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Yuan Z, Li P, Yang X, Cai X, Wu L, Zhao F, Wen W, Zhou M, Hou Y. FgPfn participates in vegetative growth, sexual reproduction, pathogenicity, and fungicides sensitivity via affecting both microtubules and actin in the filamentous fungus Fusarium graminearum. PLoS Pathog 2024; 20:e1012215. [PMID: 38701108 PMCID: PMC11095717 DOI: 10.1371/journal.ppat.1012215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 05/15/2024] [Accepted: 04/23/2024] [Indexed: 05/05/2024] Open
Abstract
Fusarium head blight (FHB), caused by Fusarium graminearum species complexes (FGSG), is an epidemic disease in wheat and poses a serious threat to wheat production and security worldwide. Profilins are a class of actin-binding proteins that participate in actin depolymerization. However, the roles of profilins in plant fungal pathogens remain largely unexplored. Here, we identified FgPfn, a homolog to profilins in F. graminearum, and the deletion of FgPfn resulted in severe defects in mycelial growth, conidia production, and pathogenicity, accompanied by marked disruptions in toxisomes formation and deoxynivalenol (DON) transport, while sexual development was aborted. Additionally, FgPfn interacted with Fgα1 and Fgβ2, the significant components of microtubules. The organization of microtubules in the ΔFgPfn was strongly inhibited under the treatment of 0.4 μg/mL carbendazim, a well-known group of tubulin interferers, resulting in increased sensitivity to carbendazim. Moreover, FgPfn interacted with both myosin-5 (FgMyo5) and actin (FgAct), the targets of the fungicide phenamacril, and these interactions were reduced after phenamacril treatment. The deletion of FgPfn disrupted the normal organization of FgMyo5 and FgAct cytoskeleton, weakened the interaction between FgMyo5 and FgAct, and resulting in increased sensitivity to phenamacril. The core region of the interaction between FgPfn and FgAct was investigated, revealing that the integrity of both proteins was necessary for their interaction. Furthermore, mutations in R72, R77, R86, G91, I101, A112, G113, and D124 caused the non-interaction between FgPfn and FgAct. The R86K, I101E, and D124E mutants in FgPfn resulted in severe defects in actin organization, development, and pathogenicity. Taken together, this study revealed the role of FgPfn-dependent cytoskeleton in development, DON production and transport, fungicides sensitivity in F. graminearum.
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Affiliation(s)
- Zhili Yuan
- College of Plant Protection, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Pengfei Li
- College of Plant Protection, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Xin Yang
- College of Plant Protection, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Xiaowei Cai
- College of Plant Protection, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Luoyu Wu
- College of Plant Protection, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Feifei Zhao
- College of Plant Protection, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Weidong Wen
- College of Plant Protection, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Mingguo Zhou
- College of Plant Protection, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Yiping Hou
- College of Plant Protection, Nanjing Agricultural University, Nanjing, Jiangsu, China
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2
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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:e0005724. [PMID: 38687129 DOI: 10.1128/msphere.00057-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [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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Vasselli JG, Kainer E, Shaw BD. Using fimbrin to quantify the endocytic subapical collar during polarized growth in three filamentous fungi. Mycologia 2023:1-14. [PMID: 37196171 DOI: 10.1080/00275514.2023.2202689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 04/09/2023] [Indexed: 05/19/2023]
Abstract
Filamentous fungi produce specialized cells called hyphae. These cells grow by polarized extension at their apex, which is maintained by the balance of endocytosis and exocytosis at the apex. Although endocytosis has been well characterized in other organisms, the details of endocytosis and its role in maintaining polarity during hyphal growth in filamentous fungi is comparatively sparsely studied. In recent years, a concentrated region of protein activity that trails the growing apex of hyphal cells has been discovered. This region, dubbed the "endocytic collar" (EC), is a dynamic 3-dimensional region of concentrated endocytic activity, the disruption of which results in the loss of hyphal polarity. Here, fluorescent protein-tagged fimbrin was used as a marker to map the collar during growth of hyphae in three fungi: Aspergillus nidulans, Colletotrichum graminicola, and Neurospora crassa. Advanced microscopy techniques and novel quantification strategies were then utilized to quantify the spatiotemporal localization and recovery rates of fimbrin in the EC during hyphal growth. Correlating these variables with hyphal growth rate revealed that the strongest observed relationship with hyphal growth is the distance by which the EC trails the apex, and that measured endocytic rate does not correlate strongly with hyphal growth rate. This supports the hypothesis that endocytic influence on hyphal growth rate is better explained by spatiotemporal regulation of the EC than by the raw rate of endocytosis.
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Affiliation(s)
- Joseph G Vasselli
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas 77843
| | - Ellen Kainer
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas 77843
| | - Brian D Shaw
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas 77843
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Zhang Y, An B, Wang W, Zhang B, He C, Luo H, Wang Q. Actin-bundling protein fimbrin regulates pathogenicity via organizing F-actin dynamics during appressorium development in Colletotrichum gloeosporioides. MOLECULAR PLANT PATHOLOGY 2022; 23:1472-1486. [PMID: 35791045 PMCID: PMC9452767 DOI: 10.1111/mpp.13242] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 06/12/2022] [Accepted: 06/14/2022] [Indexed: 06/15/2023]
Abstract
Anthracnose caused by Colletotrichum gloeosporioides leads to serious economic loss to rubber tree yield and other tropical crops. The appressorium, a specialized dome-shaped infection structure, plays a crucial role in the pathogenesis of C. gloeosporioides. However, the mechanism of how actin cytoskeleton dynamics regulate appressorium formation and penetration remains poorly defined in C. gloeosporioides. In this study, an actin cross-linking protein fimbrin homologue (CgFim1) was identified in C. gloeosporioides, and the knockout of CgFim1 led to impairment in vegetative growth, conidiation, and pathogenicity. We then investigated the roles of CgFim1 in the dynamic organization of the actin cytoskeleton. We observed that actin patches and cables localized at the apical and subapical regions of the hyphal tip, and showed a disc-to-ring dynamic around the pore during appressorium development. CgFim1 showed a similar distribution pattern to the actin cytoskeleton. Moreover, knockout of CgFim1 affected the polarity of the actin cytoskeleton in the hyphal tip and disrupted the actin dynamics and ring structure formation in the appressorium, which prevented polar growth and appressorium development. The CgFim1 mutant also interfered with the septin structure formation. This caused defects in pore wall overlay formation, pore contraction, and the extension of the penetration peg. These results reveal the mechanism by which CgFim1 regulates the growth and pathogenicity of C. gloeosporioides by organizing the actin cytoskeleton.
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Affiliation(s)
- Yi Zhang
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresource, Key Laboratory of Biotechnology of Salt Tolerant Crops of Hainan ProvinceCollege of Tropical Crops, Hainan UniversityHaikouChina
- Sanya Nanfan Research Institute of Hainan University, Hainan Yazhou Bay Seed LaboratorySanyaChina
| | - Bang An
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresource, Key Laboratory of Biotechnology of Salt Tolerant Crops of Hainan ProvinceCollege of Tropical Crops, Hainan UniversityHaikouChina
- Sanya Nanfan Research Institute of Hainan University, Hainan Yazhou Bay Seed LaboratorySanyaChina
| | - Wenfeng Wang
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresource, Key Laboratory of Biotechnology of Salt Tolerant Crops of Hainan ProvinceCollege of Tropical Crops, Hainan UniversityHaikouChina
| | - Bei Zhang
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresource, Key Laboratory of Biotechnology of Salt Tolerant Crops of Hainan ProvinceCollege of Tropical Crops, Hainan UniversityHaikouChina
- Sanya Nanfan Research Institute of Hainan University, Hainan Yazhou Bay Seed LaboratorySanyaChina
| | - Chaozu He
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresource, Key Laboratory of Biotechnology of Salt Tolerant Crops of Hainan ProvinceCollege of Tropical Crops, Hainan UniversityHaikouChina
- Sanya Nanfan Research Institute of Hainan University, Hainan Yazhou Bay Seed LaboratorySanyaChina
| | - Hongli Luo
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresource, Key Laboratory of Biotechnology of Salt Tolerant Crops of Hainan ProvinceCollege of Tropical Crops, Hainan UniversityHaikouChina
- Sanya Nanfan Research Institute of Hainan University, Hainan Yazhou Bay Seed LaboratorySanyaChina
| | - Qiannan Wang
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresource, Key Laboratory of Biotechnology of Salt Tolerant Crops of Hainan ProvinceCollege of Tropical Crops, Hainan UniversityHaikouChina
- Sanya Nanfan Research Institute of Hainan University, Hainan Yazhou Bay Seed LaboratorySanyaChina
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5
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Liu N, Wang W, He C, Luo H, An B, Wang Q. NADPH Oxidases Play a Role in Pathogenicity via the Regulation of F-Actin Organization in Colletotrichum gloeosporioides. Front Cell Infect Microbiol 2022; 12:845133. [PMID: 35782153 PMCID: PMC9240266 DOI: 10.3389/fcimb.2022.845133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 05/16/2022] [Indexed: 11/29/2022] Open
Abstract
Multiunit-flavoenzyme NADPH oxidases (NOXs) play multiple roles in living cells via regulating signaling pathways. In several phytopathogenic fungi, NOXs are required for the polarized growth of hyphal tips and pathogenicity to host plants, but the possible mechanisms are still elusive. In our previous study, CgNOXA, CgNOXB, and CgNOXR were identified as components of the NOX complex in Colletotrichum gloeosporioides. The growth and the inoculation assays revealed that CgNOXA/B and CgNOXR regulate vegetative growth and are required for the full pathogenicity of C. gloeosporioides to Hevea leaves. We further demonstrated that the vital roles of CgNOXB and CgNOXR in appressorium formation and the development of invasion hyphae account for their functions in pathogenicity. Moreover, CgNOXB and CgNOXR regulate the production and distribution of ROS in hyphal tips and appressoria, control the specialized remodeling of F-actin in hyphal tips and appressoria, and are involved in fungal cell wall biosynthesis. Taken together, our findings highlight the role of NOXs in fungal pathogenicity through the organization of the actin cytoskeleton.
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Affiliation(s)
- Na Liu
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresource, College of Tropical Crops, Hainan University, Haikou, China
- Sanya Nanfan Research Institute of Hainan University, Hainan Yazhou Bay Seed Laboratory, Sanya, China
| | - Wenfeng Wang
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresource, College of Tropical Crops, Hainan University, Haikou, China
| | - Chaozu He
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresource, College of Tropical Crops, Hainan University, Haikou, China
- Sanya Nanfan Research Institute of Hainan University, Hainan Yazhou Bay Seed Laboratory, Sanya, China
| | - Hongli Luo
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresource, College of Tropical Crops, Hainan University, Haikou, China
- Sanya Nanfan Research Institute of Hainan University, Hainan Yazhou Bay Seed Laboratory, Sanya, China
| | - Bang An
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresource, College of Tropical Crops, Hainan University, Haikou, China
- Sanya Nanfan Research Institute of Hainan University, Hainan Yazhou Bay Seed Laboratory, Sanya, China
| | - Qiannan Wang
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresource, College of Tropical Crops, Hainan University, Haikou, China
- Sanya Nanfan Research Institute of Hainan University, Hainan Yazhou Bay Seed Laboratory, Sanya, China
- *Correspondence: Qiannan Wang,
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6
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Shigeto S, Takeshita N. Raman Micro-spectroscopy and Imaging of Filamentous Fungi. Microbes Environ 2022; 37. [PMID: 35387945 PMCID: PMC10037093 DOI: 10.1264/jsme2.me22006] [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] [Indexed: 11/12/2022] Open
Abstract
Filamentous fungi grow by the elongation of tubular cells called hyphae and form mycelia through repeated hyphal tip growth and branching. Since hyphal growth is closely related to the ability to secrete large amounts of enzymes or invade host cells, a more detailed understanding and the control of its growth are important in fungal biotechnology, ecology, and pathogenesis. Previous studies using fluorescence imaging revealed many of the molecular mechanisms involved in hyphal growth. Raman microspectroscopy and imaging methods are now attracting increasing attention as powerful alternatives due to their high chemical specificity and label-free, non-destructive properties. Spatially resolved information on the relative abundance, structure, and chemical state of multiple intracellular components may be simultaneously obtained. Although Raman studies on filamentous fungi are still limited, this review introduces recent findings from Raman studies on filamentous fungi and discusses their potential use in the future.
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Affiliation(s)
- Shinsuke Shigeto
- Department of Chemistry, School of Science, Kwansei Gakuin University
| | - Norio Takeshita
- Microbiology Research Center for Sustainability (MiCS), Faculty of Life and Environmental Sciences, University of Tsukuba
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7
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Hiasa R, Kakimoto KI, Takegawa K, Higuchi Y. Involvement of AAA ATPase AipA in endocytosis of the arginine permease AoCan1 depending on AoAbp1 in Aspergillus oryzae. Fungal Biol 2021; 126:149-161. [DOI: 10.1016/j.funbio.2021.11.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 11/16/2021] [Accepted: 11/22/2021] [Indexed: 11/17/2022]
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Jin J, Iwama R, Takagi K, Horiuchi H. AP-2 complex contributes to hyphal-tip-localization of a chitin synthase in the filamentous fungus Aspergillus nidulans. Fungal Biol 2021; 125:806-814. [PMID: 34537176 DOI: 10.1016/j.funbio.2021.05.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 05/06/2021] [Accepted: 05/18/2021] [Indexed: 10/20/2022]
Abstract
Filamentous fungi maintain hyphal growth to continually internalize membrane proteins related to cell wall synthesis, transporting them to the hyphal tips. Endocytosis mediates protein internalization via target recognition by the adaptor protein 2 complex (AP-2 complex). The AP-2 complex specifically promotes the internalization of proteins important for hyphal growth, and loss of AP-2 complex function results in abnormal hyphal growth. In this study, deletion mutants of the genes encoding the subunits of the AP-2 complex (α, β2, μ2, or σ2) in the filamentous fungus Aspergillus nidulans resulted in the formation of conidiophores with abnormal morphology, fewer conidia, and activated the cell wall integrity pathway. We also investigated the localization of ChsB, which plays pivotal roles in hyphal growth in A. nidulans, in the Δμ2 strain. Quantitative analysis suggested that the AP-2 complex is involved in ChsB internalization at subapical collar regions. The absence of the AP-2 complex reduced ChsB localization at the hyphal tips. Our findings suggest that the AP-2 complex contributes to cell wall integrity by properly localizing ChsB to the hyphal tips.
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Affiliation(s)
- Jingyun Jin
- Department of Biotechnology, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Ryo Iwama
- Department of Biotechnology, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo, 113-8657, Japan; Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Keiko Takagi
- Department of Biotechnology, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Hiroyuki Horiuchi
- Department of Biotechnology, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo, 113-8657, Japan; Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo, 113-8657, Japan.
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9
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Higuchi Y. Membrane traffic related to endosome dynamics and protein secretion in filamentous fungi. Biosci Biotechnol Biochem 2021; 85:1038-1045. [PMID: 33686391 DOI: 10.1093/bbb/zbab004] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 12/29/2020] [Indexed: 12/27/2022]
Abstract
In eukaryotic cells, membrane-surrounded organelles are orchestrally organized spatiotemporally under environmental situations. Among such organelles, vesicular transports and membrane contacts occur to communicate each other, so-called membrane traffic. Filamentous fungal cells are highly polarized and thus membrane traffic is developed to have versatile functions. Early endosome (EE) is an endocytic organelle that dynamically exhibits constant long-range motility through the hyphal cell, which is proven to have physiological roles, such as other organelle distribution and signal transduction. Since filamentous fungal cells are also considered as cell factories, to produce valuable proteins extracellularly, molecular mechanisms of secretory pathway including protein glycosylation have been well investigated. In this review, molecular and physiological aspects of membrane traffic especially related to EE dynamics and protein secretion in filamentous fungi are summarized, and perspectives for application are also described.
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Affiliation(s)
- Yujiro Higuchi
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka, Japan
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10
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Lingo DE, Shukla N, Osmani AH, Osmani SA. Aspergillus nidulans biofilm formation modifies cellular architecture and enables light-activated autophagy. Mol Biol Cell 2021; 32:1181-1192. [PMID: 33826367 PMCID: PMC8351559 DOI: 10.1091/mbc.e20-11-0734] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
After growing on surfaces, including those of medical and industrial importance, fungal biofilms self-generate internal microenvironments. We previously reported that gaseous microenvironments around founder Aspergillus nidulans cells change during biofilm formation causing microtubules to disassemble under control of the hypoxic transcription factor SrbA. Here we investigate if biofilm formation might also promote changes to structures involved in exocytosis and endocytosis. During biofilm formation, the endoplasmic reticulum (ER) remained intact but ER exit sites and the Golgi apparatus were modified as were endocytic actin patches. The biofilm-driven changes required the SrbA hypoxic transcription factor and could be triggered by nitric oxide, further implicating gaseous regulation of biofilm cellular architecture. By tracking green fluorescent protein (GFP)-Atg8 dynamics, biofilm founder cells were also observed to undergo autophagy. Most notably, biofilm cells that had undergone autophagy were triggered into further autophagy by spinning disk confocal light. Our findings indicate that fungal biofilm formation modifies the secretory and endocytic apparatus and show that biofilm cells can also undergo autophagy that is reactivated by light. The findings provide new insights into the changes occurring in fungal biofilm cell biology that potentially impact their unique characteristics, including antifungal drug resistance.
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Affiliation(s)
- Dale E Lingo
- Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210
| | - Nandini Shukla
- Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210.,The Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210
| | - Aysha H Osmani
- Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210
| | - Stephen A Osmani
- Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210
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11
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Deuterium-labeled Raman tracking of glucose accumulation and protein metabolic dynamics in Aspergillus nidulans hyphal tips. Sci Rep 2021; 11:1279. [PMID: 33446770 PMCID: PMC7809412 DOI: 10.1038/s41598-020-80270-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 12/18/2020] [Indexed: 01/29/2023] Open
Abstract
Filamentous fungi grow exclusively at their tips, where many growth-related fungal processes, such as enzyme secretion and invasion into host cells, take place. Hyphal tips are also a site of active metabolism. Understanding metabolic dynamics within the tip region is therefore important for biotechnology and medicine as well as for microbiology and ecology. However, methods that can track metabolic dynamics with sufficient spatial resolution and in a nondestructive manner are highly limited. Here we present time-lapse Raman imaging using a deuterium (D) tracer to study spatiotemporally varying metabolic activity within the hyphal tip of Aspergillus nidulans. By analyzing the carbon-deuterium (C-D) stretching Raman band with spectral deconvolution, we visualize glucose accumulation along the inner edge of the hyphal tip and synthesis of new proteins from the taken-up D-labeled glucose specifically at the central part of the apical region. Our results show that deuterium-labeled Raman imaging offers a broadly applicable platform for the study of metabolic dynamics in filamentous fungi and other relevant microorganisms in vivo.
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12
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Yin J, Hao C, Niu G, Wang W, Wang G, Xiang P, Xu JR, Zhang X. FgPal1 regulates morphogenesis and pathogenesis in Fusarium graminearum. Environ Microbiol 2020; 22:5373-5386. [PMID: 33000483 DOI: 10.1111/1462-2920.15266] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 09/29/2020] [Indexed: 12/18/2022]
Abstract
Ascospores are the primary inoculum in Fusarium graminearum, a causal agent of wheat head blight. In a previous study, FgPAL1 was found to be upregulated in the Fgama1 mutant and important for ascosporogenesis. However, the biological function of this well-conserved gene in filamentous ascomycetes is not clear. In this study, we characterized its functions in growth, differentiation and pathogenesis. The Fgpal1 mutant had severe growth defects and often displayed abnormal hyphal tips. It was defective in infectious growth in rachis tissues and spreading in wheat heads. The Fgpal1 mutant produced conidia with fewer septa and more nuclei per compartment than the wild type. In actively growing hyphal tips, FgPal1-GFP mainly localized to the subapical collar and septa. The FgPal1 and LifeAct partially co-localized at the subapical region in an interdependent manner. The Fgpal1 mutant was normal in meiosis with eight nuclei in developing asci but most asci were aborted. Taken together, our results showed that FgPal1 plays a role in maintaining polarized tip growth and coordination between nuclear division and cytokinesis, and it is also important for infectious growth and developments of ascospores by the free cell formation process.
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Affiliation(s)
- Jinrong Yin
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Chaofeng Hao
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Gang Niu
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Wei Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Guanghui Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Ping Xiang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Jin-Rong Xu
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA
| | - Xue Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
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13
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Higuchi Y, Takegawa K. Single-Molecule FISH Reveals Subcellular Localization of α-Amylase and Actin mRNAs in the Filamentous Fungus Aspergillus oryzae. Front Microbiol 2020; 11:578862. [PMID: 33072046 PMCID: PMC7536267 DOI: 10.3389/fmicb.2020.578862] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 09/01/2020] [Indexed: 11/13/2022] Open
Abstract
The machinery for mRNA localization is one of crucial molecular structures allowing cellular spatiotemporal organization of protein synthesis. Although the molecular mechanisms underlying mRNA localization have been thoroughly investigated in unicellular organisms, little is known about multicellular and multinuclear filamentous fungi. Here, we conducted single-molecule fluorescence in situ hybridization (smFISH) to first visualize the mRNA molecules of α-amylase, which are encoded by amyB, and which are thought to be abundantly secreted from the hyphal tips of the industrially important fungus Aspergillus oryzae. Consistent with previous biochemical studies, fluorescein amidite (FAM) fluorescence derived from amyB expression was observed in A. oryzae hyphae cultured in a minimal medium containing maltose instead of glucose as the sole carbon source. Moreover, after more than 1 h incubation with fresh maltose-containing medium, the fluorescence of amyB mRNAs was observed throughout the cells, suggesting α-amylase secretion potentially from each cell, instead of the hyphal tip only. Furthermore, in cultures with complete medium containing maltose, amyB mRNAs were excluded from the tip regions, where no nuclei exist. In contrast, mRNAs of actin, encoded by actA, were localized mainly to the tip, where actin proteins also preferentially reside. Collectively, our smFISH analyses revealed distinct localization patterns of α-amylase and actin mRNAs in A. oryzae hyphal cells.
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Affiliation(s)
- Yujiro Higuchi
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka, Japan
| | - Kaoru Takegawa
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka, Japan
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14
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Tolerance to alkaline ambient pH in Aspergillus nidulans depends on the activity of ENA proteins. Sci Rep 2020; 10:14325. [PMID: 32868868 PMCID: PMC7459330 DOI: 10.1038/s41598-020-71297-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 08/12/2020] [Indexed: 11/09/2022] Open
Abstract
Tolerance of microorganisms to abiotic stress is enabled by regulatory mechanisms that coordinate the expression and activity of resistance genes. Alkalinity and high salt concentrations are major environmental physicochemical stresses. Here, we analyzed the roles of sodium-extrusion family (ENA) transporters EnaA, EnaB and EnaC in the response to these stress conditions in the filamentous fungus Aspergillus nidulans. While EnaC has a minor role, EnaB is a key element for tolerance to Na+ and Li+ toxicity. Adaptation to alkaline pH requires the concerted action of EnaB with EnaA. Accordingly, expression of enaA and enaB was induced by Na+, Li+ and pH 8. These expression patterns are altered in a sltAΔ background and completely inhibited in a mutant expressing non-functional PacC protein (palH72). However, a constitutively active PacC form was not sufficient to restore maximum enaA expression. In agreement with their predicted role as membrane ATPases, EnaA localized to the plasma membrane while EnaB accumulated at structures resembling the endoplasmic reticulum. Overall, results suggest different PacC- and SltA-dependent roles for EnaB in pH and salt homeostasis, acting in coordination with EnaA at pH 8 but independently under salt stress.
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15
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Chelius C, Huso W, Reese S, Doan A, Lincoln S, Lawson K, Tran B, Purohit R, Glaros T, Srivastava R, Harris SD, Marten MR. Dynamic Transcriptomic and Phosphoproteomic Analysis During Cell Wall Stress in Aspergillus nidulans. Mol Cell Proteomics 2020; 19:1310-1329. [PMID: 32430394 PMCID: PMC8014999 DOI: 10.1074/mcp.ra119.001769] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 03/30/2020] [Indexed: 12/15/2022] Open
Abstract
The fungal cell-wall integrity signaling (CWIS) pathway regulates cellular response to environmental stress to enable wall repair and resumption of normal growth. This complex, interconnected, pathway has been only partially characterized in filamentous fungi. To better understand the dynamic cellular response to wall perturbation, a β-glucan synthase inhibitor (micafungin) was added to a growing A. nidulans shake-flask culture. From this flask, transcriptomic and phosphoproteomic data were acquired over 10 and 120 min, respectively. To differentiate statistically-significant dynamic behavior from noise, a multivariate adaptive regression splines (MARS) model was applied to both data sets. Over 1800 genes were dynamically expressed and over 700 phosphorylation sites had changing phosphorylation levels upon micafungin exposure. Twelve kinases had altered phosphorylation and phenotypic profiling of all non-essential kinase deletion mutants revealed putative connections between PrkA, Hk-8-4, and Stk19 and the CWIS pathway. Our collective data implicate actin regulation, endocytosis, and septum formation as critical cellular processes responding to activation of the CWIS pathway, and connections between CWIS and calcium, HOG, and SIN signaling pathways.
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Affiliation(s)
- Cynthia Chelius
- Department of Chemical, Biochemical, and Environmental Engineering, University of Maryland Baltimore County, Baltimore, Maryland, USA
| | - Walker Huso
- Department of Chemical, Biochemical, and Environmental Engineering, University of Maryland Baltimore County, Baltimore, Maryland, USA
| | - Samantha Reese
- Center for Plant Science Innovation and Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - Alexander Doan
- Department of Chemical, Biochemical, and Environmental Engineering, University of Maryland Baltimore County, Baltimore, Maryland, USA
| | - Stephen Lincoln
- Department of Chemical and Biomolecular Engineering, University of Connecticut, Storrs, Connecticut, USA
| | - Kelsi Lawson
- Department of Chemical, Biochemical, and Environmental Engineering, University of Maryland Baltimore County, Baltimore, Maryland, USA
| | - Bao Tran
- BioScience Mass Spectrometry Facility, The U.S. Army CCDC Chemical Biological Center, BioSciences Division, Aberdeen Proving Ground, Maryland, USA
| | - Raj Purohit
- Department of Chemical, Biochemical, and Environmental Engineering, University of Maryland Baltimore County, Baltimore, Maryland, USA
| | - Trevor Glaros
- BioSciences Division, B11 Bioenergy and Biome Sciences, Los Alamos National Laboratory, Los Alamos, New Mexico, USA
| | - Ranjan Srivastava
- Department of Chemical and Biomolecular Engineering, University of Connecticut, Storrs, Connecticut, USA
| | - Steven D Harris
- Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Mark R Marten
- Department of Chemical, Biochemical, and Environmental Engineering, University of Maryland Baltimore County, Baltimore, Maryland, USA.
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16
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Athanasopoulos A, André B, Sophianopoulou V, Gournas C. Fungal plasma membrane domains. FEMS Microbiol Rev 2020; 43:642-673. [PMID: 31504467 DOI: 10.1093/femsre/fuz022] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 08/25/2019] [Indexed: 12/11/2022] Open
Abstract
The plasma membrane (PM) performs a plethora of physiological processes, the coordination of which requires spatial and temporal organization into specialized domains of different sizes, stability, protein/lipid composition and overall architecture. Compartmentalization of the PM has been particularly well studied in the yeast Saccharomyces cerevisiae, where five non-overlapping domains have been described: The Membrane Compartments containing the arginine permease Can1 (MCC), the H+-ATPase Pma1 (MCP), the TORC2 kinase (MCT), the sterol transporters Ltc3/4 (MCL), and the cell wall stress mechanosensor Wsc1 (MCW). Additional cortical foci at the fungal PM are the sites where clathrin-dependent endocytosis occurs, the sites where the external pH sensing complex PAL/Rim localizes, and sterol-rich domains found in apically grown regions of fungal membranes. In this review, we summarize knowledge from several fungal species regarding the organization of the lateral PM segregation. We discuss the mechanisms of formation of these domains, and the mechanisms of partitioning of proteins there. Finally, we discuss the physiological roles of the best-known membrane compartments, including the regulation of membrane and cell wall homeostasis, apical growth of fungal cells and the newly emerging role of MCCs as starvation-protective membrane domains.
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Affiliation(s)
- Alexandros Athanasopoulos
- Microbial Molecular Genetics Laboratory, Institute of Biosciences and Applications, National Centre for Scientific Research 'Demokritos,' Patr. Grigoriou E & 27 Neapoleos St. 15341, Agia Paraskevi, Greece
| | - Bruno André
- Molecular Physiology of the Cell laboratory, Université Libre de Bruxelles (ULB), Institut de Biologie et de Médecine Moléculaires, rue des Pr Jeener et Brachet 12, 6041, Gosselies, Belgium
| | - Vicky Sophianopoulou
- Microbial Molecular Genetics Laboratory, Institute of Biosciences and Applications, National Centre for Scientific Research 'Demokritos,' Patr. Grigoriou E & 27 Neapoleos St. 15341, Agia Paraskevi, Greece
| | - Christos Gournas
- Microbial Molecular Genetics Laboratory, Institute of Biosciences and Applications, National Centre for Scientific Research 'Demokritos,' Patr. Grigoriou E & 27 Neapoleos St. 15341, Agia Paraskevi, Greece
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17
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Commer B, Schultzhaus Z, Shaw BD. Localization of NPFxD motif-containing proteins in Aspergillus nidulans. Fungal Genet Biol 2020; 141:103412. [PMID: 32445863 DOI: 10.1016/j.fgb.2020.103412] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 05/04/2020] [Accepted: 05/10/2020] [Indexed: 12/28/2022]
Abstract
During growth, filamentous fungi produce polarized cells called hyphae. It is generally presumed that polarization of hyphae is dependent upon secretion through the Spitzenkörper, as well as a mechanism called apical recycling, which maintains a balance between the tightly coupled processes of endocytosis and exocytosis. Endocytosis predominates in an annular domain called the sub-apical endocytic collar, which is located in the region of plasma membrane 1-5 μm distal to the Spitzenkörper. It has previously been proposed that one function of the sub-apical endocytic collar is to maintain the apical localization of polarization proteins. These proteins mark areas of polarization at the apices of hyphae. However, as hyphae grow, these proteins are displaced along the membrane and some must then be removed at the sub-apical endocytic collar in order to maintain the hyphoid shape. While endocytosis is fairly well characterized in yeast, comparatively little is known about the process in filamentous fungi. Here, a bioinformatics approach was utilized to identify 39 Aspergillus nidulans proteins that are predicted to be cargo of endocytosis based on the presence of an NPFxD peptide motif. This motif is a necessary endocytic signal sequence first established in Saccharomyces cerevisiae, where it marks proteins for endocytosis through an interaction with the adapter protein Sla1p. It is hypothesized that some proteins that contain this NPFxD peptide sequence in A. nidulans will be potential targets for endocytosis, and therefore will localize either to the endocytic collar or to more proximal polarized regions of the cell, e.g. the apical dome or the Spitzenkörper. To test this, a subset of the motif-containing proteins in A. nidulans was tagged with GFP and the dynamic localization was evaluated. The documented localization patterns support the hypothesis that the motif marks proteins for localization to the polarized cell apex in growing hyphae.
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Affiliation(s)
- Blake Commer
- Department of Plant Pathology and Microbiology, Texas A&M University, 2132 TAMU, College Station, TX 77843, USA.
| | - Zachary Schultzhaus
- Department of Plant Pathology and Microbiology, Texas A&M University, 2132 TAMU, College Station, TX 77843, USA.
| | - Brian D Shaw
- Department of Plant Pathology and Microbiology, Texas A&M University, 2132 TAMU, College Station, TX 77843, USA.
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18
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Han X, Chen L, Li W, Zhang L, Zhang L, Zou S, Liang Y, Yu J, Dong H. Endocytic FgEde1 regulates virulence and autophagy in Fusarium graminearum. Fungal Genet Biol 2020; 141:103400. [PMID: 32387406 DOI: 10.1016/j.fgb.2020.103400] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 03/07/2020] [Accepted: 05/01/2020] [Indexed: 12/17/2022]
Abstract
Endocytosis plays critical roles in cellular processes, including nutrient uptake and signal transduction. Ede1 is an endocytic scaffolding protein that contributes to endocytic site initiation and maturation in yeast. However, the functions of Ede1 in phytopathogenic fungi are not known. Here, we identified functions of FgEde1 (FGSG_05182) in Fusarium graminearum. Deletion of FgEde1 resulted in defects in hyphal growth, conidiation and ascospore development. The FgEde1 deletion mutant showed reduced deoxynivalenol (DON) production and virulence in wheat. Furthermore, the FgEde1 deletion mutant also exhibited increased resistance to osmotic and oxidative stress as well as cell-wall perturbing agents. Importantly, deletion of FgEde1 increased the severity of autophagy in hyphae. Taken together, these results reveal that FgEde1 is involved in hyphal growth, asexual and sexual reproduction, virulence, stress responses, and autophagy in F. graminearum.
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Affiliation(s)
- Xuelian Han
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Taian 271018, China
| | - Lei Chen
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Taian 271018, China
| | - Weidong Li
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Taian 271018, China
| | - Li Zhang
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Taian 271018, China
| | - Liyuan Zhang
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Taian 271018, China
| | - Shenshen Zou
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Taian 271018, China
| | - Yuancun Liang
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Taian 271018, China.
| | - Jinfeng Yu
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Taian 271018, China
| | - Hansong Dong
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Taian 271018, China
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19
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Abstract
Filamentous fungi grow by adding cell wall and membrane exclusively at the apex of tubular structures called hyphae. Growth was previously believed to occur only through exocytosis at the Spitzenkörper, an organised body of secretory macro- and microvesicles found only in growing hyphae. More recent work has indicated that an area deemed the sub-apical collar is enriched for endocytosis and is also required for hyphal growth. It is now generally believed that polarity of filamentous fungi is achieved through the balancing of the processes of endocytosis and exocytosis at these two areas. This review is an update on the current progress and understanding surrounding the occurrence of endocytosis and its spatial regulation as they pertain to growth and pathogenicity in filamentous fungi.
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Affiliation(s)
- Blake Commer
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX, USA
| | - Brian D Shaw
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX, USA
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20
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Actin Is Required for Cellular Development and Virulence of Botrytis cinerea via the Mediation of Secretory Proteins. mSystems 2020; 5:5/1/e00732-19. [PMID: 32098836 PMCID: PMC7043344 DOI: 10.1128/msystems.00732-19] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The cytoskeleton is an important network that exists in cells of all domains of life. In eukaryotic cells, actin is a vital component of the cytoskeleton. Here, we report that BcactA, an actin protein in B. cinerea, can affect the growth, sporulation, and virulence of B. cinerea. Furthermore, iTRAQ-based proteomic analysis showed that BcactA affects the abundance of 40 extracellular proteins, including 11 down-accumulated CWDEs. Among them, two CWDEs, cellobiohydrolase (BcCBH) and β-endoglucanase (BcEG), contributed to the virulence of B. cinerea, indicating that bcactA plays a crucial role in regulating extracellular virulence factors. These findings unveil previously unknown functions of BcactA in mediating growth, sporulation, and virulence of B. cinerea. Actin is a vital component of the cytoskeleton of living cells and is involved in several complex processes. However, its functions in plant-pathogenic fungi are largely unknown. In this paper, we found that deletion of the Botrytis cinerea actin gene bcactA reduced growth and sporulation of B. cinerea and lowered virulence. Based on iTRAQ (isobaric tags for relative and absolute quantification)-based proteomic analysis, we compared changes of the secretome in ΔbcactA and wild-type strains. A total of 40 proteins exhibited significant differences in abundance in ΔbcactA mutants compared with the wild type. These proteins included 11 down-accumulated cell wall-degrading enzymes (CWDEs). Among them, two CWDEs, cellobiohydrolase (BcCBH) and β-endoglucanase (BcEG), were found to contribute to the virulence of B. cinerea, indicating that bcactA plays a crucial role in regulating the secretion of extracellular virulence factors. These findings unveil previously unknown functions of BcactA to mediate the virulence of B. cinerea and provide new mechanistic insights into the role of BcactA in the complex pathogenesis of B. cinerea. IMPORTANCE The cytoskeleton is an important network that exists in cells of all domains of life. In eukaryotic cells, actin is a vital component of the cytoskeleton. Here, we report that BcactA, an actin protein in B. cinerea, can affect the growth, sporulation, and virulence of B. cinerea. Furthermore, iTRAQ-based proteomic analysis showed that BcactA affects the abundance of 40 extracellular proteins, including 11 down-accumulated CWDEs. Among them, two CWDEs, cellobiohydrolase (BcCBH) and β-endoglucanase (BcEG), contributed to the virulence of B. cinerea, indicating that bcactA plays a crucial role in regulating extracellular virulence factors. These findings unveil previously unknown functions of BcactA in mediating growth, sporulation, and virulence of B. cinerea.
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21
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Mamun MAA, Katayama T, Cao W, Nakamura S, Maruyama JI. A novel Pezizomycotina-specific protein with gelsolin domains regulates contractile actin ring assembly and constriction in perforated septum formation. Mol Microbiol 2020; 113:964-982. [PMID: 31965663 DOI: 10.1111/mmi.14463] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 01/13/2020] [Accepted: 01/13/2020] [Indexed: 12/29/2022]
Abstract
Septum formation in fungi is equivalent to cytokinesis. It differs mechanistically in filamentous ascomycetes (Pezizomycotina) from that of ascomycete yeasts by the retention of a central septal pore in the former group. However, septum formation in both groups is accomplished by contractile actin ring (CAR) assembly and constriction. The specific components regulating septal pore organization during septum formation are poorly understood. In this study, a novel Pezizomycotina-specific actin regulatory protein GlpA containing gelsolin domains was identified using bioinformatics. A glpA deletion mutant exhibited increased distances between septa, abnormal septum morphology and defective regulation of septal pore closure. In glpA deletion mutant hyphae, overaccumulation of actin filament (F-actin) was observed, and the CAR was abnormal with improper assembly and failure in constriction. In wild-type cells, GlpA was found at the septum formation site similarly to the CAR. The N-terminal 329 residues of GlpA are required for its localization to the septum formation site and essential for proper septum formation, while its C-terminal gelsolin domains are required for the regular CAR dynamics during septum formation. Finally, in this study we elucidated a novel Pezizomycotina-specific actin modulating component, which participates in septum formation by regulating the CAR dynamics.
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Affiliation(s)
| | - Takuya Katayama
- Department of Biotechnology, The University of Tokyo, Tokyo, Japan.,Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Tokyo, Japan
| | - Wei Cao
- Faculty of Information Networking for Innovation and Design, Department of Information Networking for Innovation and Design, Toyo University, Tokyo, Japan
| | - Shugo Nakamura
- Faculty of Information Networking for Innovation and Design, Department of Information Networking for Innovation and Design, Toyo University, Tokyo, Japan
| | - Jun-Ichi Maruyama
- Department of Biotechnology, The University of Tokyo, Tokyo, Japan.,Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Tokyo, Japan
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22
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External signal-mediated polarized growth in fungi. Curr Opin Cell Biol 2019; 62:150-158. [PMID: 31875532 DOI: 10.1016/j.ceb.2019.11.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 10/28/2019] [Accepted: 11/04/2019] [Indexed: 12/13/2022]
Abstract
As the majority of fungi are nonmotile, polarized growth in response to an external signal enables them to search for nutrients and mating partners, and hence is crucial for survival and proliferation. Although the mechanisms underlying polarization in response to external signals has commonalities with polarization during mitotic division, during budding, and fission growth, the importance of diverse feedback loops regulating external signal-mediated polarized growth is likely to be distinct and uniquely adapted to a dynamic environment. Here, we highlight recent advances in our understanding of the mechanisms that are crucial for polarity in response to external signals in fungi, with particular focus on the roles of membrane traffic, small GTPases, and lipids, as well as the interplay between cell shape and cell growth.
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23
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Zhang J, Yun Y, Lou Y, Abubakar YS, Guo P, Wang S, Li C, Feng Y, Adnan M, Zhou J, Lu G, Zheng W. FgAP‐2 complex is essential for pathogenicity and polarised growth and regulates the apical localisation of membrane lipid flippases in
Fusarium graminearum. Cell Microbiol 2019; 21:e13041. [DOI: 10.1111/cmi.13041] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 04/11/2019] [Accepted: 05/12/2019] [Indexed: 12/20/2022]
Affiliation(s)
- Jing Zhang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant ProtectionFujian Agriculture and Forestry University Fuzhou China
| | - Yingzi Yun
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant ProtectionFujian Agriculture and Forestry University Fuzhou China
| | - Yi Lou
- Fujian Province Key Laboratory of Pathogenic Fungi and Mycotoxins, College of Life SciencesFujian Agriculture and Forestry University Fuzhou China
| | | | - Pusheng Guo
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant ProtectionFujian Agriculture and Forestry University Fuzhou China
| | - Shumin Wang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant ProtectionFujian Agriculture and Forestry University Fuzhou China
| | - Chunling Li
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant ProtectionFujian Agriculture and Forestry University Fuzhou China
| | - Yuan Feng
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant ProtectionFujian Agriculture and Forestry University Fuzhou China
| | - Muhammad Adnan
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant ProtectionFujian Agriculture and Forestry University Fuzhou China
| | - Jie Zhou
- Fujian Province Key Laboratory of Pathogenic Fungi and Mycotoxins, College of Life SciencesFujian Agriculture and Forestry University Fuzhou China
| | - Guo‐dong Lu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant ProtectionFujian Agriculture and Forestry University Fuzhou China
| | - Wenhui Zheng
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant ProtectionFujian Agriculture and Forestry University Fuzhou China
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24
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Verdín J, Sánchez-León E, Rico-Ramírez AM, Martínez-Núñez L, Fajardo-Somera RA, Riquelme M. Off the wall: The rhyme and reason of Neurospora crassa hyphal morphogenesis. ACTA ACUST UNITED AC 2019; 5:100020. [PMID: 32743136 PMCID: PMC7389182 DOI: 10.1016/j.tcsw.2019.100020] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 02/07/2019] [Accepted: 02/10/2019] [Indexed: 12/11/2022]
Abstract
Chitin and β-1,3-glucan synthases are transported separately in chitosomes and macrovesicles. Chitin synthases occupy the core of the SPK; β-1,3-glucan synthases the outer layer. CHS-4 arrival to the SPK and septa is CSE-7 dependent. Rabs YPT-1 and YPT-31 localization at the SPK mimics that of chitosomes and macrovesicles. The exocyst acts as a tether between the SPK outer layer vesicles and the apical PM.
The fungal cell wall building processes are the ultimate determinants of hyphal shape. In Neurospora crassa the main cell wall components, β-1,3-glucan and chitin, are synthesized by enzymes conveyed by specialized vesicles to the hyphal tip. These vesicles follow different secretory routes, which are delicately coordinated by cargo-specific Rab GTPases until their accumulation at the Spitzenkörper. From there, the exocyst mediates the docking of secretory vesicles to the plasma membrane, where they ultimately get fused. Although significant progress has been done on the cellular mechanisms that carry cell wall synthesizing enzymes from the endoplasmic reticulum to hyphal tips, a lot of information is still missing. Here, the current knowledge on N. crassa cell wall composition and biosynthesis is presented with an emphasis on the underlying molecular and cellular secretory processes.
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Key Words
- BGT, β-1,3-glucan transferases
- CHS, chitin synthase
- CLSM, confocal laser scanning microscopy
- CWI, cell wall integrity
- CWP, cell wall proteins
- Cell wall
- ER, endoplasmic reticulum
- FRAP, fluorescence recovery after photobleaching
- GEF, guanine nucleotide exchange factor
- GFP, green fluorescent protein
- GH, glycosyl hydrolases
- GPI, glycosylphosphatidylinositol
- GSC, β-1,3-glucan synthase complex
- MMD, myosin-like motor domain
- MS, mass spectrometry
- MT, microtubule
- NEC, network of elongated cisternae
- PM, plasma membrane
- SPK, Spitzenkörper
- Spitzenkörper
- TIRFM, total internal reflection fluorescence microscopy
- TM, transmembrane
- Tip growth
- Vesicles
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Affiliation(s)
- Jorge Verdín
- Industrial Biotechnology, CIATEJ-Jalisco State Scientific Research and Technology Assistance Center, Mexico National Council for Science and Technology, Zapopan, Jalisco, Mexico
| | - Eddy Sánchez-León
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
| | - Adriana M Rico-Ramírez
- Department of Microbiology, Centro de Investigación Científica y de Educación Superior de Ensenada, CICESE Ensenada, Baja California, Mexico
| | - Leonora Martínez-Núñez
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Rosa A Fajardo-Somera
- Karlsruhe Institute of Technology (KIT) South Campus, Institute for Applied Biosciences, Department of Microbiology, Karlsruhe, Germany
| | - Meritxell Riquelme
- Department of Microbiology, Centro de Investigación Científica y de Educación Superior de Ensenada, CICESE Ensenada, Baja California, Mexico
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25
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Regulation of Candida albicans Hyphal Morphogenesis by Endogenous Signals. J Fungi (Basel) 2019; 5:jof5010021. [PMID: 30823468 PMCID: PMC6463138 DOI: 10.3390/jof5010021] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 02/25/2019] [Accepted: 02/26/2019] [Indexed: 12/15/2022] Open
Abstract
Candida albicans is a human commensal fungus that is able to assume several morphologies, including yeast, hyphal, and pseudohyphal. Under a range of conditions, C. albicans performs a regulated switch to the filamentous morphology, characterized by the emergence of a germ tube from the yeast cell, followed by a mold-like growth of branching hyphae. This transition from yeast to hyphal growth has attracted particular attention, as it has been linked to the virulence of C. albicans as an opportunistic human pathogen. Signal transduction pathways that mediate the induction of the hyphal transcription program upon the imposition of external stimuli have been extensively investigated. However, the hyphal morphogenesis transcription program can also be induced by internal cellular signals, such as inhibition of cell cycle progression, and conversely, the inhibition of hyphal extension can repress hyphal-specific gene expression, suggesting that endogenous cellular signals are able to modulate hyphal gene expression as well. Here we review recent developments in the regulation of the hyphal morphogenesis of C. albicans, with emphasis on endogenous morphogenetic signals.
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Aspergillus nidulans in the post-genomic era: a top-model filamentous fungus for the study of signaling and homeostasis mechanisms. Int Microbiol 2019; 23:5-22. [DOI: 10.1007/s10123-019-00064-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 01/30/2019] [Accepted: 02/04/2019] [Indexed: 02/07/2023]
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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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The actin capping protein in Aspergillus nidulans enhances dynein function without significantly affecting Arp1 filament assembly. Sci Rep 2018; 8:11419. [PMID: 30061726 PMCID: PMC6065395 DOI: 10.1038/s41598-018-29818-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 07/18/2018] [Indexed: 11/08/2022] Open
Abstract
The minus-end-directed microtubule motor cytoplasmic dynein requires the dynactin complex for in vivo functions. The backbone of the vertebrate dynactin complex is the Arp1 (actin-related protein 1) mini-filament whose barbed end binds to the heterodimeric actin capping protein. However, it is unclear whether the capping protein is a dynactin component in lower eukaryotic organisms, especially because it does not appear to be a component of the budding yeast dynactin complex. Here our biochemical data show that the capping protein is a component of the dynactin complex in the filamentous fungus Aspergillus nidulans. Moreover, deletion of the gene encoding capping protein alpha (capA) results in a defect in both nuclear distribution and early-endosome transport, two dynein-mediated processes. However, the defect in either process is less severe than that exhibited by a dynein heavy chain mutant or the ∆p25 mutant of dynactin. In addition, loss of capping protein does not significantly affect the assembly of the dynactin Arp1 filament or the formation of the dynein-dynactin-∆C-HookA (Hook in A. nidulans) complex. These results suggest that fungal capping protein is not important for Arp1 filament assembly but its presence is required for enhancing dynein function in vivo.
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Bartnicki-Garcia S, Garduño-Rosales M, Delgado-Alvarez DL, Mouriño-Pérez RR. Experimental measurement of endocytosis in fungal hyphae. Fungal Genet Biol 2018; 118:32-36. [PMID: 30017938 DOI: 10.1016/j.fgb.2018.07.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 06/27/2018] [Accepted: 07/01/2018] [Indexed: 11/15/2022]
Abstract
The present study examines the notion that polarized exocytosis in the tips of growing hyphae creates an excess of plasma membrane and thus the need for its removal by endocytosis. To measure endocytosis experimentally, we developed a photobleaching (FRAP) procedure to count endocytic events in hyphae of Neurospora crassa carrying a fluorescent tag on the actin-binding protein fimbrin (FIM-1-GFP). Given 40 nm as the average diameter of endocytic vesicles, we calculated that about 12.5% of the plasma membrane discharged in the apex becomes endocytosed in the subapex. According to our calculations, the GFP-tagged hyphae of N. crassa, measured under the constrained conditions of confocal microscopic examination, needed about 8800 vesicles/min to extend their plasma membrane or about 9800/min, if we include predicted demands for cell wall growth and extracellular secretion. Our findings support the notion that exocytosis and endocytosis operate in tandem with the latter serving as a compensatory process to remove any excess of plasma membrane generated by the intense exocytosis in the hyphal tips. Presumably, this tandem arrangement evolved to support the hallmark features of fungi namely rapid cell extension and abundant secretion of hydrolytic enzymes.
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Affiliation(s)
- Salomon Bartnicki-Garcia
- Departamento de Microbiología, CICESE (Centro de Investigación Científica y Educación Superior de Ensenada), Mexico
| | - Marisela Garduño-Rosales
- Departamento de Microbiología, CICESE (Centro de Investigación Científica y Educación Superior de Ensenada), Mexico
| | - Diego Luis Delgado-Alvarez
- Departamento de Microbiología, CICESE (Centro de Investigación Científica y Educación Superior de Ensenada), Mexico
| | - Rosa Reyna Mouriño-Pérez
- Departamento de Microbiología, CICESE (Centro de Investigación Científica y Educación Superior de Ensenada), Mexico.
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Secretory Vesicle Polar Sorting, Endosome Recycling and Cytoskeleton Organization Require the AP-1 Complex in Aspergillus nidulans. Genetics 2018; 209:1121-1138. [PMID: 29925567 DOI: 10.1534/genetics.118.301240] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Accepted: 06/19/2018] [Indexed: 11/18/2022] Open
Abstract
The AP-1 complex is essential for membrane protein traffic via its role in the pinching-off and sorting of secretory vesicles (SVs) from the trans-Golgi and/or endosomes. While its essentiality is undisputed in metazoa, its role in simpler eukaryotes seems less clear. Here, we dissect the role of AP-1 in the filamentous fungus Aspergillus nidulans and show that it is absolutely essential for growth due to its role in clathrin-dependent maintenance of polar traffic of specific membrane cargoes toward the apex of growing hyphae. We provide evidence that AP-1 is involved in both anterograde sorting of RabERab11-labeled SVs and RabA/BRab5-dependent endosome recycling. Additionally, AP-1 is shown to be critical for microtubule and septin organization, further rationalizing its essentiality in cells that face the challenge of cytoskeleton-dependent polarized cargo traffic. This work also opens a novel issue on how nonpolar cargoes, such as transporters, are sorted to the eukaryotic plasma membrane.
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Riquelme M, Aguirre J, Bartnicki-García S, Braus GH, Feldbrügge M, Fleig U, Hansberg W, Herrera-Estrella A, Kämper J, Kück U, Mouriño-Pérez RR, Takeshita N, Fischer R. Fungal Morphogenesis, from the Polarized Growth of Hyphae to Complex Reproduction and Infection Structures. Microbiol Mol Biol Rev 2018; 82:e00068-17. [PMID: 29643171 PMCID: PMC5968459 DOI: 10.1128/mmbr.00068-17] [Citation(s) in RCA: 183] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Filamentous fungi constitute a large group of eukaryotic microorganisms that grow by forming simple tube-like hyphae that are capable of differentiating into more-complex morphological structures and distinct cell types. Hyphae form filamentous networks by extending at their tips while branching in subapical regions. Rapid tip elongation requires massive membrane insertion and extension of the rigid chitin-containing cell wall. This process is sustained by a continuous flow of secretory vesicles that depends on the coordinated action of the microtubule and actin cytoskeletons and the corresponding motors and associated proteins. Vesicles transport cell wall-synthesizing enzymes and accumulate in a special structure, the Spitzenkörper, before traveling further and fusing with the tip membrane. The place of vesicle fusion and growth direction are enabled and defined by the position of the Spitzenkörper, the so-called cell end markers, and other proteins involved in the exocytic process. Also important for tip extension is membrane recycling by endocytosis via early endosomes, which function as multipurpose transport vehicles for mRNA, septins, ribosomes, and peroxisomes. Cell integrity, hyphal branching, and morphogenesis are all processes that are largely dependent on vesicle and cytoskeleton dynamics. When hyphae differentiate structures for asexual or sexual reproduction or to mediate interspecies interactions, the hyphal basic cellular machinery may be reprogrammed through the synthesis of new proteins and/or the modification of protein activity. Although some transcriptional networks involved in such reprogramming of hyphae are well studied in several model filamentous fungi, clear connections between these networks and known determinants of hyphal morphogenesis are yet to be established.
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Affiliation(s)
- Meritxell Riquelme
- Department of Microbiology, Centro de Investigación Científica y de Educación Superior de Ensenada, Ensenada, Baja California, Mexico
| | - Jesús Aguirre
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de Mexico, Mexico City, Mexico
| | - Salomon Bartnicki-García
- Department of Microbiology, Centro de Investigación Científica y de Educación Superior de Ensenada, Ensenada, Baja California, Mexico
| | - Gerhard H Braus
- Department of Molecular Microbiology and Genetics and Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, Goettingen, Germany
| | - Michael Feldbrügge
- Institute for Microbiology, Heinrich Heine University Düsseldorf, Cluster of Excellence on Plant Sciences, Düsseldorf, Germany
| | - Ursula Fleig
- Institute for Functional Genomics of Microorganisms, Heinrich Heine University Düsseldorf, Cluster of Excellence on Plant Sciences, Düsseldorf, Germany
| | - Wilhelm Hansberg
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de Mexico, Mexico City, Mexico
| | - Alfredo Herrera-Estrella
- Laboratorio Nacional de Genómica para la Biodiversidad, Centro de Investigación y de Estudios Avanzados del IPN, Irapuato, Mexico
| | - Jörg Kämper
- Karlsruhe Institute of Technology-South Campus, Institute for Applied Biosciences, Karlsruhe, Germany
| | - Ulrich Kück
- Ruhr University Bochum, Lehrstuhl für Allgemeine und Molekulare Botanik, Bochum, Germany
| | - Rosa R Mouriño-Pérez
- Department of Microbiology, Centro de Investigación Científica y de Educación Superior de Ensenada, Ensenada, Baja California, Mexico
| | - Norio Takeshita
- University of Tsukuba, Faculty of Life and Environmental Sciences, Tsukuba, Japan
| | - Reinhard Fischer
- Karlsruhe Institute of Technology-South Campus, Institute for Applied Biosciences, Karlsruhe, Germany
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Hernández-González M, Bravo-Plaza I, Pinar M, de los Ríos V, Arst HN, Peñalva MA. Endocytic recycling via the TGN underlies the polarized hyphal mode of life. PLoS Genet 2018; 14:e1007291. [PMID: 29608571 PMCID: PMC5880334 DOI: 10.1371/journal.pgen.1007291] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 03/06/2018] [Indexed: 12/13/2022] Open
Abstract
Intracellular traffic in Aspergillus nidulans hyphae must cope with the challenges that the high rates of apical extension (1μm/min) and the long intracellular distances (>100 μm) impose. Understanding the ways in which the hyphal tip cell coordinates traffic to meet these challenges is of basic importance, but is also of considerable applied interest, as fungal invasiveness of animals and plants depends critically upon maintaining these high rates of growth. Rapid apical extension requires localization of cell-wall-modifying enzymes to hyphal tips. By combining genetic blocks in different trafficking steps with multidimensional epifluorescence microscopy and quantitative image analyses we demonstrate that polarization of the essential chitin-synthase ChsB occurs by indirect endocytic recycling, involving delivery/exocytosis to apices followed by internalization by the sub-apical endocytic collar of actin patches and subsequent trafficking to TGN cisternae, where it accumulates for ~1 min before being re-delivered to the apex by a RAB11/TRAPPII-dependent pathway. Accordingly, ChsB is stranded at the TGN by Sec7 inactivation but re-polarizes to the apical dome if the block is bypassed by a mutation in geaAgea1 that restores growth in the absence of Sec7. That polarization is independent of RAB5, that ChsB predominates at apex-proximal cisternae, and that upon dynein impairment ChsB is stalled at the tips in an aggregated endosome indicate that endocytosed ChsB traffics to the TGN via sorting endosomes functionally located upstream of the RAB5 domain and that this step requires dynein-mediated basipetal transport. It also requires RAB6 and its effector GARP (Vps51/Vps52/Vps53/Vps54), whose composition we determined by MS/MS following affinity chromatography purification. Ablation of any GARP component diverts ChsB to vacuoles and impairs growth and morphology markedly, emphasizing the important physiological role played by this pathway that, we propose, is central to the hyphal mode of growth. Filamentous fungi form long tubular cells, called hyphae, which grow rapidly by apical extension, enabling these sessile organisms to explore substrates and facilitating tissue invasion in the case of pathogenic species. Because the shape of the hyphae is determined by an external cell wall, hyphal growth requires that cell-wall sculpting enzymes polarize to the tips. Endocytosis is essential for hyphal growth, and it was suspected that this results from its participation in a recycling pathway that takes up cell-wall enzymes from the plasma membrane and re-delivers them to the apex. Here we track the trafficking of a chitin synthase (a cell-wall modifying enzyme) to demonstrate that it is polarized by endocytic recycling. This chitin synthase is delivered by exocytosis to the apex, but diffuses away until being captured by a subapical collar of actin patches (sites of endocytosis) from where it reaches a sorting endosome before undergoing transport to the nearest trans-Golgi cisternae and incorporating into secretory vesicles that re-deliver the enzyme to the apex. Because impairing transit across this pathway compromises apical extension markedly and results in severe morphological defects, the pathway could be manipulated to prevent fungal pathogenicity of plants and humans, an enormous burden on human welfare.
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Affiliation(s)
- Miguel Hernández-González
- Department of Cellular and Molecular Biology and Intradepartmental WhiteBiotech Unit, Centro de Investigaciones Biológicas del Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu, Madrid, Spain
| | - Ignacio Bravo-Plaza
- Department of Cellular and Molecular Biology and Intradepartmental WhiteBiotech Unit, Centro de Investigaciones Biológicas del Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu, Madrid, Spain
| | - Mario Pinar
- Department of Cellular and Molecular Biology and Intradepartmental WhiteBiotech Unit, Centro de Investigaciones Biológicas del Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu, Madrid, Spain
| | - Vivian de los Ríos
- Proteomics Facility, Centro de Investigaciones Biológicas del Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu, Madrid, Spain
| | - Herbert N. Arst
- Section of Microbiology, Imperial College London, Flowers Building, Armstrong Road, London, United Kingdom
| | - Miguel A. Peñalva
- Department of Cellular and Molecular Biology and Intradepartmental WhiteBiotech Unit, Centro de Investigaciones Biológicas del Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu, Madrid, Spain
- * E-mail:
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Zhou L, Evangelinos M, Wernet V, Eckert AF, Ishitsuka Y, Fischer R, Nienhaus GU, Takeshita N. Superresolution and pulse-chase imaging reveal the role of vesicle transport in polar growth of fungal cells. SCIENCE ADVANCES 2018; 4:e1701798. [PMID: 29387789 PMCID: PMC5787382 DOI: 10.1126/sciadv.1701798] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Accepted: 12/27/2017] [Indexed: 06/07/2023]
Abstract
Polarized growth of filamentous fungi requires continuous transport of biomolecules to the hyphal tip. To this end, construction materials are packaged in vesicles and transported by motor proteins along microtubules and actin filaments. We have studied these processes with quantitative superresolution localization microscopy of live Aspergillus nidulans cells expressing the photoconvertible protein mEosFPthermo fused to the chitin synthase ChsB. ChsB is mainly located at the Spitzenkörper near the hyphal tip and produces chitin, a key component of the cell wall. We have visualized the pulsatory dynamics of the Spitzenkörper, reflecting vesicle accumulation before exocytosis and their subsequent fusion with the apical plasma membrane. Furthermore, high-speed pulse-chase imaging after photoconversion of mEosFPthermo in a tightly focused spot revealed that ChsB is transported with two different speeds from the cell body to the hyphal tip and vice versa. Comparative analysis using motor protein deletion mutants allowed us to assign the fast movements (7 to 10 μm s-1) to transport of secretory vesicles by kinesin-1, and the slower ones (2 to 7 μm s-1) to transport by kinesin-3 on early endosomes. Our results show how motor proteins ensure the supply of vesicles to the hyphal tip, where temporally regulated exocytosis results in stepwise tip extension.
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Affiliation(s)
- Lu Zhou
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
- Institute of Nanotechnology, KIT, Karlsruhe, Germany
| | - Minoas Evangelinos
- Department of Microbiology, Institute for Applied Biosciences, KIT, Karlsruhe, Germany
- Faculty of Biology, University of Athens, Athens, Greece
- Institut de Biologie et de Médecine Moléculaires, Université Libre de Bruxelles, Gosselies, Belgium
| | - Valentin Wernet
- Department of Microbiology, Institute for Applied Biosciences, KIT, Karlsruhe, Germany
| | - Antonia F. Eckert
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Yuji Ishitsuka
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Reinhard Fischer
- Department of Microbiology, Institute for Applied Biosciences, KIT, Karlsruhe, Germany
| | - G. Ulrich Nienhaus
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
- Institute of Nanotechnology, KIT, Karlsruhe, Germany
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Institute of Toxicology and Genetics, KIT, Eggenstein-Leopoldshafen, Germany
| | - Norio Takeshita
- Department of Microbiology, Institute for Applied Biosciences, KIT, Karlsruhe, Germany
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
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Etxebeste O, Espeso EA. Neurons show the path: tip-to-nucleus communication in filamentous fungal development and pathogenesis. FEMS Microbiol Rev 2017; 40:610-24. [PMID: 27587717 DOI: 10.1093/femsre/fuw021] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/17/2016] [Indexed: 01/11/2023] Open
Abstract
Multiple fungal species penetrate substrates and accomplish host invasion through the fast, permanent and unidirectional extension of filamentous cells known as hyphae. Polar growth of hyphae results, however, in a significant increase in the distance between the polarity site, which also receives the earliest information about ambient conditions, and nuclei, where adaptive responses are executed. Recent studies demonstrate that these long distances are overcome by signal transduction pathways which convey sensory information from the polarity site to nuclei, controlling development and pathogenesis. The present review compares the striking connections of the mechanisms for long-distance communication in hyphae with those from neurons, and discusses the importance of their study in order to understand invasion and dissemination processes of filamentous fungi, and design strategies for developmental control in the future.
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Affiliation(s)
- Oier Etxebeste
- Biochemistry II laboratory, Department of Applied Chemistry, Faculty of Chemistry, University of the Basque Country (UPV/EHU), 20018 San Sebastian, Spain
| | - Eduardo A Espeso
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas (CSIC), Ramiro de Maeztu 9, 28040 Madrid, Spain
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Abstract
Filamentous fungi are a large and ancient clade of microorganisms that occupy a broad range of ecological niches. The success of filamentous fungi is largely due to their elongate hypha, a chain of cells, separated from each other by septa. Hyphae grow by polarized exocytosis at the apex, which allows the fungus to overcome long distances and invade many substrates, including soils and host tissues. Hyphal tip growth is initiated by establishment of a growth site and the subsequent maintenance of the growth axis, with transport of growth supplies, including membranes and proteins, delivered by motors along the cytoskeleton to the hyphal apex. Among the enzymes delivered are cell wall synthases that are exocytosed for local synthesis of the extracellular cell wall. Exocytosis is opposed by endocytic uptake of soluble and membrane-bound material into the cell. The first intracellular compartment in the endocytic pathway is the early endosomes, which emerge to perform essential additional functions as spatial organizers of the hyphal cell. Individual compartments within septated hyphae can communicate with each other via septal pores, which allow passage of cytoplasm or organelles to help differentiation within the mycelium. This article introduces the reader to more detailed aspects of hyphal growth in fungi.
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Abstract
The eukaryotic actin cytoskeleton is a highly dynamic framework that is involved in many biological processes, such as cell growth, division, morphology, and motility. G-actin polymerizes into microfilaments that associate into bundles, patches, and networks, which, in turn, organize into higher order structures that are fundamental for the course of important physiological events. Actin rings are an example for such higher order actin entities, but this term represents an actually diverse set of subcellular structures that are involved in various processes. This review especially sheds light on a crucial type of non-constricting ring-like actin networks, and categorizes them under the term 'actin fringe'. These 'actin fringes' are visualized as highly dynamic and yet steady structures in the tip of various polarized growing cells. The present comprehensive overview compares the actin fringe characteristics of rapidly elongating pollen tubes with several related actin arrays in other cell types of diverse species. The current state of knowledge about various actin fringe functions is summarized, and the key role of this structure in the polar growth process is discussed.
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Affiliation(s)
- Octavian O H Stephan
- Department of Biology, Friedrich-Alexander University of Erlangen-Nuremberg, Erlangen, Bavaria 91058, Germany
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Zhang B, Hua Y, Wang J, Huo Y, Shimono M, Day B, Ma Q. TaADF4, an actin-depolymerizing factor from wheat, is required for resistance to the stripe rust pathogen Puccinia striiformis f. sp. tritici. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 89:1210-1224. [PMID: 27995685 DOI: 10.1111/tpj.13459] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 12/12/2016] [Accepted: 12/14/2016] [Indexed: 05/21/2023]
Abstract
Actin filament assembly in plants is a dynamic process, requiring the activity of more than 75 actin-binding proteins. Central to the regulation of filament assembly and stability is the activity of a conserved family of actin-depolymerizing factors (ADFs), whose primarily function is to regulate the severing and depolymerization of actin filaments. In recent years, the activity of ADF proteins has been linked to a variety of cellular processes, including those associated with response to stress. Herein, a wheat ADF gene, TaADF4, was identified and characterized. TaADF4 encodes a 139-amino-acid protein containing five F-actin-binding sites and two G-actin-binding sites, and interacts with wheat (Triticum aestivum) Actin1 (TaACT1), in planta. Following treatment of wheat, separately, with jasmonic acid, abscisic acid or with the avirulent race, CYR23, of the stripe rust pathogen Puccinia striiformis f. sp. tritici, we observed a rapid induction in accumulation of TaADF4 mRNA. Interestingly, accumulation of TaADF4 mRNA was diminished in response to inoculation with a virulent race, CYR31. Silencing of TaADF4 resulted in enhanced susceptibility to CYR23, demonstrating a role for TaADF4 in defense signaling. Using a pharmacological-based approach, coupled with an analysis of host response to pathogen infection, we observed that treatment of plants with the actin-modifying agent latrunculin B enhanced resistance to CYR23, including increased production of reactive oxygen species and enhancement of localized hypersensitive cell death. Taken together, these data support the hypothesis that TaADF4 positively modulates plant immunity in wheat via the modulation of actin cytoskeletal organization.
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Affiliation(s)
- Bing Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, Shaanxi, 712100, China
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI, 48824, USA
| | - Yuan Hua
- State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Juan Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Yan Huo
- State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Masaki Shimono
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI, 48824, USA
| | - Brad Day
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI, 48824, USA
- Plant Resilience Institute, Michigan State University, East Lansing, MI, 48824, USA
| | - Qing Ma
- State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, Shaanxi, 712100, China
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Martzoukou O, Amillis S, Zervakou A, Christoforidis S, Diallinas G. The AP-2 complex has a specialized clathrin-independent role in apical endocytosis and polar growth in fungi. eLife 2017; 6. [PMID: 28220754 PMCID: PMC5338921 DOI: 10.7554/elife.20083] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 02/07/2017] [Indexed: 12/26/2022] Open
Abstract
Filamentous fungi provide excellent systems for investigating the role of the AP-2 complex in polar growth. Using Aspergillus nidulans, we show that AP-2 has a clathrin-independent essential role in polarity maintenance and growth. This is in line with a sequence analysis showing that the AP-2 β subunit (β2) of higher fungi lacks a clathrin-binding domain, and experiments showing that AP-2 does not co-localize with clathrin. We provide genetic and cellular evidence that AP-2 interacts with endocytic markers SlaBEnd4 and SagAEnd3 and the lipid flippases DnfA and DnfB in the sub-apical collar region of hyphae. The role of AP-2 in the maintenance of proper apical membrane lipid and cell wall composition is further supported by its functional interaction with BasA (sphingolipid biosynthesis) and StoA (apical sterol-rich membrane domains), and its essentiality in polar deposition of chitin. Our findings support that the AP-2 complex of dikarya has acquired, in the course of evolution, a specialized clathrin-independent function necessary for fungal polar growth. DOI:http://dx.doi.org/10.7554/eLife.20083.001
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Affiliation(s)
- Olga Martzoukou
- Department of Biology, National and Kapodistrian University of Athens, Athens, Greece
| | - Sotiris Amillis
- Department of Biology, National and Kapodistrian University of Athens, Athens, Greece
| | - Amalia Zervakou
- Department of Biology, National and Kapodistrian University of Athens, Athens, Greece
| | - Savvas Christoforidis
- Institute of Molecular Biology and Biotechnology-Biomedical Research, Foundation for Research and Technology, Ioannina, Greece.,Laboratory of Biological Chemistry, Department of Medicine, School of Health Sciences, University of Ioannina, Ioannina, Greece
| | - George Diallinas
- Department of Biology, National and Kapodistrian University of Athens, Athens, Greece
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Schultzhaus Z, Johnson TB, Shaw BD. Clathrin localization and dynamics in Aspergillus nidulans. Mol Microbiol 2016; 103:299-318. [PMID: 27741567 DOI: 10.1111/mmi.13557] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/10/2016] [Indexed: 12/15/2022]
Abstract
Cell growth necessitates extensive membrane remodeling events including vesicle fusion or fission, processes that are regulated by coat proteins. The hyphal cells of filamentous fungi concentrate both exocytosis and endocytosis at the apex. This investigation focuses on clathrin in Aspergillus nidulans, with the aim of understanding its role in membrane remodeling in growing hyphae. We examined clathrin heavy chain (ClaH-GFP) which localized to three distinct subcellular structures: late Golgi (trans-Golgi equivalents of filamentous fungi), which are concentrated just behind the hyphal tip but are intermittently present throughout all hyphal cells; the region of concentrated endocytosis just behind the hyphal apex (the "endocytic collar"); and small, rapidly moving puncta that were seen trafficking long distances in nearly all hyphal compartments. ClaH localized to distinct domains on late Golgi, and these clathrin "hubs" dispersed in synchrony after the late Golgi marker PHOSBP . Although clathrin was essential for growth, ClaH did not colocalize well with the endocytic patch marker fimbrin. Tests of FM4-64 internalization and repression of ClaH corroborated the observation that clathrin does not play an important role in endocytosis in A. nidulans. A minor portion of ClaH puncta exhibited bidirectional movement, likely along microtubules, but were generally distinct from early endosomes.
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Affiliation(s)
- Z Schultzhaus
- Department of Plant Pathology and Microbiology, Texas A&M University, 2132 TAMU, College Station, TX, 77845, USA
| | - T B Johnson
- Department of Plant Pathology and Microbiology, Texas A&M University, 2132 TAMU, College Station, TX, 77845, USA
| | - B D Shaw
- Department of Plant Pathology and Microbiology, Texas A&M University, 2132 TAMU, College Station, TX, 77845, USA
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40
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Hernández-Ortiz P, Espeso EA. Spatiotemporal dynamics of the calcineurin target CrzA. Cell Signal 2016; 29:168-180. [PMID: 27832964 DOI: 10.1016/j.cellsig.2016.11.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Revised: 09/26/2016] [Accepted: 11/05/2016] [Indexed: 01/23/2023]
Abstract
The response of Aspergilli to elevated concentrations of extracellular calcium and manganese, or environmental alkalinization is mediated by CrzA, a calcineurin-responsive transcription factor (TF). CrzA is the effector of a signaling pathway which includes the apical protein's calmodulin and calcineurin, and the protein kinases GskA and CkiA. Preferentially located in the cytoplasm, CrzA is the only element of the pathway modifying its localization under those stress conditions, being imported into nuclei. Remarkably, there is a direct relationship between the nature/intensity of the stimulus and the pace of nuclear import and time of nuclear permanence of CrzA. Alkalinity caused a transient nuclear accumulation of CrzA while high Ca2+ and Mn2+ concentrations generated a long-lasting accumulation. Furthermore, Ca2+ concentrations (below 5mM) that are non-toxic for a crzAΔ mutant promoted full signaling of CrzA. However, micromolar concentrations or a mutation disrupting the interaction of CrzA with the phosphatase complex calcineurin, permitted the visualization of a transient and polarized nuclear accumulation of the TF in a tip-to-base gradient. Overall, these results support a model in which nucleo-cytoplasmic dynamics and transcriptional activity of CrzA are driven by apical signals transmitted by calmodulin and calcineurin. This communication is essential to understand Ca+2-induced stress response in fungi.
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Affiliation(s)
- Patricia Hernández-Ortiz
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas, CSIC, Madrid, Spain
| | - Eduardo A Espeso
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas, CSIC, Madrid, Spain.
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Bergs A, Ishitsuka Y, Evangelinos M, Nienhaus GU, Takeshita N. Dynamics of Actin Cables in Polarized Growth of the Filamentous Fungus Aspergillus nidulans. Front Microbiol 2016; 7:682. [PMID: 27242709 PMCID: PMC4860496 DOI: 10.3389/fmicb.2016.00682] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 04/26/2016] [Indexed: 12/20/2022] Open
Abstract
Highly polarized growth of filamentous fungi requires a continuous supply of proteins and lipids to the hyphal tip. This transport is managed by vesicle trafficking via the actin and microtubule cytoskeletons and their associated motor proteins. Particularly, actin cables originating from the hyphal tip are essential for hyphal growth. Although, specific marker proteins have been developed to visualize actin cables in filamentous fungi, the exact organization and dynamics of actin cables has remained elusive. Here, we observed actin cables using tropomyosin (TpmA) and Lifeact fused to fluorescent proteins in living Aspergillus nidulans hyphae and studied the dynamics and regulation. GFP tagged TpmA visualized dynamic actin cables formed from the hyphal tip with cycles of elongation and shrinkage. The elongation and shrinkage rates of actin cables were similar and approximately 0.6 μm/s. Comparison of actin markers revealed that high concentrations of Lifeact reduced actin dynamics. Simultaneous visualization of actin cables and microtubules suggests temporally and spatially coordinated polymerization and depolymerization between the two cytoskeletons. Our results provide new insights into the molecular mechanism of ordered polarized growth regulated by actin cables and microtubules.
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Affiliation(s)
- Anna Bergs
- Department of Microbiology, Institute for Applied Bioscience, Karlsruhe Institute of Technology Karlsruhe, Germany
| | - Yuji Ishitsuka
- Institute of Applied Physics, Karlsruhe Institute of Technology Karlsruhe, Germany
| | - Minoas Evangelinos
- Department of Microbiology, Institute for Applied Bioscience, Karlsruhe Institute of TechnologyKarlsruhe, Germany; Faculty of Biology, University of AthensAthens, Greece
| | - G U Nienhaus
- Institute of Applied Physics, Karlsruhe Institute of TechnologyKarlsruhe, Germany; Institute of Toxicology and Genetics, Karlsruhe Institute of TechnologyEggenstein-Leopoldshafen, Germany; Institute of Nanotechnology, Karlsruhe Institute of TechnologyEggenstein-Leopoldshafen, Germany; Department of Physics, University of Illinois at Urbana-ChampaignUrbana-Champaign, IL, USA
| | - Norio Takeshita
- Department of Microbiology, Institute for Applied Bioscience, Karlsruhe Institute of TechnologyKarlsruhe, Germany; Faculty of Life and Environmental Sciences, University of TsukubaTsukuba, Japan
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42
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Schultzhaus Z, Quintanilla L, Hilton A, Shaw BD. Live Cell Imaging of Actin Dynamics in the Filamentous Fungus Aspergillus nidulans. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2016; 22:264-274. [PMID: 26879694 DOI: 10.1017/s1431927616000131] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Hyphal cells of filamentous fungi grow at their tips in a method analogous to pollen tube and root hair elongation. This process, generally referred to as tip growth, requires precise regulation of the actin cytoskeleton, and characterizing the various actin structures in these cell types is currently an active area of research. Here, the actin marker Lifeact was used to document actin dynamics in the filamentous fungus Aspergillus nidulans. Contractile double rings were observed at septa, and annular clusters of puncta were seen subtending growing hyphal tips, corresponding to the well-characterized subapical endocytic collar. However, Lifeact also revealed two additional structures. One, an apical array, was dynamic on the face opposite the tip, while a subapical web was dynamic on the apical face and was located several microns behind the growth site. Each was observed turning into the other over time, implying that they could represent different localizations of the same structure, although hyphae with a subapical web grew faster than those exhibiting an apical array. The subapical web has not been documented in any filamentous fungus to date, and is separate from the networks of F-actin seen in other tip-growing organisms surrounding septa or stationary along the plasmalemma.
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Affiliation(s)
- Zachary Schultzhaus
- Department of Plant Pathology and Microbiology,Texas A&M University,College Station,TX 77843,USA
| | - Laura Quintanilla
- Department of Plant Pathology and Microbiology,Texas A&M University,College Station,TX 77843,USA
| | - Angelyn Hilton
- Department of Plant Pathology and Microbiology,Texas A&M University,College Station,TX 77843,USA
| | - Brian D Shaw
- Department of Plant Pathology and Microbiology,Texas A&M University,College Station,TX 77843,USA
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Schultzhaus Z, Shaw BD. The flippase DnfB is cargo of fimbrin-associated endocytosis in Aspergillus nidulans, and likely recycles through the late Golgi. Commun Integr Biol 2016; 9:e1141843. [PMID: 27195062 PMCID: PMC4857784 DOI: 10.1080/19420889.2016.1141843] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 01/06/2016] [Accepted: 01/08/2016] [Indexed: 12/31/2022] Open
Affiliation(s)
- Zachary Schultzhaus
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station , TX, USA
| | - Brian D Shaw
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station , TX, USA
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New Insight Into the Roles of Membrane Microdomains in Physiological Activities of Fungal Cells. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2016; 325:119-80. [PMID: 27241220 DOI: 10.1016/bs.ircmb.2016.02.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The organization of biological membranes into structurally and functionally distinct lateral microdomains is generally accepted. From bacteria to mammals, laterally compartmentalized membranes seem to be a vital attribute of life. The crucial fraction of our current knowledge about the membrane microdomains has been gained from studies on fungi. In this review we summarize the evidence of the microdomain organization of membranes from fungal cells, with accent on their enormous diversity in composition, temporal dynamics, modes of formation, and recognized engagement in the cell physiology. A special emphasis is laid on the fact that in addition to their other biological functions, membrane microdomains also mediate the communication among different membranes within a eukaryotic cell and coordinate their functions. Involvement of fungal membrane microdomains in stress sensing, regulation of lipid homeostasis, and cell differentiation is discussed more in detail.
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45
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Kilaru S, Schuster M, Latz M, Guo M, Steinberg G. Fluorescent markers of the endocytic pathway in Zymoseptoria tritici. Fungal Genet Biol 2016; 79:150-7. [PMID: 26092801 PMCID: PMC4502447 DOI: 10.1016/j.fgb.2015.03.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 03/12/2015] [Accepted: 03/17/2015] [Indexed: 12/28/2022]
Abstract
We establish Z. tritici fimbrin (ZtFim1) and small GTPases (ZtRab5, ZtRab7) as endocytic markers. All markers localize correctly, proven by live cell imaging and co-staining and pharmaceutical studies. We provide 3 carboxin-resistance conveying vectors for integration of all markers into the sdi1 locus. We provide 3 hygromycin B-resistance conveying vectors for random integration of all markers.
Hyphal growth in filamentous fungi is supported by the uptake (endocytosis) and recycling of membranes and associated proteins at the growing tip. An increasing body of published evidence in various fungi demonstrates that this process is of essential importance for fungal growth and pathogenicity. Here, we introduce fluorescent markers to visualize the endocytic pathway in the wheat pathogen Zymoseptoria tritici. We fused enhanced green-fluorescent protein (eGFP) to the actin-binding protein fimbrin (ZtFim1), which is located in actin patches that are formed at the plasma membrane and are participating in endocytic uptake at the cell surface. In addition, we tagged early endosomes by eGFP-labelling a Rab5-homologue (ZtRab5) and late endosomes and vacuoles by expressing eGFP-Rab7 homologue (ZtRab7). Using fluorescent dyes and live cell imaging we confirmed the dynamic behavior and localization of these markers. This set of molecular tools enables an in-depth phenotypic analysis of Z. tritici mutant strains thereby supporting new strategies towards the goal of controlling wheat against Z. tritici.
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Affiliation(s)
- S Kilaru
- Biosciences, University of Exeter, Exeter EX4 4QD, UK
| | - M Schuster
- Biosciences, University of Exeter, Exeter EX4 4QD, UK
| | - M Latz
- Biosciences, University of Exeter, Exeter EX4 4QD, UK
| | - M Guo
- Biosciences, University of Exeter, Exeter EX4 4QD, UK
| | - G Steinberg
- Biosciences, University of Exeter, Exeter EX4 4QD, UK.
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46
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Lara-Rojas F, Bartnicki-García S, Mouriño-Pérez RR. Localization and role of MYO-1, an endocytic protein in hyphae of Neurospora crassa. Fungal Genet Biol 2016; 88:24-34. [DOI: 10.1016/j.fgb.2016.01.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2015] [Revised: 01/15/2016] [Accepted: 01/19/2016] [Indexed: 10/22/2022]
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47
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Ishitsuka Y, Savage N, Li Y, Bergs A, Grün N, Kohler D, Donnelly R, Nienhaus GU, Fischer R, Takeshita N. Superresolution microscopy reveals a dynamic picture of cell polarity maintenance during directional growth. SCIENCE ADVANCES 2015; 1:e1500947. [PMID: 26665168 PMCID: PMC4673053 DOI: 10.1126/sciadv.1500947] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 09/14/2015] [Indexed: 05/02/2023]
Abstract
Polar (directional) cell growth, a key cellular mechanism shared among a wide range of species, relies on targeted insertion of new material at specific locations of the plasma membrane. How these cell polarity sites are stably maintained during massive membrane insertion has remained elusive. Conventional live-cell optical microscopy fails to visualize polarity site formation in the crowded cell membrane environment because of its limited resolution. We have used advanced live-cell imaging techniques to directly observe the localization, assembly, and disassembly processes of cell polarity sites with high spatiotemporal resolution in a rapidly growing filamentous fungus, Aspergillus nidulans. We show that the membrane-associated polarity site marker TeaR is transported on microtubules along with secretory vesicles and forms a protein cluster at that point of the apical membrane where the plus end of the microtubule touches. There, a small patch of membrane is added through exocytosis, and the TeaR cluster gets quickly dispersed over the membrane. There is an incessant disassembly and reassembly of polarity sites at the growth zone, and each new polarity site locus is slightly offset from preceding ones. On the basis of our imaging results and computational modeling, we propose a transient polarity model that explains how cell polarity is stably maintained during highly active directional growth.
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Affiliation(s)
- Yuji Ishitsuka
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany
| | - Natasha Savage
- Department of Functional and Comparative Genomics, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
| | - Yiming Li
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany
| | - Anna Bergs
- Department of Microbiology, Institute for Applied Biosciences, KIT, 76187 Karlsruhe, Germany
| | - Nathalie Grün
- Department of Microbiology, Institute for Applied Biosciences, KIT, 76187 Karlsruhe, Germany
| | - Daria Kohler
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany
| | - Rebecca Donnelly
- Department of Functional and Comparative Genomics, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
| | - G. Ulrich Nienhaus
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany
- Institute of Nanotechnology, KIT, 76344 Eggenstein-Leopoldshafen, Germany
- Institute of Toxicology and Genetics, KIT, 76344 Eggenstein-Leopoldshafen, Germany
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Corresponding author. E-mail: (G.U.N.); (R.F.); (N.T.)
| | - Reinhard Fischer
- Department of Microbiology, Institute for Applied Biosciences, KIT, 76187 Karlsruhe, Germany
- Corresponding author. E-mail: (G.U.N.); (R.F.); (N.T.)
| | - Norio Takeshita
- Department of Microbiology, Institute for Applied Biosciences, KIT, 76187 Karlsruhe, Germany
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
- Corresponding author. E-mail: (G.U.N.); (R.F.); (N.T.)
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48
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Yao X, Arst HN, Wang X, Xiang X. Discovery of a vezatin-like protein for dynein-mediated early endosome transport. Mol Biol Cell 2015; 26:3816-27. [PMID: 26378255 PMCID: PMC4626066 DOI: 10.1091/mbc.e15-08-0602] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 09/06/2015] [Indexed: 11/11/2022] Open
Abstract
In filamentous fungi, dynein moves early endosomes away from the hyphal tip. Aspergillus genetics is used to identify a vezatin-like protein, VezA, which is critical for dynein-mediated transport of early endosomes. VezA localizes to the hyphal tip in an actin-dependent manner and regulates the interaction between dynein and early endosomes. Early endosomes are transported bidirectionally by cytoplasmic dynein and kinesin-3, but how the movements are regulated in vivo remains unclear. Here our forward genetic study led to the discovery of VezA, a vezatin-like protein in Aspergillus nidulans, as a factor critical for early endosome distribution. Loss of vezA causes an abnormal accumulation of early endosomes at the hyphal tip, where microtubule plus ends are located. This abnormal accumulation depends on kinesin-3 and is due to a decrease in the frequency but not the speed of dynein-mediated early endosome movement. VezA-GFP signals are enriched at the hypha tip in an actin-dependent manner but are not obviously associated with early endosomes, thus differing from the early endosome association of the cargo adapter HookA (Hook in A. nidulans). On loss of VezA, HookA associates normally with early endosomes, but the interaction between dynein-dynactin and the early-endosome-bound HookA is significantly decreased. However, VezA is not required for linking dynein-dynactin to the cytosolic ∆C-HookA, lacking the cargo-binding C-terminus. These results identify VezA as a novel regulator required for the interaction between dynein and the Hook-bound early endosomes in vivo.
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Affiliation(s)
- Xuanli Yao
- Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences-F. Edward Hébert School of Medicine, Bethesda, MD 20814
| | - Herbert N Arst
- Microbiology Section, Department of Medicine, Imperial College London, London SW7 2AZ, United Kingdom
| | - Xiangfeng Wang
- School of Plant Sciences, University of Arizona, Tucson, AZ 85721
| | - Xin Xiang
- Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences-F. Edward Hébert School of Medicine, Bethesda, MD 20814
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Herrero-Garcia E, Perez-de-Nanclares-Arregi E, Cortese MS, Markina-Iñarrairaegui A, Oiartzabal-Arano E, Etxebeste O, Ugalde U, Espeso EA. Tip-to-nucleus migration dynamics of the asexual development regulator FlbB in vegetative cells. Mol Microbiol 2015; 98:607-24. [PMID: 26256571 DOI: 10.1111/mmi.13156] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/06/2015] [Indexed: 01/24/2023]
Abstract
In Aspergillus nidulans, asexual differentiation requires the presence of the transcription factor FlbB at the cell tip and apical nuclei. Understanding the relationship between these two pools is crucial for elucidating the biochemical processes mediating conidia production. Tip-to-nucleus communication was demonstrated by photo-convertible FlbB::Dendra2 visualization. Tip localization of FlbB depends on Cys382 in the C-terminus and the bZIP DNA-binding domain in the N-terminus. FlbE, a critical FlbB interactor, binds the bZIP domain. Furthermore, the absence of FlbE results in loss of tip localization but not nuclear accumulation. flbE deletion also abrogates transcriptional activity indicating that FlbB gains transcriptional competence from interactions with FlbE at the tip. Finally, a bipartite nuclear localization signal is required for nuclear localization of FlbB. Those motifs of FlbB may play various roles in the sequence of events necessary for the distribution and activation of this transcriptionally active developmental factor. The tip accumulation, FlbE-dependent activation, transport and nuclear import sketch out a process of relaying an environmentally triggered signal from the tip to the nuclei. As the first known instance of transcription factor-mediated tip-to-nucleus communication in filamentous fungi, this provides a general framework for analyses focused on elucidating the set of molecular mechanisms coupling apical signals to transcriptional events.
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Affiliation(s)
- Erika Herrero-Garcia
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas (CSIC), Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Elixabet Perez-de-Nanclares-Arregi
- Biochemistry II laboratory, Department of Applied Chemistry, Faculty of Chemistry, University of The Basque Country, 20018, San Sebastian, Spain
| | - Marc S Cortese
- Biochemistry II laboratory, Department of Applied Chemistry, Faculty of Chemistry, University of The Basque Country, 20018, San Sebastian, Spain
| | - Ane Markina-Iñarrairaegui
- Biochemistry II laboratory, Department of Applied Chemistry, Faculty of Chemistry, University of The Basque Country, 20018, San Sebastian, Spain
| | - Elixabet Oiartzabal-Arano
- Biochemistry II laboratory, Department of Applied Chemistry, Faculty of Chemistry, University of The Basque Country, 20018, San Sebastian, Spain
| | - Oier Etxebeste
- Biochemistry II laboratory, Department of Applied Chemistry, Faculty of Chemistry, University of The Basque Country, 20018, San Sebastian, Spain
| | - Unai Ugalde
- Biochemistry II laboratory, Department of Applied Chemistry, Faculty of Chemistry, University of The Basque Country, 20018, San Sebastian, Spain
| | - Eduardo A Espeso
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas (CSIC), Ramiro de Maeztu 9, 28040, Madrid, Spain
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50
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Wang CL, Shaw BD. F-actin localization dynamics during appressorium formation in Colletotrichum graminicola. Mycologia 2015; 108:506-14. [PMID: 26297784 DOI: 10.3852/15-068] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Accepted: 07/17/2015] [Indexed: 11/10/2022]
Abstract
Appressoria are essential penetration structures for many phytopathogenic fungi. Here F-actin localization dynamics were documented during appressorium formation in vitro and in planta in Colletotrichum graminicola Four discernible stages of dynamic F-actin distribution occurring in a programmed order were documented from differentiation of appressoria to formation of penetration pores: (stage A) from germ tube enlargement to complete expansion of the appressorium; (stage S) septation occurs; (stage L) a long period of low F-actin activity; (stage P) the penetration pore forms. The F-actin subcellular localization corresponded to each stage. A distinct redistribution of actin cables occurred at the transition from stage A to stage S. The in planta assays revealed that F-actin also assembled in invasive hyphae and that actin cables might play an essential role for penetration-peg development. The F-actin localization distribution may be used as a subcellular marker to define the developmental stages during appressorium formation.
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Affiliation(s)
- Chih-Li Wang
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas, and Department of Plant Pathology, National Chung Hsing University, Taichung, Taiwan
| | - Brian D Shaw
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas
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