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Dai M, Liu X, Goldman GH, Lu L, Zhang S. The EH domain-containing protein, EdeA, is involved in endocytosis, cell wall integrity, and pathogenicity in Aspergillus fumigatus. mSphere 2024; 9:e0005724. [PMID: 38687129 PMCID: PMC11237632 DOI: 10.1128/msphere.00057-24] [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: 01/29/2024] [Accepted: 03/29/2024] [Indexed: 05/02/2024] Open
Abstract
Endocytosis has been extensively studied in yeasts, where it plays crucial roles in growth, signaling regulation, and cell-surface receptor internalization. However, the biological functions of endocytosis in pathogenic filamentous fungi remain largely unexplored. In this study, we aimed to functionally characterize the roles of EdeA, an ortholog of the Saccharomyces cerevisiae endocytic protein Ede1, in Aspergillus fumigatus. EdeA was observed to be distributed as patches on the plasma membrane and concentrated in the subapical collar of hyphae, a localization characteristic of endocytic proteins. Loss of edeA caused defective hyphal polarity, reduced conidial production, and fewer sites of endocytosis initiations than that of the parental wild type. Notably, the edeA null mutant exhibited increased sensitivity to cell wall-disrupting agents, indicating a role for EdeA in maintaining cell wall integrity in A. fumigatus. This observation was further supported by the evidence showing that the thickness of the cell wall in the ΔedeA mutant increased, accompanied by abnormal activation of MpkA, a key component in the cell wall integrity pathway. Additionally, the ΔedeA mutant displayed increased pathogenicity in the Galleria mellonella wax moth infection model, possibly due to alterations in cell wall morphology. Site-directed mutagenesis identified the conserved residue E348 within the third EH (Eps15 homology) domain of EdeA as crucial for its subcellular localization and functions. In conclusion, our results highlight the involvement of EdeA in endocytosis, hyphal polarity, cell wall integrity, and pathogenicity in A. fumigatus. IMPORTANCE Aspergillus fumigatus is a significant human pathogenic fungus known to cause invasive aspergillosis, a disease with a high mortality rate. Understanding the basic principles of A. fumigatus pathogenicity is crucial for developing effective strategies against this pathogen. Previous research has underscored the importance of endocytosis in the infection capacity of pathogenic yeasts; however, its biological function in pathogenic mold remains largely unexplored. Our characterization of EdeA in A. fumigatus sheds light on the role of endocytosis in the development, stress response, and pathogenicity of pathogenic molds. These findings suggest that the components of the endocytosis process may serve as potential targets for antifungal therapy.
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Affiliation(s)
- Mengyao Dai
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Centre for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Xintian Liu
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Centre for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Gustavo H Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Ling Lu
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Centre for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Shizhu Zhang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Centre for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China
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2
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Qu S, Chi SD, He ZM. The Development of Aspergillus flavus and Biosynthesis of Aflatoxin B1 are Regulated by the Golgi-Localized Mn 2+ Transporter Pmr1. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:1276-1291. [PMID: 38179648 DOI: 10.1021/acs.jafc.3c06964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2024]
Abstract
Microorganisms rely on diverse ion transport and trace elements to sustain growth, development, and secondary metabolism. Manganese (Mn2+) is essential for various biological processes and plays a crucial role in the metabolism of human cells, plants, and yeast. In Aspergillus flavus, we confirmed that Pmr1 localized in cis- and medial-Golgi compartments was critical in facilitating Mn2+ transport, fungal growth, development, secondary metabolism, and glycosylation. In comparison to the wild type, the Δpmr1 mutant displayed heightened sensitivity to environmental stress, accompanied by inhibited synthesis of aflatoxin B1, kojic acid, and a substantial reduction in pathogenicity toward peanuts and maize. Interestingly, the addition of exogenous Mn2+ effectively rectified the developmental and secondary metabolic defects in the Δpmr1 mutant. However, Mn2+ supplement failed to restore the growth and development of the Δpmr1Δgdt1 double mutant, which indicated that the Gdt1 compensated for the functional deficiency of pmr1. In addition, our results showed that pmr1 knockout leads to an upregulation of O-glycosyl-N-acetylglucose (O-GlcNAc) and O-GlcNAc transferase (OGT), while Mn2+ supplementation can restore the glycosylation in A. flavus. Collectively, this study indicates that the pmr1 regulates Mn2+ via Golgi and maintains growth and metabolism functions of A. flavus through regulation of the glycosylation.
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Affiliation(s)
- Su Qu
- School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Sheng-Da Chi
- School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Zhu-Mei He
- School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China
- School of Medicine, Sun Yat-sen University, Shenzhen 518107, China
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3
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Hill TW, Vance S, Loome JF, Haugen BJ, Loprete DM, Stoddard SV, Jackson-Hayes L. A member of the OSCA/TMEM63 family of mechanosensitive calcium channels participates in cell wall integrity maintenance in Aspergillus nidulans. Fungal Genet Biol 2023; 169:103842. [PMID: 37805121 DOI: 10.1016/j.fgb.2023.103842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Revised: 10/01/2023] [Accepted: 10/05/2023] [Indexed: 10/09/2023]
Abstract
The calF7 mutation in Aspergillus nidulans causes hypersensitivity to the cell wall compromising agents Calcofluor White (CFW) and Congo Red. In this research we demonstrate that the calF7 mutation resides in gene AN2880, encoding a predicted member of the OSCA/TMEM63 family of transmembrane glycoproteins. Those members of the family whose physiological functions have been investigated have been shown to act as mechanosensitive calcium transport channels. Deletion of AN2880 replicates the CFW hypersensitivity phenotype. Separately, we show that CFW hypersensitivity of calF deletion strains can be overcome by inclusion of elevated levels of extracellular calcium ions in the growth medium, and, correspondingly, wild type strains grown in media deficient in calcium ions are no longer resistant to CFW. These observations support a model in which accommodation to at least some forms of cell wall stress is mediated by a calcium ion signaling system in which the AN2880 gene product plays a role. The genetic lesion in calF7 is predicted to result in a glycine-to-arginine substitution at position 638 of the 945-residue CalF protein in a region of the RSN1_7TM domain that is highly conserved amongst filamentous fungi. Homology modeling predicts that the consequence of a G638R substitution is to structurally occlude the principal conductance pore in the protein. GFP-tagged wild type CalF localizes principally to the Spitzenkörper and the plasma membrane at growing tips and forming septa. However, both septation and hyphal morphology appear to be normal in calF7 and AN2880 deletion strains, indicating that any role played by CalF in normal hyphal growth and cytokinesis is dispensable.
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Affiliation(s)
- Terry W Hill
- Department of Biology, Rhodes College, Memphis, TN 38112, USA; Biochemistry and Molecular Biology Program, Rhodes College, Memphis, TN 38112, USA.
| | - Stanley Vance
- Department of Chemistry, Rhodes College, Memphis, TN 38112, USA
| | - Jennifer F Loome
- Biochemistry and Molecular Biology Program, Rhodes College, Memphis, TN 38112, USA
| | - Benard J Haugen
- Biochemistry and Molecular Biology Program, Rhodes College, Memphis, TN 38112, USA
| | - Darlene M Loprete
- Biochemistry and Molecular Biology Program, Rhodes College, Memphis, TN 38112, USA; Department of Chemistry, Rhodes College, Memphis, TN 38112, USA
| | - Shana V Stoddard
- Biochemistry and Molecular Biology Program, Rhodes College, Memphis, TN 38112, USA; Department of Chemistry, Rhodes College, Memphis, TN 38112, USA
| | - Loretta Jackson-Hayes
- Biochemistry and Molecular Biology Program, Rhodes College, Memphis, TN 38112, USA; Department of Chemistry, Rhodes College, Memphis, TN 38112, USA
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Zhao X, Fan Y, Zhang L, Zhang W, Xiang M, Kang S, Wang S, Liu X. Multiple Roles of the Low-Affinity Calcium Uptake System in Drechslerella dactyloides, a Nematode-Trapping Fungus That Forms Constricting Rings. J Fungi (Basel) 2023; 9:975. [PMID: 37888231 PMCID: PMC10607529 DOI: 10.3390/jof9100975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 09/26/2023] [Accepted: 09/27/2023] [Indexed: 10/28/2023] Open
Abstract
(1) Background: the low-affinity calcium uptake system (LACS) has been shown to play a crucial role in the conidiation and formation of adhesive nets and knobs by nematode-trapping fungi (NTF), but its involvement in the formation of constricting rings (CRs), mechanical traps to capture free-living nematodes, remains unexplored. (2) Methods: we investigated the function of two LACS genes (DdaFIG_1 and DdaFIG_2) in Drechslerella dactyloides, an NTF that forms CRs. We generated single (DdaFIG_1Ri and DdaFIG_2Ri) and double (DdaFIG_1,2Ri) knockdown mutants via the use of RNA interference (RNAi). (3) Results: suppression of these genes significantly affected conidiation, trap formation, vegetative growth, and response to diverse abiotic stresses. The number of CRs formed by DdaFIG_1Ri, DdaFIG_2Ri, and DdaFIG_1,2Ri decreased to 58.5%, 59.1%, and 38.9% of the wild-type (WT) level, respectively. The ring cell inflation rate also decreased to 73.6%, 60.6%, and 48.8% of the WT level, respectively. (4) Conclusions: the LACS plays multiple critical roles in diverse NTF.
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Affiliation(s)
- Xiaozhou Zhao
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Science, Nankai University, Tianjin 300071, China
| | - Yani Fan
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Liao Zhang
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Science, Nankai University, Tianjin 300071, China
| | - Weiwei Zhang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Meichun Xiang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Seogchan Kang
- Department of Plant Pathology & Environmental Microbiology, The Pennsylvania State University, University Park, PA 16802, USA;
| | - Shunxian Wang
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Science, Nankai University, Tianjin 300071, China
| | - Xingzhong Liu
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Science, Nankai University, Tianjin 300071, China
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Son YE, Yu JH, Park HS. Regulators of the Asexual Life Cycle of Aspergillus nidulans. Cells 2023; 12:1544. [PMID: 37296664 PMCID: PMC10253035 DOI: 10.3390/cells12111544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 06/01/2023] [Accepted: 06/02/2023] [Indexed: 06/12/2023] Open
Abstract
The genus Aspergillus, one of the most abundant airborne fungi, is classified into hundreds of species that affect humans, animals, and plants. Among these, Aspergillus nidulans, as a key model organism, has been extensively studied to understand the mechanisms governing growth and development, physiology, and gene regulation in fungi. A. nidulans primarily reproduces by forming millions of asexual spores known as conidia. The asexual life cycle of A. nidulans can be simply divided into growth and asexual development (conidiation). After a certain period of vegetative growth, some vegetative cells (hyphae) develop into specialized asexual structures called conidiophores. Each A. nidulans conidiophore is composed of a foot cell, stalk, vesicle, metulae, phialides, and 12,000 conidia. This vegetative-to-developmental transition requires the activity of various regulators including FLB proteins, BrlA, and AbaA. Asymmetric repetitive mitotic cell division of phialides results in the formation of immature conidia. Subsequent conidial maturation requires multiple regulators such as WetA, VosA, and VelB. Matured conidia maintain cellular integrity and long-term viability against various stresses and desiccation. Under appropriate conditions, the resting conidia germinate and form new colonies, and this process is governed by a myriad of regulators, such as CreA and SocA. To date, a plethora of regulators for each asexual developmental stage have been identified and investigated. This review summarizes our current understanding of the regulators of conidial formation, maturation, dormancy, and germination in A. nidulans.
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Affiliation(s)
- Ye-Eun Son
- Major in Food Biomaterials, School of Food Science and Biotechnology, Kyungpook National University, Daegu 41566, Republic of Korea;
| | - Jae-Hyuk Yu
- Department of Bacteriology, Food Research Institute, University of Wisconsin-Madison, Madison, WI 53706, USA;
| | - Hee-Soo Park
- Major in Food Biomaterials, School of Food Science and Biotechnology, Kyungpook National University, Daegu 41566, Republic of Korea;
- Department of Integrative Biology, Kyungpook National University, Daegu 41566, Republic of Korea
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Zuo H, Ji L, Pan J, Chen X, Gao C, Liu J, Wei W, Wu J, Song W, Liu L. Engineering growth phenotypes of Aspergillus oryzae for L-malate production. BIORESOUR BIOPROCESS 2023; 10:25. [PMID: 38647943 PMCID: PMC10991988 DOI: 10.1186/s40643-023-00642-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Accepted: 03/09/2023] [Indexed: 04/09/2023] Open
Abstract
Improving the growth status of Aspergillus oryzae is an efficient way to enhance L-malate production. However, the growth mechanism of filamentous fungi is relatively complex, which limits A. oryzae as a cell factory to produce L-malate industrially. This study determined the relationship between growth status and L-malate production. The optimal ranges of colony diameter, percentage of vegetative mycelia, and pellet number of A. oryzae were determined to be 26-30 mm, 35-40%, and 220-240/mL, respectively. To achieve this optimum range, adaptive evolution was used to obtain the evolved strain Z07 with 132.54 g/L L-malate and a productivity of 1.1 g/L/h. Finally, a combination of transcriptome analysis and morphological characterization was used to identify the relevant pathway genes that affect the growth mechanism of A. oryzae. The strategies used in this study and the growth mechanism provide a good basis for efficient L-malate production by filamentous fungi.
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Affiliation(s)
- Huiyun Zuo
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Lihao Ji
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Jingyu Pan
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Xiulai Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Cong Gao
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Jia Liu
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Wanqing Wei
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Jing Wu
- School of Pharmaceutical Science, Jiangnan University, Wuxi, 214122, Jiangsu, China
| | - Wei Song
- School of Pharmaceutical Science, Jiangnan University, Wuxi, 214122, Jiangsu, China
| | - Liming Liu
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China.
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China.
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7
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Cell wall dynamics stabilize tip growth in a filamentous fungus. PLoS Biol 2023; 21:e3001981. [PMID: 36649360 PMCID: PMC9882835 DOI: 10.1371/journal.pbio.3001981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 01/27/2023] [Accepted: 12/22/2022] [Indexed: 01/18/2023] Open
Abstract
Hyphal tip growth allows filamentous fungi to colonize space, reproduce, or infect. It features remarkable morphogenetic plasticity including unusually fast elongation rates, tip turning, branching, or bulging. These shape changes are all driven from the expansion of a protective cell wall (CW) secreted from apical pools of exocytic vesicles. How CW secretion, remodeling, and deformation are modulated in concert to support rapid tip growth and morphogenesis while ensuring surface integrity remains poorly understood. We implemented subresolution imaging to map the dynamics of CW thickness and secretory vesicles in Aspergillus nidulans. We found that tip growth is associated with balanced rates of CW secretion and expansion, which limit temporal fluctuations in CW thickness, elongation speed, and vesicle amount, to less than 10% to 20%. Affecting this balance through modulations of growth or trafficking yield to near-immediate changes in CW thickness, mechanics, and shape. We developed a model with mechanical feedback that accounts for steady states of hyphal growth as well as rapid adaptation of CW mechanics and vesicle recruitment to different perturbations. These data provide unprecedented details on how CW dynamics emerges from material secretion and expansion, to stabilize fungal tip growth as well as promote its morphogenetic plasticity.
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8
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He C, Wei Q, Xu J, Cai R, Kong Q, Chen P, Lu L, Sang H. bHLH transcription factor EcdR controls conidia production, pigmentation and virulence in Aspergillus fumigatus. Fungal Genet Biol 2023; 164:103751. [PMID: 36375736 DOI: 10.1016/j.fgb.2022.103751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 11/04/2022] [Accepted: 11/07/2022] [Indexed: 11/13/2022]
Abstract
Invasive Aspergillus fumigatus infection is a disease with high morbidity and mortality rates. Abnormalities in sporulation and pigmentation can significantly alter the pathogenicity of A. fumigatus, thus the mechanisms of conidiation and pigment biosynthesis have gained increasing attention. In Aspergillus oryzae, a novel predicted bHLH protein-encoding gene, ecdR, plays a role in asexual development, and its ortholog has also been characterized in A. nidulans. Herein, we determined its role in A. fumigatus by testing whether ecdR deletion affects asexual development, melanin synthesis, and regulation of virulence in this fungus. Our study shows that EcdR controls conidia and melanin production in A. fumigatus. In addition, we found that virulence in the ΔecdR strain was significantly reduced in the infection model of immunodeficiency mice.
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Affiliation(s)
- Cong He
- Affiliated Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Qian Wei
- Affiliated Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Jie Xu
- Affiliated Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Renhui Cai
- Department of Dermatology, Jinling Hospital, Southern Medical University, Guangzhou, China
| | - Qingtao Kong
- Affiliated Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Peiying Chen
- Affiliated Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Ling Lu
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Hong Sang
- Affiliated Jinling Hospital, Medical School of Nanjing University, Nanjing, China; Department of Dermatology, Jinling Hospital, Southern Medical University, Guangzhou, China.
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9
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Ancuceanu R, Hovaneț MV, Cojocaru-Toma M, Anghel AI, Dinu M. Potential Antifungal Targets for Aspergillus sp. from the Calcineurin and Heat Shock Protein Pathways. Int J Mol Sci 2022; 23:ijms232012543. [PMID: 36293395 PMCID: PMC9603945 DOI: 10.3390/ijms232012543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 10/13/2022] [Accepted: 10/15/2022] [Indexed: 11/16/2022] Open
Abstract
Aspergillus species, especially A. fumigatus, and to a lesser extent others (A. flavus, A. niger, A. terreus), although rarely pathogenic to healthy humans, can be very aggressive to immunocompromised patients (they are opportunistic pathogens). Although survival rates for such infections have improved in recent decades following the introduction of azole derivatives, they remain a clinical challenge. The fact that current antifungals act as fungistatic rather than fungicide, that they have limited safety, and that resistance is becoming increasingly common make the need for new, more effective, and safer therapies to become more acute. Over the last decades, knowledge about the molecular biology of A. fumigatus and other Aspergillus species, and particularly of calcineurin, Hsp90, and their signaling pathway proteins, has progressed remarkably. Although calcineurin has attracted much interest, its adverse effects, particularly its immunosuppressive effects, make it less attractive than it might at first appear. The situation is not very different for Hsp90. Other proteins from their signaling pathways, such as protein kinases phosphorylating the four SPRR serine residues, CrzA, rcnA, pmcA-pmcC (particularly pmcC), rfeF, BAR adapter protein(s), the phkB histidine kinase, sskB MAP kinase kinase, zfpA, htfA, ctfA, SwoH (nucleoside diphosphate kinase), CchA, MidA, FKBP12, the K27 lysine position from Hsp90, PkcA, MpkA, RlmA, brlA, abaA, wetA, other heat shock proteins (Hsp70, Hsp40, Hsp12) currently appear promising and deserve further investigation as potential targets for antifungal drug development.
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Affiliation(s)
- Robert Ancuceanu
- Faculty of Pharmacy, Carol Davila University of Medicine and Pharmacy, 020956 Bucharest, Romania
- Correspondence: (R.A.); (M.V.H.)
| | - Marilena Viorica Hovaneț
- Faculty of Pharmacy, Carol Davila University of Medicine and Pharmacy, 020956 Bucharest, Romania
- Correspondence: (R.A.); (M.V.H.)
| | - Maria Cojocaru-Toma
- Faculty of Pharmacy, Nicolae Testemițanu State University of Medicine and Pharmacy, 2025 Chisinau, Moldova
| | - Adriana-Iuliana Anghel
- Faculty of Pharmacy, Carol Davila University of Medicine and Pharmacy, 020956 Bucharest, Romania
| | - Mihaela Dinu
- Faculty of Pharmacy, Carol Davila University of Medicine and Pharmacy, 020956 Bucharest, Romania
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10
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Yang Y, Xie P, Li Y, Bi Y, Prusky DB. Updating Insights into the Regulatory Mechanisms of Calcineurin-Activated Transcription Factor Crz1 in Pathogenic Fungi. J Fungi (Basel) 2022; 8:1082. [PMID: 36294647 PMCID: PMC9604740 DOI: 10.3390/jof8101082] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 10/06/2022] [Accepted: 10/10/2022] [Indexed: 11/05/2022] Open
Abstract
Ca2+, as a second messenger in cells, enables organisms to adapt to different environmental stresses by rapidly sensing and responding to external stimuli. In recent years, the Ca2+ mediated calcium signaling pathway has been studied systematically in various mammals and fungi, indicating that the pathway is conserved among organisms. The pathway consists mainly of complex Ca2+ channel proteins, calcium pumps, Ca2+ transporters and many related proteins. Crz1, a transcription factor downstream of the calcium signaling pathway, participates in regulating cell survival, ion homeostasis, infection structure development, cell wall integrity and virulence. This review briefly summarizes the Ca2+ mediated calcium signaling pathway and regulatory roles in plant pathogenic fungi. Based on discussing the structure and localization of transcription factor Crz1, we focus on the regulatory role of Crz1 on growth and development, stress response, pathogenicity of pathogenic fungi and its regulatory mechanisms. Furthermore, we explore the cross-talk between Crz1 and other signaling pathways. Combined with the important role and pathogenic mechanism of Crz1 in fungi, the new strategies in which Crz1 may be used as a target to explore disease control in practice are also discussed.
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Affiliation(s)
- Yangyang Yang
- College of Food Science and Engineering, Gansu Agricultural University, Lanzhou 730070, China
| | - Pengdong Xie
- College of Food Science and Engineering, Gansu Agricultural University, Lanzhou 730070, China
| | - Yongcai Li
- College of Food Science and Engineering, Gansu Agricultural University, Lanzhou 730070, China
| | - Yang Bi
- College of Food Science and Engineering, Gansu Agricultural University, Lanzhou 730070, China
| | - Dov B. Prusky
- Department of Postharvest Science, Agricultural Research Organization, Volcani Center, Rishon LeZion 7505101, Israel
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11
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Wang H, Chen Q, Zhang S, Lu L. A Transient Receptor Potential-like Calcium Ion Channel in the Filamentous Fungus Aspergillus nidulans. J Fungi (Basel) 2021; 7:jof7110920. [PMID: 34829209 PMCID: PMC8618638 DOI: 10.3390/jof7110920] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 10/25/2021] [Accepted: 10/27/2021] [Indexed: 11/16/2022] Open
Abstract
Transient Receptor Potential (TRP) proteins constitute a superfamily that encodes transmembrane ion channels with highly diverse permeation and gating properties. Filamentous fungi possess putative TRP channel-encoded genes, but their functions remain elusive. Here, we report that a putative TRP-like calcium channel, trpR, in the filamentous fungus Aspergillus nidulans, performs important roles in conidiation and in adapting to cell wall disruption reagents in a high temperature-induced defect-dependent manner, especially under a calcium-limited culture condition. The genetic and functional relationship between TrpR and the previously identified high-affinity calcium channels CchA/MidA indicates that TrpR has an opposite response to CchA/MidA when reacting to cell wall disruption reagents and in regulating calcium transients. However, a considerable addition of calcium can rescue all the defects that occur in TrpR and CchA/MidA, meaning that calcium is able to bypass the necessary requirement. Nevertheless, the colocalization at the membrane of the Golgi for TrpR and the P-type Golgi Ca2+ ATPase PmrA suggests two channels that may work as ion transporters, transferring Ca2+ from the cytosol into the Golgi apparatus and maintaining cellular calcium homeostasis. Therefore, combined with data for the trpR deletion mutant revealing abnormal cell wall structures, TrpR works as a Golgi membrane calcium ion channel that involves cell wall integration.
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Affiliation(s)
| | | | | | - Ling Lu
- Correspondence: (S.Z.); (L.L.)
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12
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Liu L, Yu B, Sun W, Liang C, Ying H, Zhou S, Niu H, Wang Y, Liu D, Chen Y. Calcineurin signaling pathway influences Aspergillus niger biofilm formation by affecting hydrophobicity and cell wall integrity. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:54. [PMID: 32190119 PMCID: PMC7075038 DOI: 10.1186/s13068-020-01692-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 03/02/2020] [Indexed: 05/14/2023]
Abstract
BACKGROUND Biofilms, as a kind of fixed-cell community, can greatly improve industrial fermentation efficiency in immobilized fermentation, but the regulation process is still unclear, which restricts their application. Ca2+ was reported to be a key factor affecting biofilm formation. However, the effect of Ca2+ on biofilm structure and microbiology was yet only studied in bacteria. How Ca2+-mediated calcineurin signaling pathway (CSP) alters biofilm formation in bacteria and fungi has rarely been reported. On this basis, we investigated the regulation of CSP on the formation of biofilm in Aspergillus niger. RESULTS Deletion of the key genes MidA, CchA, CrzA or CnaA in the CSP lowered the Ca2+ concentration in the mycelium to a different extent, inhibited the formation of A. niger biofilm, reduced the hydrophobicity and adhesion of spores, destroyed the cell wall integrity of hyphae, and reduced the flocculation ability of hyphae. qRT-PCR results showed that the expression of spore hydrophobic protein RodA, galactosaminogalactan (GAG) biosynthesis genes (uge3, uge5, agd3, gtb3), and α-1,3-glucan biosynthesis genes (ags1, ags3) in the ∆MidA, ∆CchA, ∆CrzA, ∆CnaA strains were significantly down-regulated compared with those of the wild type (WT). In addition, the transcription levels of the chitin synthesis gene (chsB, chsD) and β-1,3-glucan synthesis gene (FksA) were consistent with the change in chitin and β-1,3-glucan contents in mutant strains. CONCLUSION These results indicated that CSP affected the hydrophobicity and adhesion of spores, the integrity of mycelial cell walls and flocculation by affecting Ca2+ levels in mycelium, which in turn affected biofilm formation. This work provides a possible explanation for how CSP changes the formation of A. niger biofilm, and reveals a pathway for controlling biofilm formation in industrial immobilized fermentation.
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Affiliation(s)
- Li Liu
- National Engineering Research Center for Biotechnology, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816 People’s Republic of China
| | - Bin Yu
- National Engineering Research Center for Biotechnology, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816 People’s Republic of China
| | - Wenjun Sun
- National Engineering Research Center for Biotechnology, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816 People’s Republic of China
| | - Caice Liang
- National Engineering Research Center for Biotechnology, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816 People’s Republic of China
| | - Hanjie Ying
- National Engineering Research Center for Biotechnology, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816 People’s Republic of China
- School of Chemical Engineering and Energy, Zhengzhou University, Zhengzhou, 450001 China
| | - Shengmin Zhou
- State Key Laboratory of Bioreactor Engineering, School of Biotechnology, East China University of Science and Technology, Shanghai, 200237 China
| | - Huanqing Niu
- National Engineering Research Center for Biotechnology, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816 People’s Republic of China
| | - Yibing Wang
- State Key Laboratory of Bioreactor Engineering, School of Biotechnology, East China University of Science and Technology, Shanghai, 200237 China
| | - Dong Liu
- National Engineering Research Center for Biotechnology, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816 People’s Republic of China
- School of Chemical Engineering and Energy, Zhengzhou University, Zhengzhou, 450001 China
| | - Yong Chen
- National Engineering Research Center for Biotechnology, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816 People’s Republic of China
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13
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Zheng YQ, Pan KS, Latgé JP, Andrianopoulos A, Luo H, Yan RF, Wei JY, Huang CY, Cao CW. Calcineurin A Is Essential in the Regulation of Asexual Development, Stress Responses and Pathogenesis in Talaromyces marneffei. Front Microbiol 2020; 10:3094. [PMID: 32038542 PMCID: PMC6985273 DOI: 10.3389/fmicb.2019.03094] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Accepted: 12/20/2019] [Indexed: 11/27/2022] Open
Abstract
Talaromyces marneffei is a common cause of infection in immunocompromised patients in Southeast Asia and Southern China. The pathogenicity of T. marneffei depends on the ability of the fungus to survive the cytotoxic processes of the host immune system and grow inside host macrophages. These mechanisms that allow T. marneffei to survive macrophage-induced death are poorly understood. In this study, we examined the role of a calcineurin homolog (cnaA) from T. marneffei during growth, morphogenesis and infection. Deletion of the cnaA gene in T. marneffei resulted in a strain with significant defects in conidiation, germination, morphogenesis, cell wall integrity, and resistance to various stressors. The ΔcnaA mutant showed a lower minimal inhibitory concentration (MIC) against caspofungin (16 μg/ml to 2 μg/ml) and micafungin (from 32 μg/ml to 4 μg/ml) compared with the wild-type. These results suggest that targeting calcineurin in combination with echinocandin treatment may be effective for life-threatening systemic T. marneffei infection. Importantly, the cnaA mutant was incapable of adapting to the macrophage environment in vitro and displayed virulence defects in a mouse model of invasive talaromycosis. For the first time, a role has been shown for cnaA in the morphology and pathogenicity of a dimorphic pathogenic filamentous fungus.
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Affiliation(s)
- Yan-Qing Zheng
- Department of Dermatology and Venereology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Kai-Su Pan
- Department of Dermatology and Venereology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | | | - Alex Andrianopoulos
- School of Biosciences, The University of Melbourne, Parkville, VIC, Australia
| | - Hong Luo
- Department of Dermatology and Venereology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Ru-Fan Yan
- Department of Dermatology and Venereology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Jin-Ying Wei
- Department of Dermatology and Venereology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Chun-Yang Huang
- Department of Dermatology and Venereology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Cun-Wei Cao
- Department of Dermatology and Venereology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
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14
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Lange M, Peiter E. Calcium Transport Proteins in Fungi: The Phylogenetic Diversity of Their Relevance for Growth, Virulence, and Stress Resistance. Front Microbiol 2020; 10:3100. [PMID: 32047484 PMCID: PMC6997533 DOI: 10.3389/fmicb.2019.03100] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 12/20/2019] [Indexed: 12/26/2022] Open
Abstract
The key players of calcium (Ca2+) homeostasis and Ca2+ signal generation, which are Ca2+ channels, Ca2+/H+ antiporters, and Ca2+-ATPases, are present in all fungi. Their coordinated action maintains a low Ca2+ baseline, allows a fast increase in free Ca2+ concentration upon a stimulus, and terminates this Ca2+ elevation by an exponential decrease – hence forming a Ca2+ signal. In this respect, the Ca2+ signaling machinery is conserved in different fungi. However, does the similarity of the genetic inventory that shapes the Ca2+ peak imply that if “you’ve seen one, you’ve seen them all” in terms of physiological relevance? Individual studies have focused mostly on a single species, and mechanisms elucidated in few model organisms are usually extrapolated to other species. This mini-review focuses on the physiological relevance of the machinery that maintains Ca2+ homeostasis for growth, virulence, and stress responses. It reveals common and divergent functions of homologous proteins in different fungal species. In conclusion, for the physiological role of these Ca2+ transport proteins, “seen one,” in many cases, does not mean: “seen them all.”
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Affiliation(s)
- Mario Lange
- Plant Nutrition Laboratory, Institute of Agricultural and Nutritional Sciences, Faculty of Natural Sciences III, Martin Luther University of Halle-Wittenberg, Halle (Saale), Germany
| | - Edgar Peiter
- Plant Nutrition Laboratory, Institute of Agricultural and Nutritional Sciences, Faculty of Natural Sciences III, Martin Luther University of Halle-Wittenberg, Halle (Saale), Germany
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15
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Jansen RP, Beuck C, Moch M, Klein B, Küsters K, Morschett H, Wiechert W, Oldiges M. A closer look at Aspergillus: online monitoring via scattered light enables reproducible phenotyping. Fungal Biol Biotechnol 2019; 6:11. [PMID: 31396392 PMCID: PMC6681481 DOI: 10.1186/s40694-019-0073-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2019] [Accepted: 07/17/2019] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Filamentously growing microorganisms offer unique advantages for biotechnological processes, such as extraordinary secretion capacities, going along with multiple obstacles due to their complex morphology. However, limited experimental throughput in bioprocess development still hampers taking advantage of their full potential. Miniaturization and automation are powerful tools to accelerate bioprocess development, but so far the application of such technologies has mainly been focused on non-filamentous systems. During cultivation, filamentous fungi can undergo remarkable morphological changes, creating challenging cultivation conditions. Depending on the process and product, only one specific state of morphology may be advantageous to achieve e.g. optimal productivity or yield. Different approaches to control morphology have been investigated, such as microparticle enhanced cultivation. However, the addition of solid microparticles impedes the optical measurements typically used by microbioreactor systems and thus alternatives are needed. RESULTS Aspergillus giganteus IfGB 0902 was used as a model system to develop a time-efficient and robust workflow allowing microscale cultivation with increased throughput. The effect of microtiter plate geometry, shaking frequency and medium additives (talc and calcium chloride) on homogeneity of culture morphology as well as reproducibility were analyzed via online biomass measurement, microscopic imaging and cell dry weight. While addition of talc severely affected online measurements, 2% (w v-1) calcium chloride was successfully applied to obtain a highly reproducible growth behavior with homogenous morphology. Furthermore, the influence of small amounts of complex components was investigated for the applied model strain. By correlation to cell dry weight, it could be shown that optical measurements are a suitable signal for biomass concentration. However, each correlation is only applicable for a specific set of cultivation parameters. These optimized conditions were used in micro as well as lab-scale bioreactor cultivation in order to verify the reproducibility and scalability of the setup. CONCLUSION A robust workflow for A. giganteus was developed, allowing for reproducible microscale cultivation with online monitoring, where calcium chloride is an useful alternative to microparticle enhanced cultivation in order to control the morphology. Independent of the cultivation volume, comparable phenotypes were observed in microtiter plates and in lab-scale bioreactor.
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Affiliation(s)
- Roman P. Jansen
- Forschungszentrum Jülich, Institute of Bio- and Geosciences-Biotechnology (IBG-1), Jülich, Germany
| | - Carina Beuck
- Forschungszentrum Jülich, Institute of Bio- and Geosciences-Biotechnology (IBG-1), Jülich, Germany
| | - Matthias Moch
- Forschungszentrum Jülich, Institute of Bio- and Geosciences-Biotechnology (IBG-1), Jülich, Germany
| | - Bianca Klein
- Forschungszentrum Jülich, Institute of Bio- and Geosciences-Biotechnology (IBG-1), Jülich, Germany
| | - Kira Küsters
- Forschungszentrum Jülich, Institute of Bio- and Geosciences-Biotechnology (IBG-1), Jülich, Germany
| | - Holger Morschett
- Forschungszentrum Jülich, Institute of Bio- and Geosciences-Biotechnology (IBG-1), Jülich, Germany
| | - Wolfgang Wiechert
- Forschungszentrum Jülich, Institute of Bio- and Geosciences-Biotechnology (IBG-1), Jülich, Germany
- Computational Systems Biotechnology (AVT.CSB), RWTH Aachen University, Aachen, Germany
| | - Marco Oldiges
- Forschungszentrum Jülich, Institute of Bio- and Geosciences-Biotechnology (IBG-1), Jülich, Germany
- Institute of Biotechnology, RWTH Aachen University, Aachen, Germany
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16
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Veerana M, Lim JS, Choi EH, Park G. Aspergillus oryzae spore germination is enhanced by non-thermal atmospheric pressure plasma. Sci Rep 2019; 9:11184. [PMID: 31371801 PMCID: PMC6673704 DOI: 10.1038/s41598-019-47705-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 07/22/2019] [Indexed: 12/15/2022] Open
Abstract
Poor and unstable culture growth following isolation presents a technical barrier to the efficient application of beneficial microorganisms in the food industry. Non-thermal atmospheric pressure plasma is an effective tool that could overcome this barrier. The objective of this study was to investigate the potential of plasma to enhance spore germination, the initial step in fungal colonization, using Aspergillus oryzae, a beneficial filamentous fungus used in the fermentation industry. Treating fungal spores in background solutions of phosphate buffered saline (PBS) and potato dextrose broth (PDB) with micro dielectric barrier discharge plasma using nitrogen gas for 2 and 5 min, respectively, significantly increased the germination percentage. Spore swelling, the first step in germination, was accelerated following plasma treatment, indicating that plasma may be involved in loosening the spore surface. Plasma treatment depolarized spore membranes, elevated intracellular Ca2+ levels, and activated mpkA, a MAP kinase, and the transcription of several germination-associated genes. Our results suggest that plasma enhances fungal spore germination by stimulating spore swelling, depolarizing the cell membrane, and activating calcium and MAPK signaling.
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Affiliation(s)
- Mayura Veerana
- Plasma Bioscience Research Center, Kwangwoon University, Seoul, 01897, Korea.,Department of Plasma Bioscience and Display, Kwangwoon University, Seoul, 01897, Korea
| | - Jun-Sup Lim
- Department of Electrical and Biological Physics, Kwangwoon University, Seoul, 01897, Korea
| | - Eun-Ha Choi
- Plasma Bioscience Research Center, Kwangwoon University, Seoul, 01897, Korea.,Department of Plasma Bioscience and Display, Kwangwoon University, Seoul, 01897, Korea.,Department of Electrical and Biological Physics, Kwangwoon University, Seoul, 01897, Korea
| | - Gyungsoon Park
- Plasma Bioscience Research Center, Kwangwoon University, Seoul, 01897, Korea. .,Department of Plasma Bioscience and Display, Kwangwoon University, Seoul, 01897, Korea. .,Department of Electrical and Biological Physics, Kwangwoon University, Seoul, 01897, Korea.
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17
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Li Y, Zhang Y, Lu L. Calcium signaling pathway is involved in non-CYP51 azole resistance in Aspergillus fumigatus. Med Mycol 2019; 57:S233-S238. [PMID: 30816964 DOI: 10.1093/mmy/myy075] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 07/05/2018] [Accepted: 09/03/2018] [Indexed: 12/20/2022] Open
Abstract
The opportunistic fungal pathogen Aspergillus fumigatus, which is one of the primary airborne ascomycete pathogens and allergens worldwide, causes invasive fungal infections, which have high morbidity and mortality rates among immunosuppressed patients. The abuse of azole antifungals results in serious drug resistance in clinical therapy. Thus, a thorough understanding of the azole drug resistance mechanism and screening of antifungal agents with a novel mode of action and new drug targets are required to fight against drug resistance. Current studies suggest that there are three major azole resistance mechanisms in fungal pathogens, including changes of the drug target Cyp51, activation of drug efflux pumps and induction of cellular stress responses. Fungi must adapt to a variety of external environmental stressors to survive. These obstacles include stress to the plasma membrane after azole antifungal treatments, high temperature, pH variation, and oxidative stress. As a filamentous fungus, A. fumigatus has evolved numerous signal-transduction systems to sense and respond to azole stresses to survive and proliferate in harsh environmental conditions. Among these signal-transduction systems, the Ca2+ signaling pathway is one of the most important response systems, which has been verified to be involved in stress adaptation. In this review, we have summarized how the components of the calcium-signaling pathway and their interaction network are involved in azole stress response in A. fumigatus.
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Affiliation(s)
- Yeqi Li
- Jiangsu Key laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China
| | - Yuanwei Zhang
- Jiangsu Key laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China
| | - Ling Lu
- Jiangsu Key laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China
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18
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Manoli MT, Espeso EA. Modulation of calcineurin activity in Aspergillus nidulans: the roles of high magnesium concentrations and of transcriptional factor CrzA. Mol Microbiol 2019; 111:1283-1301. [PMID: 30741447 DOI: 10.1111/mmi.14221] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/05/2019] [Indexed: 01/31/2023]
Abstract
A proper response to elevated extracellular calcium levels helps to most organisms to keep this secondary messenger under strict control, thereby preventing inadequate activation or inhibition of many regulatory activities into cells. In fungi, the calcineurin responsive zinc-finger Crz1/CrzA transcription factor transduces calcium signaling to gene expression. In Aspergillus nidulans, absence of CrzA activity leads to alkaline pH sensitivity and loss of tolerance to high levels of extracellular calcium. Disruption of calcium uptake mechanisms or the presence of high levels of Mg2+ partially suppresses this calcium-sensitive phenotype of null crzA strain. The effects of Mg2+ on CrzA phosphorylation and perturbations that reduce calcineurin phosphatase activity on CrzA demonstrate that the calcium sensitive phenotype of null crzA strain is a consequence of up-regulated calcineurin activity under calcium-induced conditions.
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Affiliation(s)
- Maria-Tsampika Manoli
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas (CIB), CSIC, Ramiro de Maeztu, 9, Madrid, 28040, Spain
| | - Eduardo A Espeso
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas (CIB), CSIC, Ramiro de Maeztu, 9, Madrid, 28040, Spain
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19
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Mid1 affects ion transport, cell wall integrity, and host penetration of the entomopathogenic fungus Metarhizium acridum. Appl Microbiol Biotechnol 2019; 103:1801-1810. [PMID: 30617534 DOI: 10.1007/s00253-018-09589-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 12/10/2018] [Accepted: 12/14/2018] [Indexed: 01/01/2023]
Abstract
Calcium signaling plays important roles in stress tolerance and virulence in fungi. Mid1, an accessory protein of Cch1 calcium channel, has been discussed in baker's yeast and some filamentous fungi. However, functions of the Mid1 gene in entomopathogenic fungi are not clear. In this study, the Mid1 gene was functionally characterized by deleting it in the entomopathogenic fungus Metarhizium acridum. The growth of the ΔMaMid1 mutant was similar as the wild type on normal growth medium, but inhibited by exogenous Ca2+, Fe2+, Mg2+, Mn2+, Li+, and calcium chelator ethylene glycol tetraacetic acid (EGTA). Cation transportation-related genes were upregulated and intracellular calcium concentration was decreased in ΔMaMid1. Deletion of the MaMid1 gene impaired the tolerance to cell wall-disrupting agents but had no impact on heat or ultraviolet irradiation tolerance compared with the wild type. Bioassays showed that ΔMaMid1 had decreased virulence, with defects in the ability to penetrate the host cuticle. Compared with the wild type, appressorium formation on locust wings and fungal growth in the insect hemocoel were significantly decreased in the ΔMaMid1 mutant in a bioassay through topical inoculation. The phenotypes of ΔMaMid1 were fully restored in a complementation strain. Taken together, our study demonstrates that the MaMid1 affects intracellular ion homeostasis and contributes to virulence by affecting the initial penetration process in M. acridum.
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20
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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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21
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Kontár S, Varečka L, Híreš M, Kryštofová S, Šimkovič M. Light-induced conidiation of Trichoderma spp. strains is accompanied by development-dependent changes in the Ca 2+ binding to cell walls. Can J Microbiol 2018; 64:856-864. [PMID: 29906398 DOI: 10.1139/cjm-2017-0747] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The effect of light on the binding of Ca2+ to mycelia and to cell walls isolated from aerial mycelia of three strains of Trichoderma spp. was studied. Two independent methods were used to measure the total Ca2+ content in mycelia and the Ca2+ bound to cell walls isolated from aerial mycelia. The results of these methods showed that the light-induced formation and maturation of conidia in Trichoderma spp. is accompanied by increased Ca2+ deposition in mycelia and cell walls. Moreover, the cultivation of Trichoderma atroviride F-534 in the presence of 45Ca2+ under circadian illumination showed that radioactivity was exclusively localized in the light-induced conidial rings of aerial mycelia. The fluorescence microscopy of chlortetracycline-stained mycelia showed that the major fraction of Ca2+ was accumulated in conidia and fructification structures, or some intracellular compartments in T. atroviride F-534 grown under circadian illumination, while only a limited amount of Ca2+ was associated with hyphal surfaces. In addition, the study of 45Ca2+ binding to cell walls revealed that T. atroviride F-534 displays both increased 45Ca2+ binding capacity and elevated affinity to 45Ca2+ binding upon illumination. The results indicate that conidia formation and (or) maturation is associated with changes in Ca2+ homeostasis.
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Affiliation(s)
- Szilvia Kontár
- a Institute of Biochemistry and Microbiology, Faculty of Chemical and Food Technology, Slovak University of Technology, Bratislava, Slovak Republic.,b Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Bratislava, Slovak Republic
| | - L'udovít Varečka
- a Institute of Biochemistry and Microbiology, Faculty of Chemical and Food Technology, Slovak University of Technology, Bratislava, Slovak Republic
| | - Michal Híreš
- a Institute of Biochemistry and Microbiology, Faculty of Chemical and Food Technology, Slovak University of Technology, Bratislava, Slovak Republic
| | - Svetlana Kryštofová
- a Institute of Biochemistry and Microbiology, Faculty of Chemical and Food Technology, Slovak University of Technology, Bratislava, Slovak Republic
| | - Martin Šimkovič
- a Institute of Biochemistry and Microbiology, Faculty of Chemical and Food Technology, Slovak University of Technology, Bratislava, Slovak Republic
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22
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Qian H, Chen Q, Zhang S, Lu L. The Claudin Family Protein FigA Mediates Ca 2+ Homeostasis in Response to Extracellular Stimuli in Aspergillus nidulans and Aspergillus fumigatus. Front Microbiol 2018; 9:977. [PMID: 29867880 PMCID: PMC5962676 DOI: 10.3389/fmicb.2018.00977] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 04/25/2018] [Indexed: 11/16/2022] Open
Abstract
The claudin family protein Fig1 is a unique fungal protein that is involved in pheromone-induced calcium influx and membrane fusion during the mating of Saccharomyces cerevisiae and Candida albicans. Whether and how Fig1 regulates Ca2+ homeostasis in response to extracellular stimuli is poorly understood. Previously, we found Aspergillus nidulans FigA, a homolog of Fig1 in S. cerevisiae, similar to the high-affinity calcium uptake system, is required for normal growth under low-Ca2+ minimal medium. In this study, using the calcium-sensitive photoprotein aequorin to monitor cytosolic free calcium concentration ([Ca2+]c) in living cells, we found that the FigA dysfunction decreases the transient [Ca2+]c induced by a high extracellular calcium stress. Furthermore, FigA acts synergistically with CchA (a high-affinity Ca2+ channel) to coordinate cytoplasmic Ca2+ influx in response to an extracellular Ca2+ stimulus. Moreover, FigA mediates ER stress-induced transient [Ca2+]c in the presence or absence of extracellular calcium. Most importantly, these [Ca2+]c responses mediated by FigA are closely related to its conserved claudin superfamily motif, which is also required for hyphal growth and asexual development in A. nidulans. Finally, the function of FigA in Aspergillus fumigatus, the most common airborne human fungal pathogen was studied. The result showed that the two FigA homologous in A. nidulans and A. fumigatus have a large degree of functional homology not only in asexual development but also in regulating transient [Ca2+]c. Our study expands the knowledge of claudin family protein FigA in Ca2+ homeostasis in response to extracellular stimuli.
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Affiliation(s)
- Hui Qian
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Qiuyi Chen
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Shizhu Zhang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Ling Lu
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China
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Oscillatory fungal cell growth. Fungal Genet Biol 2017; 110:10-14. [PMID: 29229585 DOI: 10.1016/j.fgb.2017.12.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Revised: 11/26/2017] [Accepted: 12/06/2017] [Indexed: 12/20/2022]
Abstract
Cells are dynamic systems, the state of which undergoes constant alteration that results in morphological changes and movement. Many dynamic cellular processes that appear continuous are driven by underlying mechanisms that oscillate with distinct periods. For example eukaryotic cells do not grow continuously, but rather by pulsed extension of the periphery. Stepwise cell extension at the hyphal tips of several filamentous fungi was discovered 20 years ago, but only a few molecular details of the mechanism have been clarified since then. A recent study has provided evidence for correlations among intracellular Ca2+ levels, actin assembly, exocytosis and cell extension 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. The coordinated oscillation of these machineries are likely to be ubiquitous among all eukaryotes. Indeed, intracellular Ca2+ levels and/or actin polymerization oscillate in mammalian and plant cells. This review summarizes the mechanisms of oscillation in several systems.
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Kim HS, Kim JE, Son H, Frailey D, Cirino R, Lee YW, Duncan R, Czymmek KJ, Kang S. Roles of three Fusarium graminearum membrane Ca 2+ channels in the formation of Ca 2+ signatures, growth, development, pathogenicity and mycotoxin production. Fungal Genet Biol 2017; 111:30-46. [PMID: 29175365 DOI: 10.1016/j.fgb.2017.11.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 11/11/2017] [Accepted: 11/15/2017] [Indexed: 02/06/2023]
Abstract
Similar to animals and plants, external stimuli cause dynamic spatial and temporal changes of cytoplasmic Ca2+ in fungi. Such changes are referred as the Ca2+ signature and control cellular responses by modulating the activity or location of diverse Ca2+-binding proteins (CBPs) and also indirectly affecting proteins that interact with CBPs. To understand the mechanism underpinning Ca2+ signaling, therefore, characterization of how Ca2+ moves to and from the cytoplasm to create Ca2+ signatures under different conditions is fundamental. Three genes encoding plasma membrane Ca2+ channels in a Fusarium graminearum strain that expresses a fluorescent protein-based Ca2+ indicator in the cytoplasm were mutagenized to investigate their roles in the generation of Ca2+ signatures under different growth conditions and genetic backgrounds. The genes disrupted include CCH1 and MID1, which encode a high affinity Ca2+ uptake system, and FIG1, encoding a low affinity Ca2+ channel. Resulting mutants were also analyzed for growth, development, pathogenicity and mycotoxin production to determine how loss of each of the genes alters these traits. To investigate whether individual genes influence the function and expression of other genes, phenotypes and Ca2+ signatures of their double and triple mutants, as well as their expression patterns, were analyzed.
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Affiliation(s)
- Hye-Seon Kim
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA; Delaware Biotechnology Institute, Newark, DE 19711, USA
| | - Jung-Eun Kim
- Department of Plant Pathology & Environmental Microbiology, Pennsylvania State University, University Park, PA 16802, USA
| | - Hokyoung Son
- Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Daniel Frailey
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - Robert Cirino
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - Yin-Won Lee
- Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Randall Duncan
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - Kirk J Czymmek
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA; Delaware Biotechnology Institute, Newark, DE 19711, USA
| | - Seogchan Kang
- Department of Plant Pathology & Environmental Microbiology, Pennsylvania State University, University Park, PA 16802, USA.
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Transcriptomic Analysis Reveals Genes Mediating Salt Tolerance through Calcineurin/CchA-Independent Signaling in Aspergillus nidulans. BIOMED RESEARCH INTERNATIONAL 2017; 2017:4378627. [PMID: 28904958 PMCID: PMC5585587 DOI: 10.1155/2017/4378627] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 06/01/2017] [Accepted: 07/10/2017] [Indexed: 01/11/2023]
Abstract
Adaptation to changes in the environment is crucial for the viability of all organisms. Although the importance of calcineurin in the stress response has been highlighted in filamentous fungi, little is known about the involvement of ion-responsive genes and pathways in conferring salt tolerance without calcium signaling. In this study, high-throughput RNA-seq was used to investigate salt stress-induced genes in the parent, ΔcnaB, and ΔcnaBΔcchA strains of Aspergillus nidulans, which differ greatly in salt adaption. In total, 2,884 differentially expressed genes including 1,382 up- and 1,502 downregulated genes were identified. Secondary transporters, which were upregulated to a greater extent in ΔcnaBΔcchA than in the parent or ΔcnaB strains, are likely to play important roles in response to salt stress. Furthermore, 36 genes were exclusively upregulated in the ΔcnaBΔcchA under salt stress. Functional analysis of differentially expressed genes revealed that genes involved in transport, heat shock protein binding, and cell division processes were exclusively activated in ΔcnaBΔcchA. Overall, our findings reveal that secondary transporters and stress-responsive genes may play crucial roles in salt tolerance to bypass the requirement for the CchA-calcineurin pathway, contributing to a deeper understanding of the mechanisms that influence fungal salt stress adaption in Aspergillus.
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The Lectin Chaperone Calnexin Is Involved in the Endoplasmic Reticulum Stress Response by Regulating Ca 2+ Homeostasis in Aspergillus nidulans. Appl Environ Microbiol 2017; 83:AEM.00673-17. [PMID: 28550061 DOI: 10.1128/aem.00673-17] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 05/18/2017] [Indexed: 12/23/2022] Open
Abstract
The Ca2+-mediated signaling pathway is crucial for environmental adaptation in fungi. Here we show that calnexin, a molecular chaperone located in the endoplasmic reticulum (ER), plays an important role in regulating the cytosolic free calcium concentration ([Ca2+]c) in Aspergillus nidulans Inactivation of calnexin (ClxA) in A. nidulans caused severe defects in hyphal growth and conidiation under ER stress caused by the ER stress-inducing agent dithiothreitol (DTT) or high temperature. Importantly, defects in the ΔclxA mutant were restored by the addition of extracellular calcium. Furthermore, the CchA/MidA complex (the high-affinity Ca2+ channels), calcineurin (calcium/calmodulin-dependent protein phosphatase), and PmrA (secretory pathway Ca2+ ATPase) were required for extracellular calcium-based restoration of the DTT/thermal stress sensitivity in the ΔclxA mutant. Interestingly, the ΔclxA mutant exhibited markedly reduced conidium formation and hyphal growth defects under the low-calcium condition, which is similar to defects caused by mutations in MidA/CchA. Moreover, the phenotypic defects were further exacerbated in the ΔclxA ΔmidA ΔcchA mutant, which suggested that ClxA and MidA/CchA are both required under the calcium-limiting condition. Using the calcium-sensitive photoprotein aequorin to monitor [Ca2+]c in living cells, we found that ClxA and MidA/CchA complex synergistically coordinate transient increase in [Ca2+]c in response to extracellular calcium. Moreover, ClxA, in particular its luminal domain, plays a role in mediating the transient [Ca2+]c in response to DTT-induced ER stress in the absence of extracellular calcium, indicating ClxA may mediate calcium release from internal calcium stores. Our findings provide new insights into the role of calnexin in the regulation of calcium-mediated response in fungal ER stress adaptation.IMPORTANCE Calnexin is a well-known molecular chaperone conserved from yeast to humans. Although it contains calcium binding domains, little is known about the role of calnexin in Ca2+ regulation. In this study, we demonstrate that calnexin (ClxA) in the filamentous fungus Aspergillus nidulans, similar to the high-affinity calcium uptake system (HACS), is required for normal growth and conidiation under the calcium-limiting condition. The ClxA dysfunction decreases the transient cytosolic free calcium concentration ([Ca2+]c) induced by a high extracellular calcium or DTT-induced ER stress. Our findings provide the direct evidence that calnexin plays important roles in regulating Ca2+ homeostasis in addition to its role as a molecular chaperone in fungi. These results provide new insights into the roles of calnexin and expand knowledge of fungal stress adaptation.
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Pulses of Ca 2+ coordinate actin assembly and exocytosis for stepwise cell extension. Proc Natl Acad Sci U S A 2017; 114:5701-5706. [PMID: 28507141 DOI: 10.1073/pnas.1700204114] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Many eukaryotic cells grow by extending their cell periphery in pulses. The molecular mechanisms underlying this process are not yet fully understood. Here we present a comprehensive model of stepwise cell extension by using the unique tip growth system of filamentous fungi. Live-cell imaging analysis, including superresolution microscopy, revealed that the fungus Aspergillus nidulans extends the hyphal tip in an oscillatory manner. The amount of F-actin and secretory vesicles (SV) accumulating at the hyphal tip oscillated with a positive temporal correlation, whereas vesicle amounts were negatively correlated to the growth rate. The intracellular Ca2+ level also pulsed with a positive temporal correlation to the amount of F-actin and SV at the hyphal tip. Two Ca2+ channels, MidA and CchA, were needed for proper tip growth and the oscillations of actin polymerization, exocytosis, and the growth rate. The data indicate a model in which transient Ca2+ pluses cause depolymerization of F-actin at the cortex and promote SV fusion with the plasma membrane, thereby extending the cell tip. Over time, Ca2+ diffuses away and F-actin and SV accumulate again at the hyphal tip. Our data provide evidence that temporally controlled actin polymerization and exocytosis are coordinated by pulsed Ca2+ influx, resulting in stepwise cell extension.
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28
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Hwu FY, Lai MW, Liou RF. PpMID1 Plays a Role in the Asexual Development and Virulence of Phytophthora parasitica. Front Microbiol 2017; 8:610. [PMID: 28469602 PMCID: PMC5395580 DOI: 10.3389/fmicb.2017.00610] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 03/27/2017] [Indexed: 01/01/2023] Open
Abstract
Phytophthora parasitica is a notorious oomycete pathogen that causes severe disease in a wide variety of crop species. Infection of plants involves mainly its asexual life stage, including papillate sporangia and biflagellated zoospores, which are the primary dispersal and infection agents of this pathogen. Calcium signaling has been thought as the key regulator for sporangium formation and zoospore differentiation. However, not much is known about the molecular players involved in these processes. In Saccharomyces cerevisiae, mating pheromone-induced death 1 (MID1) encodes a component of a putative calcium channel. Here, we identified and characterized the function of PpMID1, an MID1 homolog from P. parasitica. The expression of PpMID1 was high in sporangia. Gene silencing of PpMID1 resulted in the formation of sporangia that lacked papilla and showed a tendency for direct germination. Notably, in response to cold shock to induce zoospore formation, these sporangia showed no sign of cytoplasmic cleavage and thereby failed to form zoospores. Nonetheless, the addition of CaCl2 or MgCl2 partially recovered the silenced sporangia phenotype, with the formation of papillate sporangia similar to those of the wild type and the release of zoospores upon cold shock. As well, virulence toward Nicotiana benthamiana was reduced in the PpMID1-silenced transformants. These results indicate a role of PpMID1 in the asexual development and virulence of P. parasitica.
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Affiliation(s)
- Fang-Yu Hwu
- Department of Plant Pathology and Microbiology, National Taiwan UniversityTaipei, Taiwan
| | - Ming-Wei Lai
- Department of Plant Pathology and Microbiology, National Taiwan UniversityTaipei, Taiwan
| | - Ruey-Fen Liou
- Department of Plant Pathology and Microbiology, National Taiwan UniversityTaipei, Taiwan
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Screening and Characterization of a Non-cyp51A Mutation in an Aspergillus fumigatus cox10 Strain Conferring Azole Resistance. Antimicrob Agents Chemother 2016; 61:AAC.02101-16. [PMID: 27799210 DOI: 10.1128/aac.02101-16] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 10/18/2016] [Indexed: 12/14/2022] Open
Abstract
The rapid and global emergence of azole resistance in the human pathogen Aspergillus fumigatus has drawn attention. Thus, a thorough understanding of its mechanisms of drug resistance requires extensive exploration. In this study, we found that the loss of the putative calcium-dependent protein-encoding gene algA causes an increased frequency of azole-resistant A. fumigatus isolates. In contrast to previously identified azole-resistant isolates related to cyp51A mutations, only one isolate carries a point mutation in cyp51A (F219L mutation) among 105 independent stable azole-resistant isolates. Through next-generation sequencing (NGS), we successfully identified a new mutation (R243Q substitution) conferring azole resistance in the putative A. fumigatus farnesyltransferase Cox10 (AfCox10) (AFUB_065450). High-performance liquid chromatography (HPLC) analysis verified that the decreased absorption of itraconazole in related Afcox10 mutants is the primary reason for itraconazole resistance. Moreover, a complementation experiment by reengineering the mutation in a parental wild-type background strain demonstrated that both the F219L and R243Q mutations contribute to itraconazole resistance in an algA-independent manner. These data collectively suggest that the loss of algA results in an increased frequency of azole-resistant isolates with a non-cyp51A mutation. Our findings indicate that there are many unexplored non-cyp51A mutations conferring azole resistance in A. fumigatus and that algA defects make it possible to isolate drug-resistant alleles. In addition, our study suggests that genome-wide sequencing combined with alignment comparison analysis is an efficient approach to identify the contribution of single nucleotide polymorphism (SNP) diversity to drug resistance.
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30
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Saxena A, Sitaraman R. Osmoregulation in Saccharomyces cerevisiae via mechanisms other than the high-osmolarity glycerol pathway. Microbiology (Reading) 2016; 162:1511-1526. [DOI: 10.1099/mic.0.000360] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Abhishek Saxena
- Department of Biotechnology, TERI University, New Delhi, India
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Liu P, Gong J, Ding X, Jiang Y, Chen G, Li B, Weng Q, Chen Q. The L-type Ca(2+) Channel Blocker Nifedipine Inhibits Mycelial Growth, Sporulation, and Virulence of Phytophthora capsici. Front Microbiol 2016; 7:1236. [PMID: 27540377 PMCID: PMC4972815 DOI: 10.3389/fmicb.2016.01236] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 07/25/2016] [Indexed: 11/19/2022] Open
Abstract
The oomycete vegetable pathogen Phytophthora capsici causes significant losses of important vegetable crops worldwide. Calcium and other plant nutrients have been used in disease management of oomycete pathogens. Calcium homeostasis and signaling is essential for numerous biological processes, and Ca(2+) channel blockers prevent excessive Ca(2+) influx into the fungal cell. However, it is not known whether voltage-gated Ca(2+) channel blockers improve control over oomycete pathogens. In the present study, we compared the inhibitory effects of CaCl2 and the extracellular Ca(2+) chelator EDTA on mycelial growth and found that calcium assimilation plays a key role in P. capsici mycelial growth. Next, we involved the voltage-gated Ca(2+) channel blockers verapamil (VP) and nifedipine (NFD) to analyze the effect of Ca(2+) channel blockers on mycelial growth and sporulation; the results suggested that NFD, but not VP, caused significant inhibition. Ion rescue in an NFD-induced inhibition assay suggested that NFD-induced inhibition is calcium-dependent. In addition, NFD increased P. capsici sensitivity to H2O2 in a calcium-dependent manner, and extracellular calcium rescued it. Furthermore, NFD inhibited the virulence and gene expression related to its pathogenicity. These results suggest that NFD inhibits mycelial growth, sporulation, and virulence of P. capsici.
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Affiliation(s)
| | | | | | | | | | | | - Qiyong Weng
- Fujian Key Laboratory for Monitoring and Integrated Management of Crop Pests, Institute of Plant Protection, Fujian Academy of Agricultural SciencesFuzhou, China
| | - Qinghe Chen
- Fujian Key Laboratory for Monitoring and Integrated Management of Crop Pests, Institute of Plant Protection, Fujian Academy of Agricultural SciencesFuzhou, China
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32
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Gupta P, Chanda R, Rai N, Kataria VK, Kumar N. Antihypertensive, Amlodipine Besilate Inhibits Growth and Biofilm of Human Fungal Pathogen Candida. Assay Drug Dev Technol 2016; 14:291-297. [DOI: 10.1089/adt.2016.714] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Affiliation(s)
- Payal Gupta
- Department of Biotechnology, Graphic Era University, Dehradun, India
| | - Reshmi Chanda
- Department of Microbiology, Shri Guru Ram Rai Institute of Medical and Health Sciences, Dehradun, India
| | - Nishant Rai
- Department of Biotechnology, Graphic Era University, Dehradun, India
| | - Vijay K. Kataria
- Department of Microbiology, Shri Guru Ram Rai Institute of Medical and Health Sciences, Dehradun, India
| | - Navin Kumar
- Department of Biotechnology, Graphic Era University, Dehradun, India
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Lange M, Weihmann F, Schliebner I, Horbach R, Deising HB, Wirsel SGR, Peiter E. The Transient Receptor Potential (TRP) Channel Family in Colletotrichum graminicola: A Molecular and Physiological Analysis. PLoS One 2016; 11:e0158561. [PMID: 27359114 PMCID: PMC4928787 DOI: 10.1371/journal.pone.0158561] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 06/19/2016] [Indexed: 12/02/2022] Open
Abstract
Calcium (Ca2+) is a universal second messenger in all higher organisms and centrally involved in the launch of responses to environmental stimuli. Ca2+ signals in the cytosol are initiated by the activation of Ca2+ channels in the plasma membrane and/or in endomembranes. Yeast (Saccharomyces cerevisiae) contains a Ca2+-permeable channel of the TRP family, TRPY1, which is localized in the vacuolar membrane and contributes to cytosolic free Ca2+ ([Ca2+]cyt) elevations, for example in response to osmotic upshock. A TRPY1 homologue in the rice blast fungus is known to be important for growth and pathogenicity. To determine the role of the TRP channel family in the maize pathogen Colletotrichum graminicola, proteins homologous to TRPY1 were searched. This identified not one, but four genes in the C. graminicola genome, which had putative orthologs in other fungi, and which we named CgTRPF1 through 4. The topology of the CgTRPF proteins resembled that of TRPY1, albeit with a variable number of transmembrane (TM) domains additional to the six-TM-domain core and a diverse arrangement of putatively Ca2+-binding acidic motifs. All CgTRPF genes were expressed in axenic culture and throughout the infection of maize. Like TRPY1, all TRPF proteins of C. graminicola were localized intracellularly, albeit three of them were found not in large vacuoles, but co-localized in vesicular structures. Deletion strains for the CgTRPF genes were not altered in processes thought to involve Ca2+ release from internal stores, i.e. spore germination, the utilization of complex carbon sources, and the generation of tip-focussed [Ca2+]cyt spikes. Heterologous expression of CgTRPF1 through 4 in a tryp1Δ yeast mutant revealed that none of the channels mediated the release of Ca2+ in response to osmotic upshock. Accordingly, aequorin-based [Ca2+]cyt measurements of C. graminicola showed that in this fungus, osmotic upshock-triggered [Ca2+]cyt elevations were generated entirely by influx of Ca2+ from the extracellular space. Cgtrpf mutants did not show pathogenicity defects in leaf infection assays. In summary, our study reveals major differences between different fungi in the contribution of TRP channels to Ca2+-mediated signal transduction.
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Affiliation(s)
- Mario Lange
- Plant Nutrition Laboratory, Institute of Agricultural and Nutritional Sciences (IAEW), Faculty of Natural Sciences III, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
- Interdisciplinary Centre for Crop Plant Research (IZN), Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Fabian Weihmann
- Phytopathology and Plant Protection, Institute of Agricultural and Nutritional Sciences (IAEW), Faculty of Natural Sciences III, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Ivo Schliebner
- Phytopathology and Plant Protection, Institute of Agricultural and Nutritional Sciences (IAEW), Faculty of Natural Sciences III, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
- Interdisciplinary Centre for Crop Plant Research (IZN), Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Ralf Horbach
- Phytopathology and Plant Protection, Institute of Agricultural and Nutritional Sciences (IAEW), Faculty of Natural Sciences III, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
- Interdisciplinary Centre for Crop Plant Research (IZN), Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Holger B. Deising
- Phytopathology and Plant Protection, Institute of Agricultural and Nutritional Sciences (IAEW), Faculty of Natural Sciences III, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
- Interdisciplinary Centre for Crop Plant Research (IZN), Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Stefan G. R. Wirsel
- Phytopathology and Plant Protection, Institute of Agricultural and Nutritional Sciences (IAEW), Faculty of Natural Sciences III, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
- Interdisciplinary Centre for Crop Plant Research (IZN), Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Edgar Peiter
- Plant Nutrition Laboratory, Institute of Agricultural and Nutritional Sciences (IAEW), Faculty of Natural Sciences III, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
- Interdisciplinary Centre for Crop Plant Research (IZN), Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
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Calcineurin and Calcium Channel CchA Coordinate the Salt Stress Response by Regulating Cytoplasmic Ca2+ Homeostasis in Aspergillus nidulans. Appl Environ Microbiol 2016; 82:3420-3430. [PMID: 27037124 DOI: 10.1128/aem.00330-16] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 03/28/2016] [Indexed: 11/20/2022] Open
Abstract
The eukaryotic calcium/calmodulin-dependent protein phosphatase calcineurin is crucial for the environmental adaption of fungi. However, the mechanism of coordinate regulation of the response to salt stress by calcineurin and the high-affinity calcium channel CchA in fungi is not well understood. Here we show that the deletion of cchA suppresses the hyphal growth defects caused by the loss of calcineurin under salt stress in Aspergillus nidulans Additionally, the hypersensitivity of the ΔcnaA strain to extracellular calcium and cell-wall-damaging agents can be suppressed by cchA deletion. Using the calcium-sensitive photoprotein aequorin to monitor the cytoplasmic Ca(2+) concentration ([Ca(2+)]c) in living cells, we found that calcineurin negatively regulates CchA on calcium uptake in response to external calcium in normally cultured cells. However, in salt-stress-pretreated cells, loss of either cnaA or cchA significantly decreased the [Ca(2+)]c, but a deficiency in both cnaA and cchA switches the [Ca(2+)]c to the reference strain level, indicating that calcineurin and CchA synergistically coordinate calcium influx under salt stress. Moreover, real-time PCR results showed that the dysfunction of cchA in the ΔcnaA strain dramatically restored the expression of enaA (a major determinant for sodium detoxification), which was abolished in the ΔcnaA strain under salt stress. These results suggest that double deficiencies of cnaA and cchA could bypass the requirement of calcineurin to induce enaA expression under salt stress. Finally, YvcA, a member of the transient receptor potential channel (TRPC) protein family of vacuolar Ca(2+) channels, was proven to compensate for calcineurin-CchA in fungal salt stress adaption.IMPORTANCE The feedback inhibition relationship between calcineurin and the calcium channel Cch1/Mid1 has been well recognized from yeast. Interestingly, our previous study (S. Wang et al., PLoS One 7:e46564, 2012, http://dx.doi.org/10.1371/journal.pone.0046564) showed that the deletion of cchA could suppress the hyphal growth defects caused by the loss of calcineurin under salt stress in Aspergillus nidulans In this study, our findings suggest that fungi are able to develop a unique mechanism for adapting to environmental salt stress. Compared to cells cultured normally, the NaCl-pretreated cells had a remarkable increase in transient [Ca(2+)]c Furthermore, we show that calcineurin and CchA are required to modulate cellular calcium levels and synergistically coordinate calcium influx under salt stress. Finally, YvcA, a member of of the TRPC family of vacuolar Ca(2+) channels, was proven to compensate for calcineurin-CchA in fungal salt stress adaption. The findings in this study provide insights into the complex regulatory links between calcineurin and CchA to maintain cytoplasmic Ca(2+) homeostasis in response to different environments.
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Zhang Y, Zheng Q, Sun C, Song J, Gao L, Zhang S, Muñoz A, Read ND, Lu L. Palmitoylation of the Cysteine Residue in the DHHC Motif of a Palmitoyl Transferase Mediates Ca2+ Homeostasis in Aspergillus. PLoS Genet 2016; 12:e1005977. [PMID: 27058039 PMCID: PMC4825924 DOI: 10.1371/journal.pgen.1005977] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 03/15/2016] [Indexed: 01/08/2023] Open
Abstract
Finely tuned changes in cytosolic free calcium ([Ca2+]c) mediate numerous intracellular functions resulting in the activation or inactivation of a series of target proteins. Palmitoylation is a reversible post-translational modification involved in membrane protein trafficking between membranes and in their functional modulation. However, studies on the relationship between palmitoylation and calcium signaling have been limited. Here, we demonstrate that the yeast palmitoyl transferase ScAkr1p homolog, AkrA in Aspergillus nidulans, regulates [Ca2+]c homeostasis. Deletion of akrA showed marked defects in hyphal growth and conidiation under low calcium conditions which were similar to the effects of deleting components of the high-affinity calcium uptake system (HACS). The [Ca2+]c dynamics in living cells expressing the calcium reporter aequorin in different akrA mutant backgrounds were defective in their [Ca2+]c responses to high extracellular Ca2+ stress or drugs that cause ER or plasma membrane stress. All of these effects on the [Ca2+]c responses mediated by AkrA were closely associated with the cysteine residue of the AkrA DHHC motif, which is required for palmitoylation by AkrA. Using the acyl-biotin exchange chemistry assay combined with proteomic mass spectrometry, we identified protein substrates palmitoylated by AkrA including two new putative P-type ATPases (Pmc1 and Spf1 homologs), a putative proton V-type proton ATPase (Vma5 homolog) and three putative proteins in A. nidulans, the transcripts of which have previously been shown to be induced by extracellular calcium stress in a CrzA-dependent manner. Thus, our findings provide strong evidence that the AkrA protein regulates [Ca2+]c homeostasis by palmitoylating these protein candidates and give new insights the role of palmitoylation in the regulation of calcium-mediated responses to extracellular, ER or plasma membrane stress. Palmitoylation is a reversible post-translational modification catalyzed by palmitoyl acyltransferases (PATs) and proteins that undergo this modification are involved in numerous intracellular functions. Yeast Akr1p was the first characterized PAT whilst HIP14, an Akr1p homolog in human, is one of the most highly conserved of 23 human PATs that catalyze the addition of palmitate to the Huntington protein which is of major importance in Huntington’s disease. Calcium serves numerous signaling and structural functions in all eukaryotes. However, studies on the relationship between calcium signaling and palmitoylation are lacking. In this study, we demonstrate that the palmitoyl transferase Akr1 homolog in the filamentous fungus Aspergillus nidulans, similar to the high-affinity calcium uptake system (HACS), is required for normal growth and sporulation in the presence of low extracellular calcium. We find that AkrA dysfunction decreases the transient increase in cytosolic free calcium induced by a high extracellular calcium stress, tunicamycin (which induces endoplasmic reticulum stress) or the antifungal agent itraconazole (which induces plasma membrane stress). The influence of AkrA on all of these processes involves its DHHC motif, which is required for palmitoylation of various proteins associated with many processes including calcium signaling and membrane trafficking. Our findings provide evidence for a crucial link between calcium signaling and palmitoylation, suggesting a possible role in the mechanistic basis of human PAT-related diseases. These results also indicate that regulators of posttranslational modification may provide promising antifungal targets for new therapies.
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Affiliation(s)
- Yuanwei Zhang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology; College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Qingqing Zheng
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology; College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Congcong Sun
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology; College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Jinxing Song
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology; College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Lina Gao
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology; College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Shizhu Zhang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology; College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Alberto Muñoz
- Manchester Fungal Infection Group, Institute of Inflammation and Repair, University of Manchester, Manchester, United Kingdom
| | - Nick D. Read
- Manchester Fungal Infection Group, Institute of Inflammation and Repair, University of Manchester, Manchester, United Kingdom
| | - Ling Lu
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology; College of Life Sciences, Nanjing Normal University, Nanjing, China
- * E-mail:
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Chen L, Zou G, Wang J, Wang J, Liu R, Jiang Y, Zhao G, Zhou Z. Characterization of the Ca2+-responsive signaling pathway in regulating the expression and secretion of cellulases inTrichoderma reeseiRut-C30. Mol Microbiol 2016; 100:560-75. [DOI: 10.1111/mmi.13334] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/21/2016] [Indexed: 11/28/2022]
Affiliation(s)
- Ling Chen
- Key Laboratory of Synthetic Biology; Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences; Shanghai 200032 China
| | - Gen Zou
- Key Laboratory of Synthetic Biology; Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences; Shanghai 200032 China
| | - Jingzhi Wang
- Key Laboratory of Synthetic Biology; Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences; Shanghai 200032 China
| | - Jin Wang
- Key Laboratory of Synthetic Biology; Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences; Shanghai 200032 China
| | - Rui Liu
- Key Laboratory of Synthetic Biology; Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences; Shanghai 200032 China
| | - Yanping Jiang
- Key Laboratory of Synthetic Biology; Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences; Shanghai 200032 China
| | - Guoping Zhao
- Key Laboratory of Synthetic Biology; Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences; Shanghai 200032 China
| | - Zhihua Zhou
- Key Laboratory of Synthetic Biology; Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences; Shanghai 200032 China
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Xiao L, Lian B, Dong C, Liu F. The selective expression of carbonic anhydrase genes of Aspergillus nidulans in response to changes in mineral nutrition and CO2 concentration. Microbiologyopen 2016; 5:60-9. [PMID: 26553629 PMCID: PMC4767425 DOI: 10.1002/mbo3.311] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 09/25/2015] [Accepted: 10/06/2015] [Indexed: 12/21/2022] Open
Abstract
Carbonic anhydrase (CA) plays an important role in the formation and evolution of life. However, to our knowledge, there has been no report on CA isoenzyme function differentiation in fungi. Two different CA gene sequences in Aspergillus nidulans with clear genetic background provide us a favorable basis for studying function differentiation of CA isoenzymes. Heterologously expressed CA1 was used to test its weathering ability on silicate minerals and real-time quantitative PCR was used to detect expression of the CA1 and CA2 genes at different CO2 concentrations and in the presence of different potassium sources. The northern blot method was applied to confirm the result of CA1 gene expression. Heterologously expressed CA1 significantly promoted dissolution of biotite and wollastonite, and CA1 gene expression increased significantly in response to soluble K-deficiency. The northern blot test further showed that CA1 participated in K-feldspar weathering. In addition, the results showed that CA2 was primary involved in adapting to CO2 concentration change. Taken together, A. nidulans can choose different CA to meet their survival needs, which imply that some environmental microbes have evolved different CAs to adapt to changes in CO2 concentration and acquire mineral nutrition so that they can better adapt to environmental changes. Inversely, their adaption may impact mineral weathering and/or CO2 concentration, and even global change.
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Affiliation(s)
- Leilei Xiao
- Jiangsu Key Laboratory for Microbes and Functional GenomicsJiangsu Engineering and Technology Research Center for MicrobiologyCollege of Life SciencesNanjing Normal UniversityNanjing210023China
- Key Laboratory of Coastal Environmental Processes and Ecological RemediationYantai Institute of Coastal Zone ResearchChinese Academy of SciencesYantai264003China
| | - Bin Lian
- Jiangsu Key Laboratory for Microbes and Functional GenomicsJiangsu Engineering and Technology Research Center for MicrobiologyCollege of Life SciencesNanjing Normal UniversityNanjing210023China
| | - Cuiling Dong
- Jiangsu Key Laboratory for Microbes and Functional GenomicsJiangsu Engineering and Technology Research Center for MicrobiologyCollege of Life SciencesNanjing Normal UniversityNanjing210023China
| | - Fanghua Liu
- Key Laboratory of Coastal Environmental Processes and Ecological RemediationYantai Institute of Coastal Zone ResearchChinese Academy of SciencesYantai264003China
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Kim HS, Kim JE, Frailey D, Nohe A, Duncan R, Czymmek KJ, Kang S. Roles of three Fusarium oxysporum calcium ion (Ca2+) channels in generating Ca2+ signatures and controlling growth. Fungal Genet Biol 2015; 82:145-57. [DOI: 10.1016/j.fgb.2015.07.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Revised: 06/30/2015] [Accepted: 07/06/2015] [Indexed: 12/31/2022]
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Calcium signaling mediates antifungal activity of triazole drugs in the Aspergilli. Fungal Genet Biol 2015; 81:182-90. [DOI: 10.1016/j.fgb.2014.12.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Revised: 12/15/2014] [Accepted: 12/18/2014] [Indexed: 01/01/2023]
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Components of the calcium-calcineurin signaling pathway in fungal cells and their potential as antifungal targets. EUKARYOTIC CELL 2015; 14:324-34. [PMID: 25636321 DOI: 10.1128/ec.00271-14] [Citation(s) in RCA: 119] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
In recent years, the emergence of fungal resistance has become frequent, partly due to the widespread clinical use of fluconazole, which is minimally toxic and effective in the prevention and treatment of Candida albicans infections. The limited selection of antifungal drugs for clinical fungal infection therapy has prompted us to search for new antifungal drug targets. Calcium, which acts as the second messenger in both mammals and fungi, plays a direct role in controlling the expression patterns of its signaling systems and has important roles in cell survival. In addition, calcium and some of the components, mainly calcineurin, in the fungal calcium signaling pathway mediate fungal resistance to antifungal drugs. Therefore, an overview of the components of the fungal calcium-calcineurin signaling network and their potential roles as antifungal targets is urgently needed. The calcium-calcineurin signaling pathway consists of various channels, transporters, pumps, and other proteins or enzymes. Many transcriptional profiles have indicated that mutant strains that lack some of these components are sensitized to fluconazole or other antifungal drugs. In addition, many researchers have identified efficient compounds that exhibit antifungal activity by themselves or in combination with antifungal drugs by targeting some of the components in the fungal calcium-calcineurin signaling pathway. This targeting disrupts Ca(2+) homeostasis, which suggests that this pathway contains potential targets for the development of new antifungal drugs.
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Juvvadi PR, Lamoth F, Steinbach WJ. Calcineurin as a Multifunctional Regulator: Unraveling Novel Functions in Fungal Stress Responses, Hyphal Growth, Drug Resistance, and Pathogenesis. FUNGAL BIOL REV 2014; 28:56-69. [PMID: 25383089 DOI: 10.1016/j.fbr.2014.02.004] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Calcineurin signaling plays diverse roles in fungi in regulating stress responses, morphogenesis and pathogenesis. Although calcineurin signaling is conserved among fungi, recent studies indicate important divergences in calcineurin-dependent cellular functions among different human fungal pathogens. Fungal pathogens utilize the calcineurin pathway to effectively survive the host environment and cause life-threatening infections. The immunosuppressive calcineurin inhibitors (FK506 and cyclosporine A) are active against fungi, making targeting calcineurin a promising antifungal drug development strategy. Here we summarize current knowledge on calcineurin in yeasts and filamentous fungi, and review the importance of understanding fungal-specific attributes of calcineurin to decipher fungal pathogenesis and develop novel antifungal therapeutic approaches.
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Affiliation(s)
- Praveen R Juvvadi
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Duke University Medical Center, Durham NC, USA
| | - Frédéric Lamoth
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Duke University Medical Center, Durham NC, USA ; Infectious Diseases Service, Department of Medicine, Lausanne University Hospital, Lausanne, Switzerland ; Institute of Microbiology, Lausanne University Hospital, Lausanne, Switzerland
| | - 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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Jiang H, Liu F, Zhang S, Lu L. Putative PmrA and PmcA are important for normal growth, morphogenesis and cell wall integrity, but not for viability in Aspergillus nidulans. MICROBIOLOGY-SGM 2014; 160:2387-2395. [PMID: 25118249 DOI: 10.1099/mic.0.080119-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
P-type Ca(2+)-transporting ATPases are Ca(2+) pumps, extruding cytosolic Ca(2+) to the extracellular environment or the intracellular Ca(2+) store lumens. In budding yeast, Pmr1 (plasma membrane ATPase related), and Pmc1 (plasma membrane calcium-ATPase) cannot be deleted simultaneously for it to survive in standard medium. Here, we deleted two putative Ca(2+) pumps, designated AnPmrA and AnPmcA, from Aspergillus nidulans, and obtained the mutants ΔanpmrA and ΔanpmcA, respectively. Then, using ΔanpmrA as the starting strain, the promoter of its anpmcA was replaced with the alcA promoter to secure the mutant ΔanpmrAalcApmcA or its anpmcA was deleted completely to produce the mutant ΔanpmrAΔpmcA. Different from the case in Saccharomyces cerevisiae, double deletion of anpmrA and anpmcA was not lethal in A. nidulans. In addition, deletion of anpmrA and/or anpmcA had produced growth defects, although overexpression of AnPmc1 in ΔanpmrAalcApmcA could not restore the growth defects that resulted from the loss of AnPmrA. Moreover, we found AnPmrA was indispensable for maintenance of normal morphogenesis, especially in low-Ca(2+)/Mn(2+) environments. Thus, our findings suggest AnPmrA and AnPmcA might play important roles in growth, morphogenesis and cell wall integrity in A. nidulans in a different way from that in yeasts.
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Affiliation(s)
- Hechun Jiang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology; College of Life Sciences, Nanjing Normal University, Nanjing 210023, PR China
| | - Feifei Liu
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology; College of Life Sciences, Nanjing Normal University, Nanjing 210023, PR China
| | - Shizhu Zhang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology; College of Life Sciences, Nanjing Normal University, Nanjing 210023, PR China
| | - Ling Lu
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology; College of Life Sciences, Nanjing Normal University, Nanjing 210023, PR China
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de Castro PA, Chiaratto J, Winkelströter LK, Bom VLP, Ramalho LNZ, Goldman MHS, Brown NA, Goldman GH. The involvement of the Mid1/Cch1/Yvc1 calcium channels in Aspergillus fumigatus virulence. PLoS One 2014; 9:e103957. [PMID: 25083783 PMCID: PMC4118995 DOI: 10.1371/journal.pone.0103957] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Accepted: 07/03/2014] [Indexed: 11/30/2022] Open
Abstract
Aspergillus fumigatus is a major opportunistic pathogen and allergen of mammals. Calcium homeostasis and signaling is essential for numerous biological processes and also influences A. fumigatus pathogenicity. The presented study characterized the function of the A. fumigatus homologues of three Saccharomyces cerevisiae calcium channels, voltage-gated Cch1, stretch-activated Mid1 and vacuolar Yvc1. The A. fumigatus calcium channels cchA, midA and yvcA were regulated at transcriptional level by increased calcium levels. The YvcA::GFP fusion protein localized to the vacuoles. Both ΔcchA and ΔmidA mutant strains showed reduced radial growth rate in nutrient-poor minimal media. Interestingly, this growth defect in the ΔcchA strain was rescued by the exogenous addition of CaCl2. The ΔcchA, ΔmidA, and ΔcchA ΔmidA strains were also sensitive to the oxidative stress inducer, paraquat. Restriction of external Ca2+ through the addition of the Ca2+-chelator EGTA impacted upon the growth of the ΔcchA and ΔmidA strains. All the A. fumigatus ΔcchA, ΔmidA, and ΔyvcA strains demonstrated attenuated virulence in a neutropenic murine model of invasive pulmonary aspergillosis. Infection with the parental strain resulted in a 100% mortality rate at 15 days post-infection, while the mortality rate of the ΔcchA, ΔmidA, and ΔyvcA strains after 15 days post-infection was only 25%. Collectively, this investigation strongly indicates that CchA, MidA, and YvcA play a role in A. fumigatus calcium homeostasis and virulence.
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Affiliation(s)
- Patrícia Alves de Castro
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Jéssica Chiaratto
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Lizziane K. Winkelströter
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Vinícius Leite Pedro Bom
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | | | - Maria Helena S. Goldman
- Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Neil Andrew Brown
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Gustavo H. Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
- National Laboratory of Science and Technology of Bioethanol (CTBE), Campinas, Brazil
- * E-mail:
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Jiang H, Shen Y, Liu W, Lu L. Deletion of the putative stretch-activated ion channel Mid1 is hypervirulent in Aspergillus fumigatus. Fungal Genet Biol 2014; 62:62-70. [DOI: 10.1016/j.fgb.2013.11.003] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Revised: 11/04/2013] [Accepted: 11/07/2013] [Indexed: 12/22/2022]
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FigA, a putative homolog of low-affinity calcium system member Fig1 in Saccharomyces cerevisiae, is involved in growth and asexual and sexual development in Aspergillus nidulans. EUKARYOTIC CELL 2013; 13:295-303. [PMID: 24376003 DOI: 10.1128/ec.00257-13] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Calcium-mediated signaling pathways are widely employed in eukaryotes and are implicated in the regulation of diverse biological processes. In Saccharomyces cerevisiae, at least two different calcium uptake systems have been identified: the high-affinity calcium influx system (HACS) and the low-affinity calcium influx system (LACS). Compared to the HACS, the LACS in fungi is not well known. In this study, FigA, a homolog of the LACS member Fig1 from S. cerevisiae, was functionally characterized in the filamentous fungus Aspergillus nidulans. Loss of figA resulted in retardant hyphal growth and a sharp reduction of conidial production. Most importantly, FigA is essential for the homothallic mating (self-fertilization) process; further, FigA is required for heterothallic mating (outcrossing) in the absence of HACS midA. Interestingly, in a figA deletion mutant, adding extracellular Ca(2+) rescued the hyphal growth defects but could not restore asexual and sexual reproduction. Furthermore, quantitative PCR results revealed that figA deletion sharply decreased the expression of brlA and nsdD, which are known as key regulators during asexual and sexual development, respectively. In addition, green fluorescent protein (GFP) tagging at the C terminus of FigA (FigA::GFP) showed that FigA localized to the center of the septum in mature hyphal cells, to the location between vesicles and metulae, and between the junctions of metulae and phialides in conidiophores. Thus, our findings suggest that FigA, apart from being a member of a calcium uptake system in A. nidulans, may play multiple unexplored roles during hyphal growth and asexual and sexual development.
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Cch1 and Mid1 are functionally required for vegetative growth under low-calcium conditions in the phytopathogenic ascomycete Botrytis cinerea. EUKARYOTIC CELL 2013; 12:712-24. [PMID: 23475703 DOI: 10.1128/ec.00338-12] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
In the filamentous phytopathogen Botrytis cinerea, the Ca(2+)/calcineurin signaling cascade has been shown to play an important role in fungal growth, differentiation, and virulence. This study deals with the functional characterization of two components of this pathway, the putative calcium channel proteins Cch1 and Mid1. The cch1 and mid1 genes were deleted, and single and double knockout mutants were analyzed during different stages of the fungal life cycle. Our data indicate that Cch1 and Mid1 are functionally required for vegetative growth under conditions of low extracellular calcium, since the growth of both deletion mutants is strongly impaired when they are exposed to the Ca(2+)-chelating agents EGTA and 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA). The impact of external Ca(2+) was investigated by supplementing with CaCl(2) and the ionophore A23187, both of which resulted in elevated growth for all mutants. However, deletion of either gene had no impact on germination, sporulation, hyphal morphology, or virulence. By use of the aequorin reporter system to measure intracellular calcium levels, no differences between the mutant strains and the wild type were obtained. Localization studies revealed a subcellular distribution of the Mid1-green fluorescent protein (GFP) fusion protein in network-like filaments, probably the endoplasmic reticulum (ER) membranes, indicating that Mid1 is not a plasma membrane-located calcium channel in B. cinerea.
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