine residues. The protein inhibits the germination and growth of filamentous ascomycetes, including important human and plant pathogens and the model organsims Aspergillus nidulans and Aspergillus niger. Results We determined an AFPNN5353 hypersensitive phenotype of non-functional A. nidulans mutants in the protein kinase C (Pkc)/mitogen-activated protein kinase (Mpk) signalling pathway and the induction of the α-glucan synthase A (agsA) promoter in a transgenic A. niger strain which point at the activation of the cell wall integrity pathway (CWIP) and the remodelling of the cell wall in response to AFPNN5353. The activation of the CWIP by AFPNN5353, however, operates independently from RhoA which is the central regulator of CWIP signal transduction in fungi. Furthermore, we provide evidence that calcium (Ca2+) signalling plays an important role in the mechanistic function of this antifungal protein. AFPNN5353 increased about 2-fold the cytosolic free Ca2+ ([Ca2+]c) of a transgenic A. niger strain expressing codon optimized aequorin. Supplementation of the growth medium with CaCl2 counteracted AFPNN5353 toxicity, ameliorated the perturbation of the [Ca2+]c resting level and prevented protein uptake into Aspergillus sp. cells. Conclusions The present study contributes new insights into the molecular mechanisms of action of the A. giganteus antifungal protein AFPNN5353. We identified its antifungal activity, initiated the investigation of pathways that determine protein toxicity, namely the CWIP and the Ca2+ signalling cascade, and studied in detail the cellular uptake mechanism in sensitive target fungi. This knowledge contributes to define new potential targets for the development of novel antifungal strategies to prevent and combat infections of filamentous fungi which have severe negative impact in medicine and agriculture.
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Affiliation(s)
- Ulrike Binder
- Biocenter, Division of Molecular Biology, Innsbruck Medical University, Fritz-Pregl Strasse 3, Innsbruck, A-6020, Austria
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Ramage G, Rajendran R, Gutierrez-Correa M, Jones B, Williams C. Aspergillus biofilms: clinical and industrial significance. FEMS Microbiol Lett 2011; 324:89-97. [PMID: 22092808 DOI: 10.1111/j.1574-6968.2011.02381.x] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Revised: 08/09/2011] [Accepted: 08/09/2011] [Indexed: 11/30/2022] Open
Abstract
The biofilm phenotype is an increasingly important concept in mycological research. Recently, there has been a developing interest in whether Aspergillus species are truly able to form biofilms or not. Industrial mycologists have long been aware of biofilms and their benefit in fermentation processes, whereas clinically their role is uncertain. This review provides an update on the impact that Aspergillus biofilms have medically and industrially, and will discuss biofilm development, and our current understanding of its molecular basis. The role of exopolymeric substance and how this substance relates to antimicrobial recalcitrance will also be discussed.
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Affiliation(s)
- Gordon Ramage
- School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, UK.
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20
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Tamiji J, Crawford DA. Misoprostol elevates intracellular calcium in Neuro-2a cells via protein kinase A. Biochem Biophys Res Commun 2010; 399:565-70. [PMID: 20678471 DOI: 10.1016/j.bbrc.2010.07.112] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Accepted: 07/27/2010] [Indexed: 11/15/2022]
Abstract
Misoprostol, a prostaglandin type E analogue, has been implicated in a number of neurodevelopmental disorders. However, its mode of action in the nervous system is not well understood. Misoprostol acts on the same receptors as prostaglandin E(2) (PGE(2)), a natural lipid-derived compound, which mediates important physiological functions in the nervous system via activation of four EP receptors (EP1-4). In this study we use a ratiometric calcium imaging with fura-2 AM as a calcium indicator to show that misoprostol alters intracellular calcium levels in mouse neuroblastoma (Neuro-2a) cells via similar mechanisms as PGE(2). We demonstrate that the misoprostol-induced increase in calcium is mediated by a protein kinase A (PKA)-dependent mechanism and that the EP4 receptor signaling pathway may play an inhibitory role on calcium regulation. Overall, this study provides further support for the involvement of PGE(2) signaling in calcium homeostasis and suggests its important role in the nervous system.
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Affiliation(s)
- Javaneh Tamiji
- School of Kinesiology and Health Science, York University, Toronto, Canada; Neuroscience Graduate Diploma Program, York University, Toronto, Canada
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21
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The antifungal activity of the Penicillium chrysogenum protein PAF disrupts calcium homeostasis in Neurospora crassa. EUKARYOTIC CELL 2010; 9:1374-82. [PMID: 20622001 DOI: 10.1128/ec.00050-10] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The antifungal protein PAF from Penicillium chrysogenum exhibits growth-inhibitory activity against a broad range of filamentous fungi. Evidence from this study suggests that disruption of Ca(2+) signaling/homeostasis plays an important role in the mechanistic basis of PAF as a growth inhibitor. Supplementation of the growth medium with high Ca(2+) concentrations counteracted PAF toxicity toward PAF-sensitive molds. By using a transgenic Neurospora crassa strain expressing codon-optimized aequorin, PAF was found to cause a significant increase in the resting level of cytosolic free Ca(2+) ([Ca(2+)](c)). The Ca(2+) signatures in response to stimulation by mechanical perturbation or hypo-osmotic shock were significantly changed in the presence of PAF. BAPTA [bis-(aminophenoxy)-ethane-N,N,N',N'-tetraacetic acid], a Ca(2+) selective chelator, ameliorated the PAF toxicity in growth inhibition assays and counteracted PAF induced perturbation of Ca(2+) homeostasis. These results indicate that extracellular Ca(2+) was the major source of these PAF-induced effects. The L-type Ca(2+) channel blocker diltiazem disrupted Ca(2+) homeostasis in a similar manner to PAF. Diltiazem in combination with PAF acted additively in enhancing growth inhibition and accentuating the change in Ca(2+) signatures in response to external stimuli. Notably, both PAF and diltiazem increased the [Ca(2+)](c) resting level. However, experiments with an aequorin-expressing Deltacch-1 deletion strain of N. crassa indicated that the L-type Ca(2+) channel CCH-1 was not responsible for the observed PAF-induced elevation of the [Ca(2+)](c) resting level. This study is the first demonstration of the perturbation of fungal Ca(2+) homeostasis by an antifungal protein from a filamentous ascomycete and provides important new insights into the mode of action of PAF.
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22
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Webb SE, Rogers KL, Karplus E, Miller AL. The use of aequorins to record and visualize Ca(2+) dynamics: from subcellular microdomains to whole organisms. Methods Cell Biol 2010; 99:263-300. [PMID: 21035690 DOI: 10.1016/b978-0-12-374841-6.00010-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
In this chapter, we describe the practical aspects of measuring [Ca(2+)] transients that are generated in a particular cytoplasmic domain, or within a specific organelle or its periorganellar environment, using bioluminescent, genetically encoded and targeted Ca(2+) reporters, especially those based on apoaequorin. We also list examples of the organisms, tissues, and cells that have been transfected with apoaequorin or an apoaequorin-BRET complex, as well as of the organelles and subcellular domains that have been specifically targeted with these bioluminescent Ca(2+) reporters. In addition, we summarize the various techniques used to load the apoaequorin cofactor, coelenterazine, and its analogs into cells, tissues, and intact organisms, and we describe recent advances in the detection and imaging technologies that are currently being used to measure and visualize the luminescence generated by the aequorin-Ca(2+) reaction within these various cytoplasmic domains and subcellular compartments.
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Affiliation(s)
- Sarah E Webb
- Biochemistry and Cell Biology Section and State Key Laboratory of Molecular Neuroscience, Division of Life Science, HKUST, Clear Water Bay, Kowloon, Hong Kong, PR China
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23
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Binder U, Oberparleiter C, Meyer V, Marx F. The antifungal protein PAF interferes with PKC/MPK and cAMP/PKA signalling of Aspergillus nidulans. Mol Microbiol 2009; 75:294-307. [PMID: 19889092 PMCID: PMC2814085 DOI: 10.1111/j.1365-2958.2009.06936.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The Penicillium chrysogenum antifungal protein PAF inhibits polar growth and induces apoptosis in Aspergillus nidulans. We report here that two signalling cascades are implicated in its antifungal activity. PAF activates the cAMP/protein kinase A (Pka) signalling cascade. A pkaA deletion mutant exhibited reduced sensitivity towards PAF. This was substantiated by the use of pharmacological modulators: PAF aggravated the effect of the activator 8-Br-cAMP and partially relieved the repressive activity of caffeine. Furthermore, the Pkc/mitogen-activated protein kinase (Mpk) signalling cascade mediated basal resistance to PAF, which was independent of the small GTPase RhoA. Non-functional mutations of both genes resulted in hypersensitivity towards PAF. PAF did not increase MpkA phosphorylation or induce enzymes involved in the remodelling of the cell wall, which normally occurs in response to activators of the cell wall integrity pathway. Notably, PAF exposure resulted in actin gene repression and a deregulation of the chitin deposition at hyphal tips of A. nidulans, which offers an explanation for the morphological effects evoked by PAF and which could be attributed to the interconnection of the two signalling pathways. Thus, PAF represents an excellent tool to study signalling pathways in this model organism and to define potential fungal targets to develop new antifungals.
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Affiliation(s)
- Ulrike Binder
- Biocenter, Division of Molecular Biology, Innsbruck Medical University, Innsbruck, Austria
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24
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Reconstruction of signaling networks regulating fungal morphogenesis by transcriptomics. EUKARYOTIC CELL 2009; 8:1677-91. [PMID: 19749177 DOI: 10.1128/ec.00050-09] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Coordinated control of hyphal elongation and branching is essential for sustaining mycelial growth of filamentous fungi. In order to study the molecular machinery ensuring polarity control in the industrial fungus Aspergillus niger, we took advantage of the temperature-sensitive (ts) apical-branching ramosa-1 mutant. We show here that this strain serves as an excellent model system to study critical steps of polar growth control during mycelial development and report for the first time a transcriptomic fingerprint of apical branching for a filamentous fungus. This fingerprint indicates that several signal transduction pathways, including TORC2, phospholipid, calcium, and cell wall integrity signaling, concertedly act to control apical branching. We furthermore identified the genetic locus affected in the ramosa-1 mutant by complementation of the ts phenotype. Sequence analyses demonstrated that a single amino acid exchange in the RmsA protein is responsible for induced apical branching of the ramosa-1 mutant. Deletion experiments showed that the corresponding rmsA gene is essential for the growth of A. niger, and complementation analyses with Saccharomyces cerevisiae evidenced that RmsA serves as a functional equivalent of the TORC2 component Avo1p. TORC2 signaling is required for actin polarization and cell wall integrity in S. cerevisiae. Congruently, our microscopic investigations showed that polarized actin organization and chitin deposition are disturbed in the ramosa-1 mutant. The integration of the transcriptomic, genetic, and phenotypic data obtained in this study allowed us to reconstruct a model for cellular events involved in apical branching.
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Elongation factor 3, EF3, associates with the calcium channel Cch1 and targets Cch1 to the plasma membrane in Cryptococcus neoformans. EUKARYOTIC CELL 2008; 7:1118-26. [PMID: 18503003 DOI: 10.1128/ec.00116-08] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Ca2+-mediated signaling events in eukaryotic cells are initiated by Ca2+ channels located in the plasma membranes and endomembranes. Cch1, a high-affinity Ca2+ channel in the plasma membranes of Cryptococcus neoformans and other fungi, plays a role in many different cellular processes, but the mechanisms that regulate Cch1 are not well understood. A Ras recruitment two-hybrid screen was used to identify protein partners of Cch1 as a means of identifying possible mechanisms of channel regulation. Here, we show that Cch1 specifically associates with a cytoplasmic protein known as elongation factor 3 (EF3). The robust interaction between the cytosolic C terminus of the Cch1 protein and EF3 shown here was confirmed by demonstrating that Cch1 could coimmunoprecipitate with EF3 in yeast lysates. To examine the effects of EF3 on Cch1 behavior, we altered the EF3 gene function by constructing a C. neoformans antisense EF3 repression strain. Our results show that the repression of EF3 led to the mislocalization of Cch1, suggesting a role for EF3 in targeting Cch1 to the plasma membrane of C. neoformans. Consistent with this notion, the antisense EF3 repression strain displayed a growth defect under conditions of limited extracellular Ca2+. Collectively, these results suggest that EF3 and Cch1 are functionally coupled and that EF3 has a function apart from its role in the protein translation cycle.
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26
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Nguyen QB, Kadotani N, Kasahara S, Tosa Y, Mayama S, Nakayashiki H. Systematic functional analysis of calcium-signalling proteins in the genome of the rice-blast fungus, Magnaporthe oryzae, using a high-throughput RNA-silencing system. Mol Microbiol 2008; 68:1348-65. [PMID: 18433453 DOI: 10.1111/j.1365-2958.2008.06242.x] [Citation(s) in RCA: 153] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We developed an RNA-silencing vector, pSilent-Dual1 (pSD1), with a convergent dual promoter system that provides a high-throughput platform for functional genomics research in filamentous fungi. In the pSD1 system, the target gene was designed to be transcribed as a chimeric RNA with enhanced green fluorescent protein (eGFP) RNA. This enabled us to efficiently screen the resulting transformants using GFP fluorescence as an indicator of gene silencing. A model study with the eGFP gene showed that pSD1-based vectors induced gene silencing via the RNAi pathway with slightly lower efficiency than did hairpin eGFP RNA-expressing vectors. To demonstrate the applicability of the pSD1 system for elucidating gene function in the rice-blast fungus Magnaporthe oryzae, 37 calcium signalling-related genes that include almost all known calcium-signalling proteins in the genome were targeted for gene silencing by the vector. Phenotypic analyses of the silenced transformants showed that at least 26, 35 and 15 of the 37 genes examined were involved in hyphal growth, sporulation and pathogenicity, respectively, in M. oryzae. These included several novel findings such as that Pmc1-, Spf1- and Neo1-like Ca(2+) pumps, calreticulin and calpactin heavy chain were essential for fungal pathogenicity.
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Affiliation(s)
- Quoc Bao Nguyen
- Laboratory of Plant Pathology, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodaicho, Nada, Kobe, Japan
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Schumacher J, Viaud M, Simon A, Tudzynski B. The Gα subunit BCG1, the phospholipase C (BcPLC1) and the calcineurin phosphatase co-ordinately regulate gene expression in the grey mould fungus Botrytis cinerea. Mol Microbiol 2008; 67:1027-50. [DOI: 10.1111/j.1365-2958.2008.06105.x] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Bouts DMD, Melo ACDA, Andrade ALH, Silva-Neto MAC, Paiva-Silva GDO, Sorgine MHF, da Cunha Gomes LS, Coelho HS, Furtado AP, Aguiar ECM, de Medeiros LN, Kurtenbach E, Rozental S, Cunha-E-Silva NL, de Souza W, Masuda H. Biochemical properties of the major proteins from Rhodnius prolixus eggshell. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2007; 37:1207-1221. [PMID: 17916507 DOI: 10.1016/j.ibmb.2007.07.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2007] [Accepted: 07/17/2007] [Indexed: 05/25/2023]
Abstract
Two proteins from the eggshell of Rhodnius prolixus were isolated, characterized and named Rp30 and Rp45 according to their molecular masses. Purified proteins were used to obtain specific antiserum which was later used for immunolocalization. The antiserum against Rp30 and Rp45 detected their presence inside the follicle cells, their secretion and their association with oocyte microvilli. Both proteins are expressed during the final stage of vitellogenesis, preserved during embryogenesis and discarded together with the eggshell. The amino terminals were sequenced and both proteins were further cloned using degenerated primers. The amino acid sequences appear to have a tripartite arrangement with a highly conserved central domain which presents a repetitive motif of valine-proline-valine (VPV) at intervals of 15 amino acid residues. Their amino acid sequence showed no similarity to any known eggshell protein. The expression of these proteins was also investigated; the results demonstrated that this occurred strictly in choriogenic follicles. Antifungal activity against Aspergillus niger was found to be associated with Rp45 but not with Rp30. A. niger exposed to Rp45 protein induced growth inhibition and several morphological changes such as large vacuoles, swollen mitochondria, multi-lamellar structures and a disorganized cell wall as demonstrated by electron microscopy analysis.
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Affiliation(s)
- Denise M D Bouts
- Instituto de Bioquímica Médica, Programa de Biologia Molecular e Biotecnologia, Universidade Federal do Rio de Janeiro, 21941-902 Rio de Janeiro/RJ, Brazil
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Wright GD, Arlt J, Poon WCK, Read ND. Optical tweezer micromanipulation of filamentous fungi. Fungal Genet Biol 2006; 44:1-13. [PMID: 16908207 DOI: 10.1016/j.fgb.2006.07.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2006] [Revised: 07/03/2006] [Accepted: 07/05/2006] [Indexed: 11/21/2022]
Abstract
Optical tweezers have been little used in experimental studies on filamentous fungi. We have built a simple, compact, easy-to-use, safe and robust optical tweezer system that can be used with brightfield, phase contrast, differential interference contrast and fluorescence optics on a standard research grade light microscope. We have used this optical tweezer system in a range of cell biology applications to trap and micromanipulate whole fungal cells, organelles within cells, and beads. We have demonstrated how optical tweezers can be used to: unambiguously determine whether hyphae are actively homing towards each other; move the Spitzenkörper and change the pattern of hyphal morphogenesis; make piconewton force measurements; mechanically stimulate hyphal tips; and deliver chemicals to localized regions of hyphae. Significant novel experimental findings from our study were that germ tubes generated significantly smaller growth forces than leading hyphae, and that both hyphal types exhibited growth responses to mechanical stimulation with optically trapped polystyrene beads. Germinated spores that had been optically trapped for 25min exhibited no deleterious effects with regard to conidial anastomosis tube growth, homing or fusion.
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Affiliation(s)
- Graham D Wright
- Fungal Cell Biology Group, Institute of Cell Biology, University of Edinburgh, Rutherford Building, Edinburgh, UK
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