1
|
Duan Y, Chen X, Wang T, Li M. The serine/threonine protein kinase MpSTE1 directly governs hyphal branching in Monascus spp. Appl Microbiol Biotechnol 2024; 108:255. [PMID: 38446219 PMCID: PMC10917826 DOI: 10.1007/s00253-024-13093-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 02/19/2024] [Accepted: 02/28/2024] [Indexed: 03/07/2024]
Abstract
Monascus spp. are commercially important fungi due to their ability to produce beneficial secondary metabolites such as the cholesterol-lowering agent lovastatin and natural food colorants azaphilone pigments. Although hyphal branching intensively influenced the production of these secondary metabolites, the pivotal regulators of hyphal development in Monascus spp. remain unclear. To identify these important regulators, we developed an artificial intelligence (AI)-assisted image analysis tool for quantification of hyphae-branching and constructed a random T-DNA insertion library. High-throughput screening revealed that a STE kinase, MpSTE1, was considered as a key regulator of hyphal branching based on the hyphal phenotype. To further validate the role of MpSTE1, we generated an mpSTE1 gene knockout mutant, a complemented mutant, and an overexpression mutant (OE::mpSTE1). Microscopic observations revealed that overexpression of mpSTE1 led to a 63% increase in branch number while deletion of mpSTE1 reduced the hyphal branching by 68% compared to the wild-type strain. In flask cultures, the strain OE::mpSTE1 showed accelerated growth and glucose consumption. More importantly, the strain OE::mpSTE1 produced 9.2 mg/L lovastatin and 17.0 mg/L azaphilone pigments, respectively, 47.0% and 30.1% higher than those of the wild-type strain. Phosphoproteomic analysis revealed that MpSTE1 directly phosphorylated 7 downstream signal proteins involved in cell division, cytoskeletal organization, and signal transduction. To our best knowledge, MpSTE1 is reported as the first characterized regulator for tightly regulating the hyphal branching in Monascus spp. These findings significantly expanded current understanding of the signaling pathway governing the hyphal branching and development in Monascus spp. Furthermore, MpSTE1 and its analogs were demonstrated as promising targets for improving production of valuable secondary metabolites. KEY POINTS: • MpSTE1 is the first characterized regulator for tightly regulating hyphal branching • Overexpression of mpSTE1 significantly improves secondary metabolite production • A high-throughput image analysis tool was developed for counting hyphal branching.
Collapse
Affiliation(s)
- Yali Duan
- Key Laboratory of Environment Correlative Dietology, College of Food Science and Technology, Hubei International Scientific and Technological Cooperation Base of Traditional Fermented FoodsHuazhong Agricultural UniversityHubei Province, Wuhan, 430070, China
- College of Food Science and Technology, Huazhong Agricultural University, Hubei Province, Wuhan, 430070, China
| | - Xizhu Chen
- Key Laboratory of Environment Correlative Dietology, College of Food Science and Technology, Hubei International Scientific and Technological Cooperation Base of Traditional Fermented FoodsHuazhong Agricultural UniversityHubei Province, Wuhan, 430070, China
- College of Food Science and Technology, Huazhong Agricultural University, Hubei Province, Wuhan, 430070, China
| | - Tingya Wang
- Key Laboratory of Environment Correlative Dietology, College of Food Science and Technology, Hubei International Scientific and Technological Cooperation Base of Traditional Fermented FoodsHuazhong Agricultural UniversityHubei Province, Wuhan, 430070, China
- College of Food Science and Technology, Huazhong Agricultural University, Hubei Province, Wuhan, 430070, China
| | - Mu Li
- Key Laboratory of Environment Correlative Dietology, College of Food Science and Technology, Hubei International Scientific and Technological Cooperation Base of Traditional Fermented FoodsHuazhong Agricultural UniversityHubei Province, Wuhan, 430070, China.
- College of Food Science and Technology, Huazhong Agricultural University, Hubei Province, Wuhan, 430070, China.
| |
Collapse
|
2
|
Liu N, Wang J, Yun Y, Wang J, Xu C, Wu S, Xu L, Li B, Kolodkin-Gal I, Dawood DH, Zhao Y, Ma Z, Chen Y. The NDR kinase-MOB complex FgCot1-Mob2 regulates polarity and lipid metabolism in Fusarium graminearum. Environ Microbiol 2021; 23:5505-5524. [PMID: 34347361 DOI: 10.1111/1462-2920.15698] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 07/28/2021] [Accepted: 07/29/2021] [Indexed: 01/08/2023]
Abstract
Members of the NDR (nuclear Dbf2-related) protein-kinase family are essential for cell differentiation and polarized morphogenesis. However, their functions in plant pathogenic fungi are not well understood. Here, we characterized the NDR kinase FgCot1 and its activator FgMob2 in Fusarium graminearum, a major pathogen causing Fusarium head blight (FHB) in wheat. FgCot1 and FgMob2 formed a NDR kinase-MOB protein complex. Localization assays using FgCot1-GFP or FgMob2-RFP constructs showed diverse subcellular localizations, including cytoplasm, septum, nucleus and hyphal tip. ΔFgcot1 and ΔFgmob2 exhibited serious defects in hyphal growth, polarity, fungal development and cell wall integrity as well as reduced virulence in planta. In contrast, lipid droplet accumulation was significantly increased in these two mutants. Phosphorylation of FgCot1 at two highly conserved residues (S462 and T630) as well as five new sites synergistically contributed its role in various cellular processes. In addition, non-synonymous mutations in two MAPK (mitogen-activated protein kinase) proteins, FgSte11 and FgGpmk1, partially rescued the growth defect of ΔFgmob2, indicating a functional link between the FgCot1-Mob2 complex and the FgGpmk1 signalling pathway in regulating filamentous fungal growth. These results indicated that the FgCot1-Mob2 complex is critical for polarity, fungal development, cell wall organization, lipid metabolism and virulence in F. graminearum.
Collapse
Affiliation(s)
- Na Liu
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China.,Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou, 310058, China.,College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao, 266109, China
| | - Jing Wang
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China.,Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou, 310058, China
| | - Yingzi Yun
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China.,Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou, 310058, China
| | - Jinli Wang
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China.,Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou, 310058, China
| | - Chaoyun Xu
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China.,Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou, 310058, China
| | - Siqi Wu
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China.,Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou, 310058, China
| | - Luona Xu
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China.,Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou, 310058, China
| | - Baohua Li
- College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao, 266109, China
| | - Ilana Kolodkin-Gal
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Dawood H Dawood
- Department of Agriculture Chemistry, Faculty of Agriculture, Mansoura University, Mansoura, 35516, Egypt
| | - Youfu Zhao
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Zhonghua Ma
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China.,Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou, 310058, China
| | - Yun Chen
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China.,Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou, 310058, China
| |
Collapse
|
3
|
Alder-Rangel A, Idnurm A, Brand AC, Brown AJP, Gorbushina A, Kelliher CM, Campos CB, Levin DE, Bell-Pedersen D, Dadachova E, Bauer FF, Gadd GM, Braus GH, Braga GUL, Brancini GTP, Walker GM, Druzhinina I, Pócsi I, Dijksterhuis J, Aguirre J, Hallsworth JE, Schumacher J, Wong KH, Selbmann L, Corrochano LM, Kupiec M, Momany M, Molin M, Requena N, Yarden O, Cordero RJB, Fischer R, Pascon RC, Mancinelli RL, Emri T, Basso TO, Rangel DEN. The Third International Symposium on Fungal Stress - ISFUS. Fungal Biol 2020; 124:235-252. [PMID: 32389286 DOI: 10.1016/j.funbio.2020.02.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Accepted: 02/11/2020] [Indexed: 12/19/2022]
Abstract
Stress is a normal part of life for fungi, which can survive in environments considered inhospitable or hostile for other organisms. Due to the ability of fungi to respond to, survive in, and transform the environment, even under severe stresses, many researchers are exploring the mechanisms that enable fungi to adapt to stress. The International Symposium on Fungal Stress (ISFUS) brings together leading scientists from around the world who research fungal stress. This article discusses presentations given at the third ISFUS, held in São José dos Campos, São Paulo, Brazil in 2019, thereby summarizing the state-of-the-art knowledge on fungal stress, a field that includes microbiology, agriculture, ecology, biotechnology, medicine, and astrobiology.
Collapse
Affiliation(s)
| | - Alexander Idnurm
- School of BioSciences, The University of Melbourne, VIC, Australia
| | - Alexandra C Brand
- Medical Research Council Centre for Medical Mycology at the University of Exeter, Exeter, England, UK
| | - Alistair J P Brown
- Medical Research Council Centre for Medical Mycology at the University of Exeter, Exeter, England, UK
| | - Anna Gorbushina
- Bundesanstalt für Materialforschung und -prüfung, Materials and the Environment, Berlin, Germany
| | - Christina M Kelliher
- Department of Molecular & Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Claudia B Campos
- Departamento de Ciência e Tecnologia, Universidade Federal de São Paulo, São José dos Campos, SP, Brazil
| | - David E Levin
- Boston University Goldman School of Dental Medicine, Boston, MA, USA
| | - Deborah Bell-Pedersen
- Center for Biological Clocks Research, Department of Biology, Texas A&M University, College Station, TX, USA
| | - Ekaterina Dadachova
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK, Canada
| | - Florian F Bauer
- Institute for Wine Biotechnology, Department of Viticulture and Oenology, Stellenbosch University, Matieland, South Africa
| | - Geoffrey M Gadd
- Geomicrobiology Group, School of Life Sciences, University of Dundee, Dundee, Scotland, UK
| | - Gerhard H Braus
- Department of Molecular Microbiology and Genetics, Institute of Microbiology and Genetics and Goettingen Center for Molecular Biosciences, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Gilberto U L Braga
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Guilherme T P Brancini
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Graeme M Walker
- School of Applied Sciences, Abertay University, Dundee, Scotland, UK
| | | | - István Pócsi
- Department of Molecular Biotechnology and Microbiology, University of Debrecen, Debrecen, Hungary
| | - Jan Dijksterhuis
- Westerdijk Fungal Biodiversity Institute, Utrecht, the Netherlands
| | - Jesús Aguirre
- Departamento de Biología Celular y del Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - John E Hallsworth
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast, Northern Ireland, UK
| | - Julia Schumacher
- Bundesanstalt für Materialforschung und -prüfung, Materials and the Environment, Berlin, Germany
| | - Koon Ho Wong
- Faculty of Health Sciences, University of Macau, Avenida da Universidade, Taipa, Macau SAR, China
| | - Laura Selbmann
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy; Italian National Antarctic Museum (MNA), Mycological Section, Genoa, Italy
| | | | - Martin Kupiec
- School of Molecular Cell Biology and Biotechnology, Tel Aviv University, Tel Aviv, Israel
| | - Michelle Momany
- Fungal Biology Group & Plant Biology Department, University of Georgia, Athens, GA, USA
| | - Mikael Molin
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Natalia Requena
- Molecular Phytopathology Department, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Oded Yarden
- Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jeruslaem, Rehovot 7610001, Israel
| | - Radamés J B Cordero
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, 21205, USA
| | - Reinhard Fischer
- Department of Microbiology, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Renata C Pascon
- Biological Sciences Department, Universidade Federal de São Paulo, Diadema, SP, Brazil
| | | | - Tamas Emri
- Department of Molecular Biotechnology and Microbiology, University of Debrecen, Debrecen, Hungary
| | - Thiago O Basso
- Department of Chemical Engineering, Escola Politécnica, Universidade de São Paulo, São Paulo, SP, Brazil
| | | |
Collapse
|
4
|
Sadhasivam S, Shapiro OH, Ziv C, Barda O, Zakin V, Sionov E. Synergistic Inhibition of Mycotoxigenic Fungi and Mycotoxin Production by Combination of Pomegranate Peel Extract and Azole Fungicide. Front Microbiol 2019; 10:1919. [PMID: 31481948 PMCID: PMC6710344 DOI: 10.3389/fmicb.2019.01919] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 08/05/2019] [Indexed: 12/27/2022] Open
Abstract
Fungal plant pathogens cause considerable losses in yield and quality of field crops worldwide. In addition, under specific environmental conditions, many fungi, including such as some Fusarium and Aspergillus spp., are further able to produce mycotoxins while colonizing their host, which accumulate in human and animal tissues, posing a serious threat to consumer health. Extensive use of azole fungicides in crop protection stimulated the emergence of acquired azole resistance in some plant and human fungal pathogens. Combination treatments, which become popular in clinical practice, offer an alternative strategy for managing potentially resistant toxigenic fungi and reducing the required dosage of specific drugs. In the current study we tested the effect of pomegranate peel extract (PPE) on the growth and toxin production of the mycotoxigenic fungi Aspergillus flavus and Fusarium proliferatum, both alone and in combination with the azole fungicide prochloraz (PRZ). Using time-lapse microscopy and quantitative image analysis we demonstrate significant delay of conidial germination and hyphal elongation rate in both fungi following PPE treatment in combination with PRZ. Moreover, PPE treatment reduced aflatoxin production by A. flavus up to 97%, while a combined treatment with sub-inhibitory doses of PPE and PRZ resulted in complete inhibition of toxin production over a 72 h treatment. These findings were supported by qRT-PCR analysis, showing down-regulation of key genes involved in the aflatoxin biosynthetic pathway under combined PPE/PRZ treatment al low concentrations. Our results provide first evidence for synergistic effects between the commercial drug PRZ and natural compound PPE. Future application of these findings may allow to reduce the required dosage of PRZ, and possibly additional azole drugs, to inhibit mycotoxigenic fungi, ultimately reducing potential concerns over exposure to high doses of these potentially harmful fungicides.
Collapse
Affiliation(s)
- Sudharsan Sadhasivam
- Department of Food Quality and Safety, Institute for Postharvest and Food Sciences, Agricultural Research Organization, The Volcani Center, Rishon LeZion, Israel
| | - Orr H. Shapiro
- Department of Food Quality and Safety, Institute for Postharvest and Food Sciences, Agricultural Research Organization, The Volcani Center, Rishon LeZion, Israel
| | - Carmit Ziv
- Department of Postharvest Science, Institute for Postharvest and Food Sciences, Agricultural Research Organization, The Volcani Center, Rishon LeZion, Israel
| | - Omer Barda
- Department of Food Quality and Safety, Institute for Postharvest and Food Sciences, Agricultural Research Organization, The Volcani Center, Rishon LeZion, Israel
| | - Varda Zakin
- Department of Food Quality and Safety, Institute for Postharvest and Food Sciences, Agricultural Research Organization, The Volcani Center, Rishon LeZion, Israel
| | - Edward Sionov
- Department of Food Quality and Safety, Institute for Postharvest and Food Sciences, Agricultural Research Organization, The Volcani Center, Rishon LeZion, Israel
| |
Collapse
|
5
|
Fischer MS, Glass NL. Communicate and Fuse: How Filamentous Fungi Establish and Maintain an Interconnected Mycelial Network. Front Microbiol 2019; 10:619. [PMID: 31001214 PMCID: PMC6455062 DOI: 10.3389/fmicb.2019.00619] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 03/12/2019] [Indexed: 12/22/2022] Open
Abstract
Cell-to-cell communication and cell fusion are fundamental biological processes across the tree of life. Survival is often dependent upon being able to identify nearby individuals and respond appropriately. Communication between genetically different individuals allows for the identification of potential mating partners, symbionts, prey, or predators. In contrast, communication between genetically similar (or identical) individuals is important for mediating the development of multicellular organisms or for coordinating density-dependent behaviors (i.e., quorum sensing). This review describes the molecular and genetic mechanisms that mediate cell-to-cell communication and cell fusion between cells of Ascomycete filamentous fungi, with a focus on Neurospora crassa. Filamentous fungi exist as a multicellular, multinuclear network of hyphae, and communication-mediated cell fusion is an important aspect of colony development at each stage of the life cycle. Asexual spore germination occurs in a density-dependent manner. Germinated spores (germlings) avoid cells that are genetically different at specific loci, while chemotropically engaging with cells that share identity at these recognition loci. Germlings with genetic identity at recognition loci undergo cell fusion when in close proximity, a fitness attribute that contributes to more rapid colony establishment. Communication and cell fusion also occur between hyphae in a colony, which are important for reinforcing colony architecture and supporting the development of complex structures such as aerial hyphae and sexual reproductive structures. Over 70 genes have been identified in filamentous fungi (primarily N. crassa) that are involved in kind recognition, chemotropic interactions, and cell fusion. While the hypothetical signal(s) and receptor(s) remain to be described, a dynamic molecular signaling network that regulates cell-cell interactions has been revealed, including two conserved MAP-Kinase cascades, a conserved STRIPAK complex, transcription factors, a NOX complex involved in the generation of reactive oxygen species, cell-integrity sensors, actin, components of the secretory pathway, and several other proteins. Together these pathways facilitate the integration of extracellular signals, direct polarized growth, and initiate a transcriptional program that reinforces signaling and prepares cells for downstream processes, such as membrane merger, cell fusion and adaptation to heterokaryon formation.
Collapse
Affiliation(s)
- Monika S. Fischer
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley CA, United States
| | - N. Louise Glass
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley CA, United States
- Environmental Genomics and Systems Biology Division, The Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| |
Collapse
|
6
|
Herold I, Kowbel D, Delgado-Álvarez DL, Garduño-Rosales M, Mouriño-Pérez RR, Yarden O. Transcriptional profiling and localization of GUL-1, a COT-1 pathway component, in Neurospora crassa. Fungal Genet Biol 2019; 126:1-11. [PMID: 30731203 DOI: 10.1016/j.fgb.2019.01.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 01/23/2019] [Accepted: 01/23/2019] [Indexed: 01/19/2023]
Abstract
Impairment of theNeurospora crassaCOT-1 kinase results in defects in hyphal polarity. Some of these effects are partially suppressed by inactivation of gul-1 (encoding an mRNA-binding protein involved in translational regulation). Here, we report on the transcriptional profiling of cot-1 inactivation and demonstrate that gul-1 affects transcript abundance of multiple genes in the COT-1 pathway, including processes such as cell wall remodeling, nitrogen and amino acid metabolism. The GUL-1 protein itself was found to be distributed within the entire hyphal cell, along with a clear presence of aggregates that traffic within the cytoplasm. Live imaging of GUL-1-GFP demonstrated that GUL-1 transport is microtubule-dependent. Cellular stress, as imposed by the presence of the cell wall biosynthesis inhibitor Nikkomycin Z or by nitrogen limitation, resulted in a 2-3-fold increase of GUL-1 aggregate association with nuclei. Taken together, this study demonstrates that GUL-1 affects multiple processes, its function is stress-related and linked with cellular traffic and nuclear association.
Collapse
Affiliation(s)
- Inbal Herold
- Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 761001, Israel
| | - David Kowbel
- Plant & Microbial Biology, University of California, Berkeley, Berkeley, CA 94720-3102, USA
| | - Diego L Delgado-Álvarez
- 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
| | - Rosa R Mouriño-Pérez
- Departamento de Microbiología, CICESE (Centro de Investigación Científica y Educación Superior de Ensenada), Mexico
| | - Oded Yarden
- Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 761001, Israel
| |
Collapse
|
7
|
Aharoni-Kats L, Zelinger E, Chen S, Yarden O. Altering Neurospora crassa MOB2A exposes its functions in development and affects its interaction with the NDR kinase COT1. Mol Microbiol 2018; 108:641-660. [PMID: 29600559 DOI: 10.1111/mmi.13954] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/15/2018] [Indexed: 12/30/2022]
Abstract
The Neurospora crassa Mps One Binder (MOB) proteins MOB2A and MOB2B physically interact with the Nuclear Dbf2 Related (NDR) kinase COT1 and have been shown to have overlapping functions in various aspects of asexual development. Here, we identified two N. crassa MOB2A residues, Tyr117 and Tyr119, which are potentially phosphorylated. Using phosphomimetic mob-2a mutants we have been able to establish that apart from their previously described roles, MOB2A/B are involved in additional developmental processes. Enhanced conidial germination, accompanied by conidial agglutination, in the phosphomimetic mutants indicated that MOB2A is a negative regulator of germination. Thick-section imaging of perithecia revealed slow maturation and a lack of asci alignment in the mutant strains demonstrating a role for MOB2A in sexual development. We demonstrate that even though MOB2A and MOB2B have some overlapping functions, MOB2B cannot compensate for the roles MOB2A has in conidiation and germination. Altering Tyr residues 117 and 119 impaired the physical interactions between MOB2A and COT1, most likely contributing to some of the observed effects. As cot-1 and the phosphomimetic mutants share an extragenic suppressor (gul-1), we concluded that at least some of the effects imposed by altering Tyr117 and Tyr119 are mediated by the NDR kinase.
Collapse
Affiliation(s)
- Liran Aharoni-Kats
- Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 7610000, Israel
| | - Einat Zelinger
- Centre for Scientific Imaging, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 7610000, Israel
| | - She Chen
- Proteomics Centre, The National Institute of Biological Sciences, Beijing 102206, China
| | - Oded Yarden
- Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 7610000, Israel
| |
Collapse
|
8
|
Shomin-Levi H, Yarden O. The Neurospora crassa PP2A Regulatory Subunits RGB1 and B56 Are Required for Proper Growth and Development and Interact with the NDR Kinase COT1. Front Microbiol 2017; 8:1694. [PMID: 28928725 PMCID: PMC5591878 DOI: 10.3389/fmicb.2017.01694] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 08/22/2017] [Indexed: 12/29/2022] Open
Abstract
COT1 is the founding member of the highly conserved nuclear Dbf2-related (NDR) Ser/Thr kinase family and plays a role in the regulation of polar growth and development in Neurospora crassa and other fungi. Changes in COT1 phosphorylation state have been shown to affect hyphal elongation, branching, and conidiation. The function of NDR protein kinases has been shown to be regulated by type 2A protein phosphatases (PP2As). PP2As are heterotrimers comprised of a catalytic and scaffolding protein along with an interchangeable regulatory subunit involved in determining substrate specificity. Inactivation of the N. crassa PP2A regulatory subunits rgb-1 and b56 conferred severe hyphal growth defects. Partial suppression of defects observed in the rgb-1RIP strain (but not in the Δb56 mutant) was observed in cot-1 phosphomimetic mutants, demonstrating that altering COT1 phosphorylation state can bypass, at least in part, the requirement of a functional RGB1 subunit. The functional fusion proteins RGB1::GFP and B56::GFP predominantly localized to hyphal tips and septa, respectively, indicating that their primary activity is in different cellular locations. COT1 protein forms exhibited a hyperphosphorylated gel migration pattern in an rgb-1RIP mutant background, similar to that observed when the fungus was cultured in the presence of the PP2A inhibitor cantharidin. COT1 was hypophosphorylated in a Δb56 mutant background, suggesting that this regulatory subunit may be involved in determining COT1 phosphorylation state, yet in an indirect manner. Reciprocal co-immunoprecipitation analyses, using tagged COT1, PPH1, RGB1, and B56 subunits established that these proteins physically interact. Taken together, our data determine the presence of a functional and physical link between PP2A and COT1 and show that two of the PP2A regulatory subunits interact with the kinase and determine COT1 phosphorylation state.
Collapse
Affiliation(s)
- Hila Shomin-Levi
- Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of JerusalemRehovot, Israel
| | - Oded Yarden
- Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of JerusalemRehovot, Israel
| |
Collapse
|
9
|
Herold I, Yarden O. Regulation of Neurospora crassa cell wall remodeling via the cot-1 pathway is mediated by gul-1. Curr Genet 2016; 63:145-159. [PMID: 27363849 DOI: 10.1007/s00294-016-0625-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 06/14/2016] [Accepted: 06/16/2016] [Indexed: 11/29/2022]
Abstract
Impairment of the Neurospora crassa Nuclear DBF2-related kinase-encoding gene cot-1 results in pleiotropic effects, including abnormally thick hyphal cell walls and septa. An increase in the transcript abundance of genes encoding chitin and glucan synthases and the chitinase gh18-5, but not the cell wall integrity pathway transcription factor rlm-1, accompany the phenotypic changes observed. Deletion of chs-5 or chs-7 in a cot-1 background results in a reduction of hyperbranching frequency characteristic of the cot-1 parent. gul-1 (a homologue of the yeast SSD1 gene) encodes a translational regulator and has been shown to partially suppress cot-1. We demonstrate that the high expression levels of the cell wall remodeling genes analyzed is curbed, and reaches near wild type levels, when gul-1 is inactivated. This is accompanied by morphological changes that include reduced cell wall thickness and restoration of normal chitin levels. We conclude that gul-1 is a mediator of cell wall remodeling within the cot-1 pathway.
Collapse
Affiliation(s)
- Inbal Herold
- Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, 7610000, Rehovot, Israel
| | - Oded Yarden
- Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, 7610000, Rehovot, Israel.
| |
Collapse
|
10
|
Neurospora crassa as a model organism to explore the interconnected network of the cell cycle and the circadian clock. Fungal Genet Biol 2014; 71:52-7. [PMID: 25239547 DOI: 10.1016/j.fgb.2014.08.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Accepted: 08/06/2014] [Indexed: 12/20/2022]
Abstract
Budding and fission yeast pioneered uncovering molecular mechanisms of eukaryotic cell division cycles. However, they do not possess canonical circadian clock machinery that regulates physiological processes with a period of about 24h. On the other hand, Neurospora crassa played a critical role in elucidating molecular mechanisms of circadian rhythms, but have not been utilized frequently for cell cycle studies. Recent findings demonstrate that there exists a conserved coupling between the cell cycle and the circadian clock from N.crassa to Mus musculus, which poses Neurospora as an ideal model organism to investigate molecular mechanisms and emerging behavior of the coupled network of the cell cycle and circadian rhythms. In this review, we briefly describe generic eukaryotic cell cycle regulation focusing on G1/S and G2/M transitions, and highlight that these transitions may be targeted for the circadian clock to influence timing of cell division cycles.
Collapse
|
11
|
Proper actin ring formation and septum constriction requires coordinated regulation of SIN and MOR pathways through the germinal centre kinase MST-1. PLoS Genet 2014; 10:e1004306. [PMID: 24762679 PMCID: PMC3998894 DOI: 10.1371/journal.pgen.1004306] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 02/25/2014] [Indexed: 12/17/2022] Open
Abstract
Nuclear DBF2p-related (NDR) kinases constitute a functionally conserved protein family of eukaryotic regulators that control cell division and polarity. In fungi, they function as effector kinases of the morphogenesis (MOR) and septation initiation (SIN) networks and are activated by pathway-specific germinal centre (GC) kinases. We characterized a third GC kinase, MST-1, that connects both kinase cascades. Genetic and biochemical interactions with SIN components and life cell imaging identify MST-1 as SIN-associated kinase that functions in parallel with the GC kinase SID-1 to activate the SIN-effector kinase DBF-2. SID-1 and MST-1 are both regulated by the upstream SIN kinase CDC-7, yet in an opposite manner. Aberrant cortical actomyosin rings are formed in Δmst-1, which resulted in mis-positioned septa and irregular spirals, indicating that MST-1-dependent regulation of the SIN is required for proper formation and constriction of the septal actomyosin ring. However, MST-1 also interacts with several components of the MOR network and modulates MOR activity at multiple levels. MST-1 functions as promiscuous enzyme and also activates the MOR effector kinase COT-1 through hydrophobic motif phosphorylation. In addition, MST-1 physically interacts with the MOR kinase POD-6, and dimerization of both proteins inactivates the GC kinase hetero-complex. These data specify an antagonistic relationship between the SIN and MOR during septum formation in the filamentous ascomycete model Neurospora crassa that is, at least in part, coordinated through the GC kinase MST-1. The similarity of the SIN and MOR pathways to the animal Hippo and Ndr pathways, respectively, suggests that intensive cross-communication between distinct NDR kinase modules may also be relevant for the homologous NDR kinases of higher eukaryotes. Cytokinesis is a fundamental cellular process essential for cell proliferation of uni- and multicellular organisms. The molecular pathways that regulate cytokinesis are highly complex and involve a large number of components that form elaborate interactive networks. The fungal septation initiation network (SIN) functions as tripartite kinase cascade that connects cell cycle progression with the control of cell division. Mis-regulation of the homologous Hippo pathway in animals results in excessive proliferation and formation of tumors, underscoring the conservation and importance of these kinase networks. A second morphogenesis (MOR) pathway involves homologous components and is controlling cell polarity in fungi and higher eukaryotes. Here we show that the promiscuous functioning Ste20-related kinase MST-1 has a dual role in regulating SIN and MOR network function. Moreover, SIN and MOR coordination through MST-1 can be achieved in an enzyme-independent manner through hetero-dimerization of germinal centre kinases, providing an additional level for activity regulation of signaling networks that is not dependent on phosphate transfer. Given the functional conservation of NDR kinase signaling modules and their regulation, our work may define general mechanisms by which NDR kinase pathway are coordinated in fungi and higher eukaryotes.
Collapse
|
12
|
Feldman D, Ziv C, Gorovits R, Efrat M, Yarden O. Neurospora crassa protein arginine methyl transferases are involved in growth and development and interact with the NDR kinase COT1. PLoS One 2013; 8:e80756. [PMID: 24260473 PMCID: PMC3834314 DOI: 10.1371/journal.pone.0080756] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Accepted: 10/11/2013] [Indexed: 11/18/2022] Open
Abstract
The protein arginine methyltransferaseas (PRMTs) family is conserved from yeast to human, and regulates stability, localization and activity of proteins. We have characterized deletion strains corresponding to genes encoding for PRMT1/3/5 (designated amt-1, amt-3 and skb-1, respectively) in Neurospora crassa. Deletion of PRMT-encoding genes conferred altered Arg-methylated protein profiles, as determined immunologically. Δamt-1 exhibited reduced hyphal elongation rates (70% of wild type) and increased susceptibility to the ergosterol biosynthesis inhibitor voriconazole. In ▵amt-3, distances between branches were significantly longer than the wild type, suggesting this gene is required for proper regulation of hyphal branching. Deletion of skb-1 resulted in hyper conidiation (2-fold of the wild type) and increased tolerance to the chitin synthase inhibitor polyoxin D. Inactivation of two Type I PRMTs (amt-1 and amt-3) conferred changes in both asymmetric as well as symmetric protein methylation profiles, suggesting either common substrates and/or cross-regulation of different PRMTs. The PRMTs in N. crassa apparently share cellular pathways which were previously reported to be regulated by the NDR (Nuclear DBF2-related) kinase COT1. Using co-immunprecipitation experiments (with MYC-tagged proteins), we have shown that SKB1 and COT1 physically interacted and the abundance of the 75 kDa MYC::COT1 isoform was increased in a Δskb-1 background. On the basis of immunological detection, we propose the possible involvement of PRMTs in Arg-methylation of COT1.
Collapse
Affiliation(s)
- Daria Feldman
- Department of Plant Pathology and Microbiology, The R.H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | | | | | | | | |
Collapse
|
13
|
Heilig Y, Schmitt K, Seiler S. Phospho-regulation of the Neurospora crassa septation initiation network. PLoS One 2013; 8:e79464. [PMID: 24205386 PMCID: PMC3804505 DOI: 10.1371/journal.pone.0079464] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Accepted: 09/28/2013] [Indexed: 01/04/2023] Open
Abstract
Proper cell division is essential for growth and development of uni- and multicellular organisms. The fungal septation initiation network (SIN) functions as kinase cascade that connects cell cycle progression with the initiation of cytokinesis. Miss-regulation of the homologous Hippo pathway in animals results in excessive cell proliferation and formation of tumors, underscoring the conservation of both pathways. How SIN proteins interact and transmit signals through the cascade is only beginning to be understood. Moreover, our understanding of septum formation and its regulation in filamentous fungi, which represent the vast majority of the fungal kingdom, is highly fragmentary. We determined that a tripartite kinase cascade, consisting of CDC-7, SID-1 and DBF-2, together with their regulatory subunits CDC-14 and MOB-1, is important for septum formation in the model mold Neurospora crassa. DBF-2 activity and septum formation requires auto-phosphorylation at Ser499 within the activation segment and phosphorylation of Thr671 in the hydrophobic motif by SID-1. Moreover, SID-1-stimulated DBF-2 activity is further enhanced by CDC-7, supporting a stepwise activation mechanism of the tripartite SIN kinase cascade in fungi. However, in contrast to the situation described for unicellular yeasts, the localization of the entire SIN cascade to spindle pole bodies is constitutive and cell cycle independent. Moreover, all SIN proteins except CDC-7 form cortical rings prior to septum initiation and localize to constricting septa. Thus, SIN localization and activity regulation significantly differs in unicellular versus syncytial ascomycete fungi.
Collapse
Affiliation(s)
- Yvonne Heilig
- Institute for Biology II – Molecular Plant Physiology, Albert-Ludwigs University Freiburg, Freiburg, Germany
| | - Kerstin Schmitt
- Institute for Microbiology and Genetics, University of Goettingen, Goettingen, Germany
| | - Stephan Seiler
- Institute for Biology II – Molecular Plant Physiology, Albert-Ludwigs University Freiburg, Freiburg, Germany
- Freiburg Institute for Advanced Studies (FRIAS), Albert-Ludwigs University Freiburg, Freiburg, Germany
- * E-mail:
| |
Collapse
|
14
|
Dettmann A, Heilig Y, Ludwig S, Schmitt K, Illgen J, Fleißner A, Valerius O, Seiler S. HAM-2 and HAM-3 are central for the assembly of the Neurospora STRIPAK complex at the nuclear envelope and regulate nuclear accumulation of the MAP kinase MAK-1 in a MAK-2-dependent manner. Mol Microbiol 2013; 90:796-812. [PMID: 24028079 DOI: 10.1111/mmi.12399] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/10/2013] [Indexed: 12/20/2022]
Abstract
Intercellular communication and somatic cell fusion are important for fungal colony establishment, multicellular differentiation and have been associated with host colonization and virulence of pathogenic species. By a combination of genetic, biochemical and live cell imaging techniques, we characterized the Neurospora crassa STRIPAK complex that is essential for self-signalling and consists of the six proteins HAM-2/STRIP, HAM-3/striatin, HAM-4/SLMAP, MOB-3/phocein, PPG-1/PP2A-C and PP2A-A. We describe that the core STRIPAK components HAM-2 and HAM-3 are central for the assembly of the complex at the nuclear envelope, while the phosphatase PPG-1 only transiently associates with this central subcomplex. Our data connect the STRIPAK complex with two MAP kinase pathways: (i) nuclear accumulation of the cell wall integrity MAP kinase MAK-1 depends on the functional integrity of the STRIPAK complex at the nuclear envelope, and (ii) phosphorylation of MOB-3 by the MAP kinase MAK-2 impacts the nuclear accumulation of MAK-1. In summary, these data support a model, in which MAK-2-dependent phosphorylation of MOB-3 is part of a MAK-1 import mechanism. Although self-communication remained intact in the absence of nuclear MAK-1 accumulation, supporting the presence of multiple mechanisms that co-ordinate robust intercellular communication, proper fruiting body morphology was dependent on the MAK-2-phosphorylated N-terminus of MOB-3.
Collapse
Affiliation(s)
- Anne Dettmann
- Institute for Biology II - Molecular Plant Physiology, Albert-Ludwigs University Freiburg, Schänzlestr. 1, 79104, Freiburg, Germany
| | | | | | | | | | | | | | | |
Collapse
|
15
|
Ziv C, Feldman D, Aharoni-Kats L, Chen S, Liu Y, Yarden O. The N-terminal region of the Neurospora NDR kinase COT1 regulates morphology via its interactions with MOB2A/B. Mol Microbiol 2013; 90:383-99. [PMID: 23962317 DOI: 10.1111/mmi.12371] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/16/2013] [Indexed: 12/15/2022]
Abstract
Nuclear Dbf2p-related (NDR) protein kinases are important for cell differentiation and polar morphogenesis in various organisms, yet some of their functions are still elusive. Dysfunction of the Neurospora crassa NDR kinase COT1 leads to cessation of tip extension and hyperbranching. NDR kinases require the physical interaction between the kinase's N-terminal region (NTR) and the MPS1-binding (MOB) proteins for their activity and functions. To study the interactions between COT1 and MOB2 proteins, we mutated several conserved residues and a novel phosphorylation site within the COT1 NTR. The phenotypes of these mutants suggest that the NTR is required for COT1 functions in regulating hyphal elongation and branching, asexual conidiation and germination. Interestingly, while both MOB2A and MOB2B promote proper hyphal growth, they have distinct COT1-dependent roles in regulation of macroconidiation. Immunoprecipitation experiments indicate physical association of COT1 with both MOB2A and MOB2B, simultaneously. Furthermore, the binding of the two MOB2 proteins to COT1 is mediated by different residues at the COT1 NTR, suggesting a hetero-trimer is formed. Thus, although MOB2A/B may have some overlapping functions in regulating hyphal tip extension, their function is not redundant and they are both required for proper fungal development.
Collapse
Affiliation(s)
- Carmit Ziv
- Department of Plant Pathology and Microbiology, The Otto Warburg Minerva Center for Agricultural Biotechnology, Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, Rehovot, 76100, Israel
| | | | | | | | | | | |
Collapse
|
16
|
Abstract
The filamentous fungi are an ecologically important group of organisms which also have important industrial applications but devastating effects as pathogens and agents of food spoilage. Protein kinases have been implicated in the regulation of virtually all biological processes but how they regulate filamentous fungal specific processes is not understood. The filamentous fungus Aspergillus nidulans has long been utilized as a powerful molecular genetic system and recent technical advances have made systematic approaches to study large gene sets possible. To enhance A. nidulans functional genomics we have created gene deletion constructs for 9851 genes representing 93.3% of the encoding genome. To illustrate the utility of these constructs, and advance the understanding of fungal kinases, we have systematically generated deletion strains for 128 A. nidulans kinases including expanded groups of 15 histidine kinases, 7 SRPK (serine-arginine protein kinases) kinases and an interesting group of 11 filamentous fungal specific kinases. We defined the terminal phenotype of 23 of the 25 essential kinases by heterokaryon rescue and identified phenotypes for 43 of the 103 non-essential kinases. Uncovered phenotypes ranged from almost no growth for a small number of essential kinases implicated in processes such as ribosomal biosynthesis, to conditional defects in response to cellular stresses. The data provide experimental evidence that previously uncharacterized kinases function in the septation initiation network, the cell wall integrity and the morphogenesis Orb6 kinase signaling pathways, as well as in pathways regulating vesicular trafficking, sexual development and secondary metabolism. Finally, we identify ChkC as a third effector kinase functioning in the cellular response to genotoxic stress. The identification of many previously unknown functions for kinases through the functional analysis of the A. nidulans kinome illustrates the utility of the A. nidulans gene deletion constructs.
Collapse
|
17
|
Antal Z, Rascle C, Cimerman A, Viaud M, Billon-Grand G, Choquer M, Bruel C. The homeobox BcHOX8 gene in Botrytis cinerea regulates vegetative growth and morphology. PLoS One 2012; 7:e48134. [PMID: 23133556 PMCID: PMC3485016 DOI: 10.1371/journal.pone.0048134] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Accepted: 09/27/2012] [Indexed: 11/19/2022] Open
Abstract
Filamentous growth and the capacity at producing conidia are two critical aspects of most fungal life cycles, including that of many plant or animal pathogens. Here, we report on the identification of a homeobox transcription factor encoding gene that plays a role in these two particular aspects of the development of the phytopathogenic fungus Botrytis cinerea. Deletion of the BcHOX8 gene in both the B. cinerea B05-10 and T4 strains causes similar phenotypes, among which a curved, arabesque-like, hyphal growth on hydrophobic surfaces; the mutants were hence named Arabesque. Expression of the BcHOX8 gene is higher in conidia and infection cushions than in developing appressorium or mycelium. In the Arabesque mutants, colony growth rate is reduced and abnormal infection cushions are produced. Asexual reproduction is also affected with abnormal conidiophore being formed, strongly reduced conidia production and dramatic changes in conidial morphology. Finally, the mutation affects the fungus ability to efficiently colonize different host plants. Analysis of the B. cinerea genome shows that BcHOX8 is one member of a nine putative homeobox genes family. Available gene expression data suggest that these genes are functional and sequence comparisons indicate that two of them would be specific to B. cinerea and its close relative Sclerotinia sclerotiorum.
Collapse
Affiliation(s)
- Zsuzsanna Antal
- Unité Mixte de Recherche 5240 - Microbiologie, Adaptation et Pathogénie; Université Lyon 1, CNRS, Bayer CropScience, Villeurbanne, France
| | - Christine Rascle
- Unité Mixte de Recherche 5240 - Microbiologie, Adaptation et Pathogénie; Université Lyon 1, CNRS, Bayer CropScience, Villeurbanne, France
| | - Agnès Cimerman
- Biologie et Gestion des Risques en Agriculture - Champignons Pathogènes des Plantes, INRA 1290, Thiverval-Grignon, France
| | - Muriel Viaud
- Biologie et Gestion des Risques en Agriculture - Champignons Pathogènes des Plantes, INRA 1290, Thiverval-Grignon, France
| | - Geneviève Billon-Grand
- Unité Mixte de Recherche 5240 - Microbiologie, Adaptation et Pathogénie; Université Lyon 1, CNRS, Bayer CropScience, Villeurbanne, France
| | - Mathias Choquer
- Unité Mixte de Recherche 5240 - Microbiologie, Adaptation et Pathogénie; Université Lyon 1, CNRS, Bayer CropScience, Villeurbanne, France
| | - Christophe Bruel
- Unité Mixte de Recherche 5240 - Microbiologie, Adaptation et Pathogénie; Université Lyon 1, CNRS, Bayer CropScience, Villeurbanne, France
- * E-mail:
| |
Collapse
|
18
|
Dettmann A, Illgen J, März S, Schürg T, Fleissner A, Seiler S. The NDR kinase scaffold HYM1/MO25 is essential for MAK2 map kinase signaling in Neurospora crassa. PLoS Genet 2012; 8:e1002950. [PMID: 23028357 PMCID: PMC3447951 DOI: 10.1371/journal.pgen.1002950] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Accepted: 07/30/2012] [Indexed: 12/22/2022] Open
Abstract
Cell communication is essential for eukaryotic development, but our knowledge of molecules and mechanisms required for intercellular communication is fragmentary. In particular, the connection between signal sensing and regulation of cell polarity is poorly understood. In the filamentous ascomycete Neurospora crassa, germinating spores mutually attract each other and subsequently fuse. During these tropic interactions, the two communicating cells rapidly alternate between two different physiological states, probably associated with signal delivery and response. The MAK2 MAP kinase cascade mediates cell–cell signaling. Here, we show that the conserved scaffolding protein HYM1/MO25 controls the cell shape-regulating NDR kinase module as well as the signal-receiving MAP kinase cascade. HYM1 functions as an integral part of the COT1 NDR kinase complex to regulate the interaction with its upstream kinase POD6 and thereby COT1 activity. In addition, HYM1 interacts with NRC1, MEK2, and MAK2, the three kinases of the MAK2 MAP kinase cascade, and co-localizes with MAK2 at the apex of growing cells. During cell fusion, the three kinases of the MAP kinase module as well as HYM1 are recruited to the point of cell–cell contact. hym-1 mutants phenocopy all defects observed for MAK2 pathway mutants by abolishing MAK2 activity. An NRC1-MEK2 fusion protein reconstitutes MAK2 signaling in hym-1, while constitutive activation of NRC1 and MEK2 does not. These data identify HYM1 as a novel regulator of the NRC1-MEK2-MAK2 pathway, which may coordinate NDR and MAP kinase signaling during cell polarity and intercellular communication. Intercellular communication and cellular morphogenesis are essential for eukaryotic development. Our knowledge of molecules and mechanisms associated with these processes is, however, fragmentary. In particular, the molecular connection between signal sensing and regulation of cell polarity is poorly understood. Fungal hyphae share with neurons and pollen tubes the distinction of being amongst the most highly polarized cells in biology. The robust genetic tractability of filamentous fungi provides an unparalleled opportunity to determine common principles that underlie polarized growth and its regulation through cell communication. In Neurospora crassa, germinating spores mutually attract each other, establish physical contact through polarized tropic growth, and fuse. During this process, the cells rapidly alternate between two different physiological states, probably associated with signal delivery and response. Here, we show that the conserved scaffolding protein HYM1/MO25 interacts with the polarity and cell shape-regulating NDR kinase complex as well as a MAP kinase module, which is essential for cell communication during the tropic interaction. We propose that this dual use of a common regulator in both molecular complexes may represent an intriguing mechanism of linking the perception of external cues with the polarization machinery to coordinate communication and tropic growth of interacting cells.
Collapse
Affiliation(s)
- Anne Dettmann
- Institute for Microbiology and Genetics, University of Goettingen, Goettingen, Germany
| | - Julia Illgen
- Institute for Genetics, Technische Universität Braunschweig, Braunschweig, Germany
| | - Sabine März
- Institute for Microbiology and Genetics, University of Goettingen, Goettingen, Germany
| | - Timo Schürg
- Institute for Genetics, Technische Universität Braunschweig, Braunschweig, Germany
| | - Andre Fleissner
- Institute for Genetics, Technische Universität Braunschweig, Braunschweig, Germany
| | - Stephan Seiler
- Institute for Microbiology and Genetics, University of Goettingen, Goettingen, Germany
- * E-mail:
| |
Collapse
|
19
|
Sartorel E, Pérez-Martín J. The distinct interaction between cell cycle regulation and the widely conserved morphogenesis-related (MOR) pathway in the fungus Ustilago maydis determines morphology. J Cell Sci 2012; 125:4597-608. [PMID: 22767510 DOI: 10.1242/jcs.107862] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The morphogenesis-related NDR kinase (MOR) pathway regulates morphogenesis in fungi. In spite of the high conservation of its components, impairing their functions results in highly divergent cellular responses depending on the fungal species. The reasons for such differences are unclear. Here we propose that the species-specific connections between cell cycle regulation and the MOR pathway could be partly responsible for these divergences. We based our conclusion on the characterization of the MOR pathway in the fungus Ustilago maydis. Each gene that encodes proteins of this pathway in U. maydis was deleted. All mutants exhibited a constitutive hyperpolarized growth, contrasting with the loss of polarity observed in other fungi. Using a conditional allele of the central NDR kinase Ukc1, we found that impairing MOR function resulted in a prolonged G2 phase. This cell cycle delay appears to be the consequence of an increase in Cdk1 inhibitory phosphorylation. Strikingly, prevention of the inhibitory Cdk1 phosphorylation abolished the hyperpolarized growth associated with MOR pathway depletion. We found that the prolonged G2 phase resulted in higher levels of expression of crk1, a conserved kinase that promotes polar growth in U. maydis. Deletion of crk1 also abolished the dramatic activation of polar growth in cells lacking the MOR pathway. Taken together, our results suggest that Cdk1 inhibitory phosphorylation may act as an integrator of signaling cascades regulating fungal morphogenesis and that the distinct morphological response observed in U. maydis upon impairment of the MOR pathway could be due to a cell cycle deregulation.
Collapse
Affiliation(s)
- Elodie Sartorel
- Instituto de Biología Funcional y Genómica (CSIC), 37007 Salamanca, Spain
| | | |
Collapse
|
20
|
Abstract
Filamentous growth is a nutrient-regulated growth response that occurs in many fungal species. In pathogens, filamentous growth is critical for host-cell attachment, invasion into tissues, and virulence. The budding yeast Saccharomyces cerevisiae undergoes filamentous growth, which provides a genetically tractable system to study the molecular basis of the response. Filamentous growth is regulated by evolutionarily conserved signaling pathways. One of these pathways is a mitogen activated protein kinase (MAPK) pathway. A remarkable feature of the filamentous growth MAPK pathway is that it is composed of factors that also function in other pathways. An intriguing challenge therefore has been to understand how pathways that share components establish and maintain their identity. Other canonical signaling pathways-rat sarcoma/protein kinase A (RAS/PKA), sucrose nonfermentable (SNF), and target of rapamycin (TOR)-also regulate filamentous growth, which raises the question of how signals from multiple pathways become integrated into a coordinated response. Together, these pathways regulate cell differentiation to the filamentous type, which is characterized by changes in cell adhesion, cell polarity, and cell shape. How these changes are accomplished is also discussed. High-throughput genomics approaches have recently uncovered new connections to filamentous growth regulation. These connections suggest that filamentous growth is a more complex and globally regulated behavior than is currently appreciated, which may help to pave the way for future investigations into this eukaryotic cell differentiation behavior.
Collapse
|
21
|
Hydrophobic motif phosphorylation coordinates activity and polar localization of the Neurospora crassa nuclear Dbf2-related kinase COT1. Mol Cell Biol 2012; 32:2083-98. [PMID: 22451488 DOI: 10.1128/mcb.06263-11] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Nuclear Dbf2p-related (NDR) kinases and associated proteins are recognized as a conserved network that regulates eukaryotic cell polarity. NDR kinases require association with MOB adaptor proteins and phosphorylation of two conserved residues in the activation segment and hydrophobic motif for activity and function. We demonstrate that the Neurospora crassa NDR kinase COT1 forms inactive dimers via a conserved N-terminal extension, which is also required for the interaction of the kinase with MOB2 to generate heterocomplexes with basal activity. Basal kinase activity also requires autophosphorylation of the COT1-MOB2 complex in the activation segment, while hydrophobic motif phosphorylation of COT1 by the germinal center kinase POD6 fully activates COT1 through induction of a conformational change. Hydrophobic motif phosphorylation is also required for plasma membrane association of the COT1-MOB2 complex. MOB2 further restricts the membrane-associated kinase complex to the hyphal apex to promote polar cell growth. These data support an integrated mechanism of NDR kinase regulation in vivo, in which kinase activation and cellular localization of COT1 are coordinated by dual phosphorylation and interaction with MOB2.
Collapse
|
22
|
Wang C, Zhang S, Hou R, Zhao Z, Zheng Q, Xu Q, Zheng D, Wang G, Liu H, Gao X, Ma JW, Kistler HC, Kang Z, Xu JR. Functional analysis of the kinome of the wheat scab fungus Fusarium graminearum. PLoS Pathog 2011; 7:e1002460. [PMID: 22216007 PMCID: PMC3245316 DOI: 10.1371/journal.ppat.1002460] [Citation(s) in RCA: 225] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Accepted: 11/11/2011] [Indexed: 02/04/2023] Open
Abstract
As in other eukaryotes, protein kinases play major regulatory roles in filamentous fungi. Although the genomes of many plant pathogenic fungi have been sequenced, systematic characterization of their kinomes has not been reported. The wheat scab fungus Fusarium graminearum has 116 protein kinases (PK) genes. Although twenty of them appeared to be essential, we generated deletion mutants for the other 96 PK genes, including 12 orthologs of essential genes in yeast. All of the PK mutants were assayed for changes in 17 phenotypes, including growth, conidiation, pathogenesis, stress responses, and sexual reproduction. Overall, deletion of 64 PK genes resulted in at least one of the phenotypes examined, including three mutants blocked in conidiation and five mutants with increased tolerance to hyperosmotic stress. In total, 42 PK mutants were significantly reduced in virulence or non-pathogenic, including mutants deleted of key components of the cAMP signaling and three MAPK pathways. A number of these PK genes, including Fg03146 and Fg04770 that are unique to filamentous fungi, are dispensable for hyphal growth and likely encode novel fungal virulence factors. Ascospores play a critical role in the initiation of wheat scab. Twenty-six PK mutants were blocked in perithecia formation or aborted in ascosporogenesis. Additional 19 mutants were defective in ascospore release or morphology. Interestingly, F. graminearum contains two aurora kinase genes with distinct functions, which has not been reported in fungi. In addition, we used the interlog approach to predict the PK-PK and PK-protein interaction networks of F. graminearum. Several predicted interactions were verified with yeast two-hybrid or co-immunoprecipitation assays. To our knowledge, this is the first functional characterization of the kinome in plant pathogenic fungi. Protein kinase genes important for various aspects of growth, developmental, and infection processes in F. graminearum were identified in this study. Fusarium head blight caused by Fusarium graminearum is one of the most important diseases on wheat and barley. Although protein kinases are known to play major regulatory roles in fungi, systematic characterization of fungal kinomes has not been reported in plant pathogens. In this study we generated deletion mutants for 96 protein kinase genes. All of the resulting knockout mutants were assayed for changes in 17 phenotypes, including growth, reproduction, stress responses, and plant infection. Overall, deletion of 64 kinase genes resulted in at least one of the phenotypes examined. In total, 42 kinase mutants were significantly reduced in virulence or non-pathogenic. A number of these protein kinase genes, including two that are unique to filamentous fungi, are dispensable for hyphal growth and likely encode novel fungal virulence factors. Ascospores are the primary inoculum for wheat scab. We identified 26 mutants blocked in ascospore. We also used the in silico approach to predict the kinase-kinase interactions and verified some of them by yeast two-hybrid or co-IP assays. Overall, in this study we functionally characterize the kinome of F. graminearum. Protein kinase genes that are important for various aspects of growth, developmental, and plant infection processes were identified.
Collapse
Affiliation(s)
- Chenfang Wang
- Purdue-NWAFU Joint Research Center and State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shanxi, China
| | - Shijie Zhang
- Purdue-NWAFU Joint Research Center and State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shanxi, China
| | - Rui Hou
- Purdue-NWAFU Joint Research Center and State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shanxi, China
| | - Zhongtao Zhao
- Purdue-NWAFU Joint Research Center and State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shanxi, China
| | - Qian Zheng
- Purdue-NWAFU Joint Research Center and State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shanxi, China
| | - Qijun Xu
- Purdue-NWAFU Joint Research Center and State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shanxi, China
| | - Dawei Zheng
- Purdue-NWAFU Joint Research Center and State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shanxi, China
| | - Guanghui Wang
- Purdue-NWAFU Joint Research Center and State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shanxi, China
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana, United States of America
| | - Huiquan Liu
- Purdue-NWAFU Joint Research Center and State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shanxi, China
| | - Xuli Gao
- Purdue-NWAFU Joint Research Center and State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shanxi, China
| | - Ji-Wen Ma
- Purdue-NWAFU Joint Research Center and State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shanxi, China
| | - H. Corby Kistler
- USDA ARS Cereal Disease Laboratory, University of Minnesota, St. Paul, Minnesota, United States of America
| | - Zhensheng Kang
- Purdue-NWAFU Joint Research Center and State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shanxi, China
- * E-mail: (JRX); (ZK)
| | - Jin-Rong Xu
- Purdue-NWAFU Joint Research Center and State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shanxi, China
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana, United States of America
- * E-mail: (JRX); (ZK)
| |
Collapse
|
23
|
Architecture and development of the Neurospora crassa hypha – a model cell for polarized growth. Fungal Biol 2011; 115:446-74. [PMID: 21640311 DOI: 10.1016/j.funbio.2011.02.008] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2010] [Revised: 02/08/2011] [Accepted: 02/09/2011] [Indexed: 11/20/2022]
|
24
|
Costantino V, Mangoni A, Teta R, Kra-Oz G, Yarden O. Neurosporaside, a tetraglycosylated sphingolipid from Neurospora crassa. JOURNAL OF NATURAL PRODUCTS 2011; 74:554-558. [PMID: 21425845 DOI: 10.1021/np1009493] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The new tetraglycosylceramide neurosporaside (1a) has been isolated from the fungus Neurospora crassa. Neurosporaside is a tetraglycosylated glycosphingolipid characterized by a sugar chain unprecedented among natural glycoconjugates. The structure of neurosporaside was elucidated by extensive spectroscopic analysis and microscale degradation analysis, which allowed full structure elucidation using less than 1 mg of compound.
Collapse
Affiliation(s)
- Valeria Costantino
- Dipartimento di Chimica delle Sostanze Naturali, Università degli Studi di Napoli Federico II, Via D. Montesano 49, 80131 Napoli, Italy.
| | | | | | | | | |
Collapse
|
25
|
Kastner PM, Schleicher M, Müller-Taubenberger A. The NDR Family Kinase NdrA of Dictyostelium Localizes to the Centrosome and Is Required for Efficient Phagocytosis. Traffic 2011; 12:301-12. [DOI: 10.1111/j.1600-0854.2010.01147.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
26
|
Mitotic exit control of the Saccharomyces cerevisiae Ndr/LATS kinase Cbk1 regulates daughter cell separation after cytokinesis. Mol Cell Biol 2010; 31:721-35. [PMID: 21135117 DOI: 10.1128/mcb.00403-10] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Saccharomyces cerevisiae cell division ends with destruction of a septum deposited during cytokinesis; this must occur only after the structure's construction is complete. Genes involved in septum destruction are induced by the transcription factor Ace2, which is activated by the kinase Cbk1, an Ndr/LATS-related protein that functions in a system related to metazoan hippo pathways. Phosphorylation of a conserved hydrophobic motif (HM) site regulates Cbk1; at peak levels in late mitosis we found that approximately 3% of Cbk1 carries this modification. HM site phosphorylation prior to mitotic exit occurs in response to activation of the FEAR (Cdc fourteen early anaphase release) pathway. However, HM site phosphorylation is not sufficient for Cbk1 to act on Ace2: the kinase is also negatively regulated prior to cytokinesis, likely by cyclin-dependent kinase (CDK) phosphorylation. Cbk1 cannot phosphorylate Ace2 until after mitotic exit network (MEN)-initiated release of the phosphatase Cdc14. Treatment of Cbk1 with Cdc14 in vitro does not increase its intrinsic enzymatic activity, but Cdc14 is required for Cbk1 function in vivo. Thus, we propose that Cdc14 coordinates cell separation with mitotic exit via FEAR-initiated phosphorylation of the Cbk1 HM site and MEN-activated reversal of mitotic CDK phosphorylations that block both Cbk1 and Ace2 function.
Collapse
|
27
|
Tales of RAM and MOR: NDR kinase signaling in fungal morphogenesis. Curr Opin Microbiol 2010; 13:663-71. [DOI: 10.1016/j.mib.2010.08.010] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2010] [Accepted: 08/30/2010] [Indexed: 02/04/2023]
|
28
|
The NDR kinase DBF-2 is involved in regulation of mitosis, conidial development, and glycogen metabolism in Neurospora crassa. EUKARYOTIC CELL 2009; 9:502-13. [PMID: 19966031 DOI: 10.1128/ec.00230-09] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Neurospora crassa dbf-2 encodes an NDR (nuclear Dbf2-related) protein kinase, homologous to LATS1, a core component of the Hippo pathway. This pathway plays important roles in restraining cell proliferation and promoting apoptosis in differentiating cells. Here, we demonstrate that DBF-2 is involved in three fundamental processes in a filamentous fungus: cell cycle regulation, glycogen biosynthesis, and conidiation. DBF-2 is predominantly localized to the nucleus, and most (approximately 60%) dbf-2 null mutant nuclei are delayed in mitosis, indicating that DBF-2 activity is required for properly completing the cell cycle. The dbf-2 mutant exhibits reduced basal hyphal extension rates accompanied by a carbon/nitrogen ratio-dependent bursting of hyphal tips, vast glycogen leakage, defects in aerial hypha formation, and impairment of all three asexual conidiation pathways in N. crassa. Our findings also indicate that DBF-2 is essential for sexual reproduction in a filamentous fungus. Defects in other Hippo and glycogen metabolism pathway components (mob-1, ccr-4, mst-1, and gsk-3) share similar phenotypes such as mitotic delay and decreased CDC-2 (cell division cycle 2) protein levels, massive hyphal swellings, hyphal tip bursting, glycogen leakage, and impaired conidiation. We propose that DBF-2 functions as a link between Hippo and glycogen metabolism pathways.
Collapse
|