1
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Mela AP, Glass NL. Permissiveness and competition within and between Neurospora crassa syncytia. Genetics 2023; 224:iyad112. [PMID: 37313736 PMCID: PMC10411585 DOI: 10.1093/genetics/iyad112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 05/18/2023] [Accepted: 05/19/2023] [Indexed: 06/15/2023] Open
Abstract
A multinucleate syncytium is a common growth form in filamentous fungi. Comprehensive functions of the syncytial state remain unknown, but it likely allows for a wide range of adaptations to enable filamentous fungi to coordinate growth, reproduction, responses to the environment, and to distribute nuclear and cytoplasmic elements across a colony. Indeed, the underlying mechanistic details of how syncytia regulate cellular and molecular processes spatiotemporally across a colony are largely unexplored. Here, we implemented a strategy to analyze the relative fitness of different nuclear populations in syncytia of Neurospora crassa, including nuclei with loss-of-function mutations in essential genes, based on production of multinucleate asexual spores using flow cytometry of pairings between strains with differentially fluorescently tagged nuclear histones. The distribution of homokaryotic and heterokaryotic asexual spores in pairings was assessed between different auxotrophic and morphological mutants, as well as with strains that were defective in somatic cell fusion or were heterokaryon incompatible. Mutant nuclei were compartmentalized into both homokaryotic and heterokaryotic asexual spores, a type of bet hedging for maintenance and evolution of mutational events, despite disadvantages to the syncytium. However, in pairings between strains that were blocked in somatic cell fusion or were heterokaryon incompatible, we observed a "winner-takes-all" phenotype, where asexual spores originating from paired strains were predominantly one genotype. These data indicate that syncytial fungal cells are permissive and tolerate a wide array of nuclear functionality, but that cells/colonies that are unable to cooperate via syncytia formation actively compete for resources.
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Affiliation(s)
- Alexander P Mela
- The Plant and Microbial Biology Department, University of California Berkeley, Berkeley, CA 94720, USA
| | - N Louise Glass
- The Plant and Microbial Biology Department, University of California Berkeley, Berkeley, CA 94720, USA
- The Environmental Genomics and Systems Biology Division, The Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
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2
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Wangsanut T, Amsri A, Pongpom M. Antibody screening reveals antigenic proteins involved in Talaromyces marneffei and human interaction. Front Cell Infect Microbiol 2023; 13:1118979. [PMID: 37404721 PMCID: PMC10315666 DOI: 10.3389/fcimb.2023.1118979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 05/30/2023] [Indexed: 07/06/2023] Open
Abstract
Talaromycosis is a fungal infection that generally affects immunocompromised hosts and is one of the most frequent systemic mycoses in HIV patients, especially in endemic areas such as Southeast Asia. Talaromyces marneffei, the causative agent of talaromycosis, grows as a mold in the environment but adapts to the human body and host niches by transitioning from conidia to yeast-like cells. Knowledge of the human host and T. marneffei interaction has a direct impact on the diagnosis, yet studies are still lacking. The morbidity and mortality rates are high in taloromycosis patients if the diagnosis and treatments are delayed. Immunogenic proteins are excellent candidates for developing detection tools. Previously, we identified antigenic proteins that were recognized by antibodies from talaromycosis sera. Three of these identified proteins have been previously characterized in detail, while the others have not been explored. To expedite the progress of antigen discovery, the complete list of antigenic proteins and their features was fully reported in this study. Functional annotation and Gene Ontology examination revealed that these proteins showed a high association with membrane trafficking. Further bioinformatics analyses were performed to search for antigenic protein characteristics, including functional domains, critical residues, subcellular localization, secretory signals, and epitope peptide sequences. Expression profiling of these antigenic encoding genes was investigated using quantitative real-time PCR. The results demonstrated that most genes were expressed at low levels in the mold form, but were highly upregulated in the pathogenic yeast phase, consistent with the antigenic role of these genes during the human-host interaction. Most transcripts accumulated in the conidia, suggesting a role during phase transition. The collection of all antigen-encoding DNA sequences described here is freely accessible at GenBank, which could be useful for the research community to develop into biomarkers, diagnostic tests, research detection tools, and even vaccines.
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3
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Xin K, Zhang Y, Fan L, Qi Z, Feng C, Wang Q, Jiang C, Xu JR, Liu H. Experimental evidence for the functional importance and adaptive advantage of A-to-I RNA editing in fungi. Proc Natl Acad Sci U S A 2023; 120:e2219029120. [PMID: 36917661 PMCID: PMC10041177 DOI: 10.1073/pnas.2219029120] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 02/13/2023] [Indexed: 03/16/2023] Open
Abstract
Adenosine-to-inosine (A-to-I) editing is the most prevalent type of RNA editing in animals, and it occurs in fungi specifically during sexual reproduction. However, it is debatable whether A-to-I RNA editing is adaptive. Deciphering the functional importance of individual editing sites is essential for the mechanistic understanding of the adaptive advantages of RNA editing. Here, by performing gene deletion for 17 genes with conserved missense editing (CME) sites and engineering underedited (ue) and overedited (oe) mutants for 10 CME sites using site-specific mutagenesis at the native locus in Fusarium graminearum, we demonstrated that two CME sites in CME5 and CME11 genes are functionally important for sexual reproduction. Although the overedited mutant was normal in sexual reproduction, the underedited mutant of CME5 had severe defects in ascus and ascospore formation like the deletion mutant, suggesting that the CME site of CME5 is co-opted for sexual development. The preediting residue of Cme5 is evolutionarily conserved across diverse classes of Ascomycota, while the postediting one is rarely hardwired into the genome, implying that editing at this site leads to higher fitness than a genomic A-to-G mutation. More importantly, mutants expressing only the underedited or the overedited allele of CME11 are defective in ascosporogenesis, while those expressing both alleles displayed normal phenotypes, indicating that concurrently expressing edited and unedited versions of Cme11 is more advantageous than either. Our study provides convincing experimental evidence for the long-suspected adaptive advantages of RNA editing in fungi and likely in animals.
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Affiliation(s)
- Kaiyun Xin
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang, Shaanxi712100, China
| | - Yang Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang, Shaanxi712100, China
| | - Ligang Fan
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang, Shaanxi712100, China
| | - Zhaomei Qi
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang, Shaanxi712100, China
| | - Chanjing Feng
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang, Shaanxi712100, China
| | - Qinhu Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang, Shaanxi712100, China
| | - Cong Jiang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang, Shaanxi712100, China
| | - Jin-Rong Xu
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN47907
| | - Huiquan Liu
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang, Shaanxi712100, China
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4
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Gene complementation strategies for filamentous fungi biotechnology. Process Biochem 2023. [DOI: 10.1016/j.procbio.2023.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
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5
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Ge J, Zhang Z, Li Y, Hu Z, He B, Li Y, Zeng B, Jiang C. Inhibition of AoAur1 increases mycelial growth, hyphal fusion and improves physiological adaptation to high-temperature stress in Aspergillus oryzae. Arch Microbiol 2022; 204:477. [PMID: 35829968 DOI: 10.1007/s00203-022-03075-6] [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: 12/23/2021] [Revised: 06/03/2022] [Accepted: 06/13/2022] [Indexed: 11/02/2022]
Abstract
Inositol phosphorylceramide (IPC) participates in hyphal growth and serves as a signaling molecule that enables fungi to adapt to diverse environments. Here, a gene, encodes IPC synthase, was identified from the Aspergillus oryzae 3.042 genome and designated AoAur1. The characteristics, phylogenetic evolution, and resistance to aureobasidin A of AoAur1 were analyzed. The expression pattern of AoAur1 was markedly downregulated under temperature stress. Additionally, an RNAi-AoAur1 strain in which the AoAur1 expression was inhibited had mycelial that grew more quickly, had a higher frequency of hyphal fusion, and was more resistant to high-temperature stress than the control. Gene expression profiles showed that the genes related to IPC biosynthesis were obviously downregulated, while AoCerS, which participates in dihydroceramide biosynthesis, increased in the RNAi-AoAur1 strain at the three temperature treatments. A metabolomic analysis revealed that the intracellular IPC content decreased, and the accumulation of dihydroceramide and galactosylceramide increased significantly in the RNAi-AoAur1 strain. Thus, the inhibition of AoAur1 reduced IPC level followed by an increase in the contents of dihydroceramide and galactosylceramide that promote mycelial growth and the formation of spores in the RNAi-AoAur1 strain. Interestingly, the inhibition of AoAur1 also induced the expression of hyphal fusion-related genes, which promote hyphal fusion, thus, contributing to the transduction of stress signal to enhance the ability of cells to adapt to temperature stress. Our results demonstrated that the downregulation of AoAur1 and a decrease in the accumulation of IPC is one of the mechanisms that enables A. oryzae to adapt low- and high-temperature stress.
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Affiliation(s)
- Jinxin Ge
- Jiangxi Key Laboratory of Bioprocess Engineering and Co-Innovation Center for In-Vitro Diagnostic Reagents and Devices of Jiangxi Province, College of Life Sciences, Jiangxi Science and Technology Normal University, Nanchang, 330013, China
| | - Zhe Zhang
- Jiangxi Key Laboratory of Bioprocess Engineering and Co-Innovation Center for In-Vitro Diagnostic Reagents and Devices of Jiangxi Province, College of Life Sciences, Jiangxi Science and Technology Normal University, Nanchang, 330013, China
| | - Yuan Li
- Jiangxi Key Laboratory of Bioprocess Engineering and Co-Innovation Center for In-Vitro Diagnostic Reagents and Devices of Jiangxi Province, College of Life Sciences, Jiangxi Science and Technology Normal University, Nanchang, 330013, China
| | - Zhihong Hu
- Jiangxi Key Laboratory of Bioprocess Engineering and Co-Innovation Center for In-Vitro Diagnostic Reagents and Devices of Jiangxi Province, College of Life Sciences, Jiangxi Science and Technology Normal University, Nanchang, 330013, China
| | - Bin He
- Jiangxi Key Laboratory of Bioprocess Engineering and Co-Innovation Center for In-Vitro Diagnostic Reagents and Devices of Jiangxi Province, College of Life Sciences, Jiangxi Science and Technology Normal University, Nanchang, 330013, China
| | - Yongkai Li
- Jiangxi Key Laboratory of Bioprocess Engineering and Co-Innovation Center for In-Vitro Diagnostic Reagents and Devices of Jiangxi Province, College of Life Sciences, Jiangxi Science and Technology Normal University, Nanchang, 330013, China
| | - Bin Zeng
- Jiangxi Key Laboratory of Bioprocess Engineering and Co-Innovation Center for In-Vitro Diagnostic Reagents and Devices of Jiangxi Province, College of Life Sciences, Jiangxi Science and Technology Normal University, Nanchang, 330013, China. .,College of Pharmacy, Shenzhen Technology University, Shenzhen, 518000, China.
| | - Chunmiao Jiang
- Jiangxi Key Laboratory of Bioprocess Engineering and Co-Innovation Center for In-Vitro Diagnostic Reagents and Devices of Jiangxi Province, College of Life Sciences, Jiangxi Science and Technology Normal University, Nanchang, 330013, China.
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6
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Wernet V, Wäckerle J, Fischer R. The STRIPAK component SipC is involved in morphology and cell-fate determination in the nematode-trapping fungus Duddingtonia flagrans. Genetics 2022; 220:iyab153. [PMID: 34849851 PMCID: PMC8733638 DOI: 10.1093/genetics/iyab153] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 08/20/2021] [Indexed: 11/29/2022] Open
Abstract
The striatin-interacting phosphatase and kinase (STRIPAK) complex is a highly conserved eukaryotic signaling hub involved in the regulation of many cellular processes. In filamentous fungi, STRIPAK controls multicellular development, hyphal fusion, septation, and pathogenicity. In this study, we analyzed the role of the STRIPAK complex in the nematode-trapping fungus Duddingtonia flagrans which forms three-dimensional, adhesive trapping networks to capture Caenorhabditis elegans. Trap networks consist of several hyphal loops which are morphologically and functionally different from vegetative hyphae. We show that lack of the STRIPAK component SipC (STRIP1/2/HAM-2/PRO22) results in incomplete loop formation and column-like trap structures with elongated compartments. The misshapen or incomplete traps lost their trap identity and continued growth as vegetative hyphae. The same effect was observed in the presence of the actin cytoskeleton drug cytochalasin A. These results could suggest a link between actin and STRIPAK complex functions.
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Affiliation(s)
- Valentin Wernet
- Department of Microbiology, Institute for Applied Biosciences, Karlsruhe Institute of Technology (KIT)—South Campus, D-76131 Karlsruhe, Germany
| | - Jan Wäckerle
- Department of Microbiology, Institute for Applied Biosciences, Karlsruhe Institute of Technology (KIT)—South Campus, D-76131 Karlsruhe, Germany
| | - Reinhard Fischer
- Department of Microbiology, Institute for Applied Biosciences, Karlsruhe Institute of Technology (KIT)—South Campus, D-76131 Karlsruhe, Germany
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7
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Wilson AM, Wilken PM, Wingfield MJ, Wingfield BD. Genetic Networks That Govern Sexual Reproduction in the Pezizomycotina. Microbiol Mol Biol Rev 2021; 85:e0002021. [PMID: 34585983 PMCID: PMC8485983 DOI: 10.1128/mmbr.00020-21] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Sexual development in filamentous fungi is a complex process that relies on the precise control of and interaction between a variety of genetic networks and pathways. The mating-type (MAT) genes are the master regulators of this process and typically act as transcription factors, which control the expression of genes involved at all stages of the sexual cycle. In many fungi, the sexual cycle typically begins when the mating pheromones of one mating type are recognized by a compatible partner, followed by physical interaction and fertilization. Subsequently, highly specialized sexual structures are formed, within which the sexual spores develop after rounds of meiosis and mitosis. These spores are then released and germinate, forming new individuals that initiate new cycles of growth. This review provides an overview of the known genetic networks and pathways that are involved in each major stage of the sexual cycle in filamentous ascomycete fungi.
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Affiliation(s)
- Andi M. Wilson
- Forestry and Agricultural Biotechnology Institute, Department of Biochemistry, Genetics, and Microbiology, University of Pretoria, Pretoria, Gauteng, South Africa
| | - P. Markus Wilken
- Forestry and Agricultural Biotechnology Institute, Department of Biochemistry, Genetics, and Microbiology, University of Pretoria, Pretoria, Gauteng, South Africa
| | - Michael J. Wingfield
- Forestry and Agricultural Biotechnology Institute, Department of Biochemistry, Genetics, and Microbiology, University of Pretoria, Pretoria, Gauteng, South Africa
| | - Brenda D. Wingfield
- Forestry and Agricultural Biotechnology Institute, Department of Biochemistry, Genetics, and Microbiology, University of Pretoria, Pretoria, Gauteng, South Africa
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8
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Šečić E, Zanini S, Wibberg D, Jelonek L, Busche T, Kalinowski J, Nasfi S, Thielmann J, Imani J, Steinbrenner J, Kogel KH. A novel plant-fungal association reveals fundamental sRNA and gene expression reprogramming at the onset of symbiosis. BMC Biol 2021; 19:171. [PMID: 34429124 PMCID: PMC8385953 DOI: 10.1186/s12915-021-01104-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 07/16/2021] [Indexed: 01/15/2023] Open
Affiliation(s)
- Ena Šečić
- Institute of Phytopathology, Centre for BioSystems, Land Use and Nutrition, Justus Liebig University, 35392, Giessen, Germany
| | - Silvia Zanini
- Institute of Phytopathology, Centre for BioSystems, Land Use and Nutrition, Justus Liebig University, 35392, Giessen, Germany
| | - Daniel Wibberg
- Center for Biotechnology - CeBiTec, Bielefeld University, 33615, Bielefeld, Germany
| | - Lukas Jelonek
- Institute of Bioinformatics and Systems Biology, Justus Liebig University, 35392, Giessen, Germany
| | - Tobias Busche
- Center for Biotechnology - CeBiTec, Bielefeld University, 33615, Bielefeld, Germany
| | - Jörn Kalinowski
- Center for Biotechnology - CeBiTec, Bielefeld University, 33615, Bielefeld, Germany
| | - Sabrine Nasfi
- Institute of Phytopathology, Centre for BioSystems, Land Use and Nutrition, Justus Liebig University, 35392, Giessen, Germany
| | - Jennifer Thielmann
- Institute of Phytopathology, Centre for BioSystems, Land Use and Nutrition, Justus Liebig University, 35392, Giessen, Germany
| | - Jafargholi Imani
- Institute of Phytopathology, Centre for BioSystems, Land Use and Nutrition, Justus Liebig University, 35392, Giessen, Germany
| | - Jens Steinbrenner
- Institute of Phytopathology, Centre for BioSystems, Land Use and Nutrition, Justus Liebig University, 35392, Giessen, Germany
| | - Karl-Heinz Kogel
- Institute of Phytopathology, Centre for BioSystems, Land Use and Nutrition, Justus Liebig University, 35392, Giessen, Germany.
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9
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STRIPAK, a Key Regulator of Fungal Development, Operates as a Multifunctional Signaling Hub. J Fungi (Basel) 2021; 7:jof7060443. [PMID: 34206073 PMCID: PMC8226480 DOI: 10.3390/jof7060443] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 05/26/2021] [Accepted: 05/29/2021] [Indexed: 01/26/2023] Open
Abstract
The striatin-interacting phosphatases and kinases (STRIPAK) multi subunit complex is a highly conserved signaling complex that controls diverse developmental processes in higher and lower eukaryotes. In this perspective article, we summarize how STRIPAK controls diverse developmental processes in euascomycetes, such as fruiting body formation, cell fusion, sexual and vegetative development, pathogenicity, symbiosis, as well as secondary metabolism. Recent structural investigations revealed information about the assembly and stoichiometry of the complex enabling it to act as a signaling hub. Multiple organellar targeting of STRIPAK subunits suggests how this complex connects several signaling transduction pathways involved in diverse cellular developmental processes. Furthermore, recent phosphoproteomic analysis shows that STRIPAK controls the dephosphorylation of subunits from several signaling complexes. We also refer to recent findings in yeast, where the STRIPAK homologue connects conserved signaling pathways, and based on this we suggest how so far non-characterized proteins may functions as receptors connecting mitophagy with the STRIPAK signaling complex. Such lines of investigation should contribute to the overall mechanistic understanding of how STRIPAK controls development in euascomycetes and beyond.
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10
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Zhang S, Dong Y, Qiang R, Zhang Y, Zhang X, Chen Y, Jiang P, Ma X, Wu L, Ai J, Gao X, Wang P, Chen J, Chai R. Characterization of Strip1 Expression in Mouse Cochlear Hair Cells. Front Genet 2021; 12:625867. [PMID: 33889175 PMCID: PMC8056008 DOI: 10.3389/fgene.2021.625867] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 03/12/2021] [Indexed: 12/13/2022] Open
Abstract
Striatin-interacting protein 1 (Strip1) is a core component of the striatin interacting phosphatase and kinase (STRIPAK) complex, which is involved in embryogenesis and development, circadian rhythms, type 2 diabetes, and cancer progression. However, the expression and role of Strip1 in the mammalian cochlea remains unclear. Here we studied the expression and function of Strip1 in the mouse cochlea by using Strip1 knockout mice. We first found that the mRNA and protein expression of Strip1 increases as mice age starting from postnatal day (P) 3 and reaches its highest expression level at P30 and that the expression of Strip1 can be detected by immunofluorescent staining starting from P14 only in cochlear HCs, and not in supporting cells (SCs). Next, we crossed Strip1 heterozygous knockout (Strip +/−) mice to obtain Strip1 homozygous knockout (Strip1−/−) mice for studying the role of Strip1 in cochlear HCs. However, no Strip1−/− mice were obtained and the ratio of Strip +/− to Strip1+/+ mice per litter was about 2:1, which suggested that homozygous Strip1 knockout is embryonic lethal. We measured hearing function and counted the HC number in P30 and P60 Strip +/− mice and found that they had normal hearing ability and HC numbers compared to Strip1+/+ mice. Our study suggested that Strip1 probably play important roles in HC development and maturation, which needs further study in the future.
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Affiliation(s)
- Shasha Zhang
- State Key Laboratory of Bioelectronics, School of Life Sciences and Technology, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
| | - Ying Dong
- State Key Laboratory of Bioelectronics, School of Life Sciences and Technology, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
| | - Ruiying Qiang
- State Key Laboratory of Bioelectronics, School of Life Sciences and Technology, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
| | - Yuan Zhang
- State Key Laboratory of Bioelectronics, School of Life Sciences and Technology, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
| | - Xiaoli Zhang
- Jiangsu Provincial Key Medical Discipline (Laboratory), Department of Otolaryngology Head and Neck Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Yin Chen
- Jiangsu Provincial Key Medical Discipline (Laboratory), Department of Otolaryngology Head and Neck Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Pei Jiang
- State Key Laboratory of Bioelectronics, School of Life Sciences and Technology, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
| | - Xiangyu Ma
- State Key Laboratory of Bioelectronics, School of Life Sciences and Technology, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
| | - Leilei Wu
- State Key Laboratory of Bioelectronics, School of Life Sciences and Technology, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
| | - Jingru Ai
- State Key Laboratory of Bioelectronics, School of Life Sciences and Technology, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
| | - Xia Gao
- Jiangsu Provincial Key Medical Discipline (Laboratory), Department of Otolaryngology Head and Neck Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Pengjun Wang
- Department of Otorhinolaryngology, Affiliated Sixth People's Hospital of Shanghai Jiao Tong University, Shanghai, China
| | - Jie Chen
- Jiangsu Provincial Key Medical Discipline (Laboratory), Department of Otolaryngology Head and Neck Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Renjie Chai
- State Key Laboratory of Bioelectronics, School of Life Sciences and Technology, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China.,Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China.,Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China.,Beijing Key Laboratory of Neural Regeneration and Repair, Capital Medical University, Beijing, China
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11
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Rodriguez-Cupello C, Dam M, Serini L, Wang S, Lindgren D, Englund E, Kjellman P, Axelson H, García-Mariscal A, Madsen CD. The STRIPAK Complex Regulates Response to Chemotherapy Through p21 and p27. Front Cell Dev Biol 2020; 8:146. [PMID: 32258031 PMCID: PMC7089963 DOI: 10.3389/fcell.2020.00146] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 02/21/2020] [Indexed: 12/18/2022] Open
Abstract
The STRIPAK complex has been linked to a variety of biological processes taking place during embryogenesis and development, but its role in cancer has only just started to be defined. Here, we expand on previous work indicating a role for the scaffolding protein STRIP1 in cancer cell migration and metastasis. We show that cell cycle arrest and decreased proliferation are seen upon loss of STRIP1 in MDA-MB-231 cells due to the induction of cyclin dependent kinase inhibitors, including p21 and p27. We demonstrate that p21 and p27 induction is observed in a subpopulation of cells having low DNA damage response and that the p21high/γH2AXlow ratio within single cells can be rescued by depleting MST3&4 kinases. While the loss of STRIP1 decreases cell proliferation and tumor growth, cells treated with low dosage of chemotherapeutics in vitro paradoxically escape therapy-induced senescence and begin to proliferate after recovery. This corroborates with already known research on the dual role of p21 and indicates that STRIP1 also plays a contradictory role in breast cancer, suppressing tumor growth, but once treated with chemotherapeutics, allowing for possible recurrence and decreased patient survival.
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Affiliation(s)
- Carmen Rodriguez-Cupello
- Division of Translational Cancer Research, Department of Laboratory Medicine, Lund University, Lund, Sweden
| | - Monica Dam
- Division of Translational Cancer Research, Department of Laboratory Medicine, Lund University, Lund, Sweden
| | - Laura Serini
- Division of Translational Cancer Research, Department of Laboratory Medicine, Lund University, Lund, Sweden
| | - Shan Wang
- Division of Translational Cancer Research, Department of Laboratory Medicine, Lund University, Lund, Sweden
| | - David Lindgren
- Division of Translational Cancer Research, Department of Laboratory Medicine, Lund University, Lund, Sweden
| | - Emelie Englund
- Division of Translational Cancer Research, Department of Laboratory Medicine, Lund University, Lund, Sweden
| | - Pontus Kjellman
- Division of Translational Cancer Research, Department of Laboratory Medicine, Lund University, Lund, Sweden
| | - Håkan Axelson
- Division of Translational Cancer Research, Department of Laboratory Medicine, Lund University, Lund, Sweden
| | - Alberto García-Mariscal
- Division of Translational Cancer Research, Department of Laboratory Medicine, Lund University, Lund, Sweden
| | - Chris D Madsen
- Division of Translational Cancer Research, Department of Laboratory Medicine, Lund University, Lund, Sweden
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12
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Schumann MR, Brandt U, Adis C, Hartung L, Fleißner A. Plasma Membrane Integrity During Cell-Cell Fusion and in Response to Pore-Forming Drugs Is Promoted by the Penta-EF-Hand Protein PEF1 in Neurospora crassa. Genetics 2019; 213:195-211. [PMID: 31270133 PMCID: PMC6727798 DOI: 10.1534/genetics.119.302363] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 06/14/2019] [Indexed: 12/20/2022] Open
Abstract
Plasma membrane damage commonly occurs during cellular growth and development. To counteract these potentially lethal injuries, membrane repair mechanisms have evolved, which promote the integrity of the lipid bilayer. Although the membrane of fungi is the target of important clinical drugs and agricultural fungicides, the molecular mechanisms which mediate membrane repair in these organisms remain elusive. Here we identify the penta-EF-hand protein PEF1 of the genetic model fungus Neurospora crassa as part of a cellular response mechanism against different types of membrane injury. Deletion of the pef1 gene in the wild type and different lysis-prone gene knockout mutants revealed a function of the protein in maintaining cell integrity during cell-cell fusion and in the presence of pore-forming drugs, such as the plant defense compound tomatine. By fluorescence and live-cell imaging we show that green fluorescent protein (GFP)-tagged PEF1 accumulates at the sites of membrane injury in a Ca2+-dependent manner. Site-directed mutagenesis identified Ca2+-binding domains essential for the spatial dynamics and function of the protein. In addition, the subcellular localization of PEF1 revealed that the syncytial fungal colony undergoes compartmentation in response to antifungal treatment. We propose that plasma membrane repair in fungi constitutes an additional line of defense against membrane-disturbing drugs, thereby expanding the current model of fungal drug resistance mechanisms.
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Affiliation(s)
| | - Ulrike Brandt
- Institut für Genetik, Technische Universität Braunschweig, 38106, Germany
| | - Christian Adis
- Institut für Genetik, Technische Universität Braunschweig, 38106, Germany
| | - Lisa Hartung
- Institut für Genetik, Technische Universität Braunschweig, 38106, Germany
| | - André Fleißner
- Institut für Genetik, Technische Universität Braunschweig, 38106, Germany
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13
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Kück U, Radchenko D, Teichert I. STRIPAK, a highly conserved signaling complex, controls multiple eukaryotic cellular and developmental processes and is linked with human diseases. Biol Chem 2019; 400:1005-1022. [PMID: 31042639 DOI: 10.1515/hsz-2019-0173] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 03/28/2019] [Indexed: 01/17/2023]
Abstract
The striatin-interacting phosphatases and kinases (STRIPAK) complex is evolutionary highly conserved and has been structurally and functionally described in diverse lower and higher eukaryotes. In recent years, this complex has been biochemically characterized better and further analyses in different model systems have shown that it is also involved in numerous cellular and developmental processes in eukaryotic organisms. Further recent results have shown that the STRIPAK complex functions as a macromolecular assembly communicating through physical interaction with other conserved signaling protein complexes to constitute larger dynamic protein networks. Here, we will provide a comprehensive and up-to-date overview of the architecture, function and regulation of the STRIPAK complex and discuss key issues and future perspectives, linked with human diseases, which may form the basis of further research endeavors in this area. In particular, the investigation of bi-directional interactions between STRIPAK and other signaling pathways should elucidate upstream regulators and downstream targets as fundamental parts of a complex cellular network.
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Affiliation(s)
- Ulrich Kück
- Allgemeine und Molekulare Botanik, Ruhr-Universität Bochum, Universitätsstr. 150, D-44780 Bochum, Germany
| | - Daria Radchenko
- Allgemeine und Molekulare Botanik, Ruhr-Universität Bochum, Universitätsstr. 150, D-44780 Bochum, Germany
| | - Ines Teichert
- Allgemeine und Molekulare Botanik, Ruhr-Universität Bochum, Universitätsstr. 150, D-44780 Bochum, Germany
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14
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J Reschka E, Nordzieke S, Valerius O, Braus GH, Pöggeler S. A novel STRIPAK complex component mediates hyphal fusion and fruiting-body development in filamentous fungi. Mol Microbiol 2018; 110:513-532. [PMID: 30107058 DOI: 10.1111/mmi.14106] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/12/2018] [Indexed: 01/17/2023]
Abstract
The STRIPAK complex is involved in growth, cell fusion, development and signaling pathways, and thus malfunctions in the human STRIPAK complex often result in severe neuronal diseases and cancer. Despite the high degree of general conservation throughout the complex, several STRIPAK complex-associated small coiled-coil proteins of animals and yeasts are not conserved across species. As there are no data for filamentous ascomycetes, we addressed this through affinity purification with HA-tagged striatin ortholog PRO11 in Sordaria macrospora. Combining the method with liquid chromatography-mass spectrometry, we were able to co-purify STRIPAK complex interactor 1 (SCI1), the first STRIPAK-associated small coiled-coil protein in filamentous ascomycetes. Using yeast two-hybrid experiments, we identified SCI1 protein regions required for SCI1-PRO11 interaction, dimerization of SCI1 and interaction with other STRIPAK components. Further, both proteins PRO11 and SCI1 co-localize with the nuclear basket protein SmPOM152 at the nuclear envelope. Expression of the gene sci1 occurs during early developmental stages of S. macrospora, and the protein SCI1 in combination with PRO11 is required for cell fusion, vegetative growth and sexual development. The results of the present study will help to understand the underlying molecular mechanisms of STRIPAK signaling and function in cellular development and diseases in higher eukaryotes.
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Affiliation(s)
- Eva J Reschka
- Institute of Microbiology and Genetics, Department of Genetics of Eukaryotic Microorganisms, Georg-August University, Göttingen, Germany
| | - Steffen Nordzieke
- Institute of Microbiology and Genetics, Department of Genetics of Eukaryotic Microorganisms, Georg-August University, Göttingen, Germany
| | - Oliver Valerius
- Institute of Microbiology and Genetics, Department of Molecular Microbiology & Genetics, Georg-August University, Göttingen, Germany.,Göttingen Center for Molecular Biosciences (GZMB), Georg-August University, Göttingen, Germany
| | - Gerhard H Braus
- Institute of Microbiology and Genetics, Department of Molecular Microbiology & Genetics, Georg-August University, Göttingen, Germany.,Göttingen Center for Molecular Biosciences (GZMB), Georg-August University, Göttingen, Germany
| | - Stefanie Pöggeler
- Institute of Microbiology and Genetics, Department of Genetics of Eukaryotic Microorganisms, Georg-August University, Göttingen, Germany.,Göttingen Center for Molecular Biosciences (GZMB), Georg-August University, Göttingen, Germany
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15
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Li D, Musante V, Zhou W, Picciotto MR, Nairn AC. Striatin-1 is a B subunit of protein phosphatase PP2A that regulates dendritic arborization and spine development in striatal neurons. J Biol Chem 2018; 293:11179-11194. [PMID: 29802198 DOI: 10.1074/jbc.ra117.001519] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 05/06/2018] [Indexed: 01/09/2023] Open
Abstract
Striatin-1, a subunit of the serine/threonine phosphatase PP2A, is preferentially expressed in neurons in the striatum. As a member of the striatin family of B subunits, striatin-1 is a core component together with PP2A of a multiprotein complex called STRIPAK, the striatin-interacting phosphatase and kinase complex. Little is known about the function of striatin-1 or the STRIPAK complex in the mammalian striatum. Here, we identify a selective role for striatin-1 in striatal neuron maturation. Using a small hairpin RNA (shRNA) knockdown approach in primary striatal neuronal cultures, we determined that reduced expression of striatin-1 results in increased dendritic complexity and an increased density of dendritic spines, classified as stubby spines. The dendritic phenotype was rescued by co-expression of a striatin-1 mutant construct insensitive to the knockdown shRNA but was not rescued by co-expression of PP2A- or Mob3-binding deficient striatin-1 constructs. Reduction of striatin-1 did not result in deficits in neuronal connectivity in this knockdown model, as we observed no abnormalities in synapse formation or in spontaneous excitatory postsynaptic currents. Thus, this study suggests that striatin-1 is a regulator of neuronal development in striatal neurons.
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Affiliation(s)
- Daniel Li
- From the Department of Psychiatry, Yale University, New Haven, Connecticut 06520
| | - Veronica Musante
- From the Department of Psychiatry, Yale University, New Haven, Connecticut 06520
| | - Wenliang Zhou
- From the Department of Psychiatry, Yale University, New Haven, Connecticut 06520
| | - Marina R Picciotto
- From the Department of Psychiatry, Yale University, New Haven, Connecticut 06520
| | - Angus C Nairn
- From the Department of Psychiatry, Yale University, New Haven, Connecticut 06520
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16
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Zhang H, Mukherjee M, Kim J, Yu W, Shim W. Fsr1, a striatin homologue, forms an endomembrane-associated complex that regulates virulence in the maize pathogen Fusarium verticillioides. MOLECULAR PLANT PATHOLOGY 2018; 19:812-826. [PMID: 28467007 PMCID: PMC6638083 DOI: 10.1111/mpp.12562] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 04/06/2017] [Indexed: 05/09/2023]
Abstract
Fsr1, a homologue of mammalian striatin, containing multiple protein-binding domains and a coiled-coil (CC) domain, is critical for Fusarium verticillioides virulence. In mammals, striatin interacts with multiple proteins to form a STRIPAK (striatin-interacting phosphatase and kinase) complex that regulates a variety of developmental processes and cellular mechanisms. In this study, we identified the homologue of a key mammalian STRIPAK component STRIP1/2 (striatin-interacting proteins 1 and 2) in F. verticillioides, FvStp1, which interacts with Fsr1 in vivo. Gene deletion analysis indicates that FvStp1 is critical for F. verticillioides stalk rot virulence. In addition, we identified three proteins, designated FvCyp1, FvScp1 and FvSel1, which interact with the Fsr1 CC domain via a yeast two-hybrid screen. Importantly, FvCyp1, FvScp1 and FvSel1 co-localize to endomembrane structures, each having a preferred localization in the cell, and they are all required for F. verticillioides stalk rot virulence. Moreover, these proteins are necessary for the correct localization of Fsr1 to the endoplasmic reticulum (ER) and nuclear envelope. Thus, we identified several novel components in the STRIPAK complex that regulates F. verticillioides virulence, and propose that the correct organization and localization of Fsr1 are critical for STRIPAK complex function.
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Affiliation(s)
- Huan Zhang
- Department of Plant Pathology & MicrobiologyTexas A&M University, College StationTX 77843‐2132USA
| | - Mala Mukherjee
- Department of Plant Pathology & MicrobiologyTexas A&M University, College StationTX 77843‐2132USA
| | - Jung‐Eun Kim
- Department of Plant Pathology & MicrobiologyTexas A&M University, College StationTX 77843‐2132USA
| | - Wenying Yu
- College of Life Science, Fujian Agricultural and Forestry UniversityFuzhou 350002China
| | - Won‐Bo Shim
- Department of Plant Pathology & MicrobiologyTexas A&M University, College StationTX 77843‐2132USA
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17
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BiFC-based visualisation system reveals cell fusion morphology and heterokaryon incompatibility in the filamentous fungus Aspergillus oryzae. Sci Rep 2018; 8:2922. [PMID: 29440689 PMCID: PMC5811552 DOI: 10.1038/s41598-018-21323-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 02/01/2018] [Indexed: 12/13/2022] Open
Abstract
Aspergillus oryzae is an industrially important filamentous fungus used for Japanese traditional food fermentation and heterologous protein production. Although cell fusion is important for heterokaryon formation and sexual/parasexual reproduction required for cross breeding, knowledge on cell fusion and heterokaryon incompatibility in A. oryzae is limited because of low cell fusion frequency. Therefore, we aimed to develop a BiFC system to specifically visualise fused cells and facilitate the analysis of cell fusion in A. oryzae. The cell fusion ability and morphology of 15 A. oryzae strains were investigated using heterodimerising proteins LZA and LZB fused with split green fluorescence protein. Morphological investigation of fused cells revealed that cell fusion occurred mainly as conidial anastomosis during the early growth stage. Self-fusion abilities were detected in most industrial A. oryzae strains, but only a few strain pairs showed non-self fusion. Protoplast fusion assay demonstrated that almost all the pairs capable of non-self fusion were capable of heterokaryon formation and vice versa, thus providing the first evidence of heterokaryon incompatibility in A. oryzae. The BiFC system developed in this study provides an effective method in studying morphology of fused cells and heterokaryon incompatibility in the filamentous fungal species with low cell fusion efficiency.
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18
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STRIP1, a core component of STRIPAK complexes, is essential for normal mesoderm migration in the mouse embryo. Proc Natl Acad Sci U S A 2017; 114:E10928-E10936. [PMID: 29203676 PMCID: PMC5754794 DOI: 10.1073/pnas.1713535114] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Striatin-interacting phosphatases and kinases (STRIPAK) complexes can regulate the cytoskeleton and cell migration in cell lines, but their roles in vivo in mammals are not known. Here, we show that mouse embryos that lack striatin-interacting protein 1 (STRIP1), a core component of STRIPAK complexes, arrest at midgestation with striking morphological defects. Strip1 mutants lack a trunk, and both paraxial and axial mesoderm fail to elongate along the anterior–posterior body axis. Mesodermal cells from Strip1 mutants have defects in actin organization, focal adhesions, and cell migration that can account for the failure of normal mesoderm migration. The findings demonstrate that STRIPAK is a critical regulator of mammalian cell migration and is likely to have important roles in tumor progression as well as development. Regulated mesoderm migration is necessary for the proper morphogenesis and organ formation during embryonic development. Cell migration and its dependence on the cytoskeleton and signaling machines have been studied extensively in cultured cells; in contrast, remarkably little is known about the mechanisms that regulate mesoderm cell migration in vivo. Here, we report the identification and characterization of a mouse mutation in striatin-interacting protein 1 (Strip1) that disrupts migration of the mesoderm after the gastrulation epithelial-to-mesenchymal transition (EMT). STRIP1 is a core component of the biochemically defined mammalian striatin-interacting phosphatases and kinase (STRIPAK) complexes that appear to act through regulation of protein phosphatase 2A (PP2A), but their functions in mammals in vivo have not been examined. Strip1-null mutants arrest development at midgestation with profound disruptions in the organization of the mesoderm and its derivatives, including a complete failure of the anterior extension of axial mesoderm. Analysis of cultured mesoderm explants and mouse embryonic fibroblasts from null mutants shows that the mesoderm migration defect is correlated with decreased cell spreading, abnormal focal adhesions, changes in the organization of the actin cytoskeleton, and decreased velocity of cell migration. The results show that STRIPAK complexes are essential for cell migration and tissue morphogenesis in vivo.
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19
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Zhao X, Spraker JE, Bok JW, Velk T, He ZM, Keller NP. A Cellular Fusion Cascade Regulated by LaeA Is Required for Sclerotial Development in Aspergillus flavus. Front Microbiol 2017; 8:1925. [PMID: 29051754 PMCID: PMC5633613 DOI: 10.3389/fmicb.2017.01925] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 09/21/2017] [Indexed: 11/13/2022] Open
Abstract
Aspergillus flavus is a saprophytic soil fungus that poses a serious threat worldwide as it contaminates many food and feed crops with the carcinogenic mycotoxin called aflatoxin. This pathogen persists as sclerotia in the soil which enables fungal survival in harsh environmental conditions. Sclerotia formation by A. flavus depends on successful cell communication and hyphal fusion events. Loss of LaeA, a conserved developmental regulator in fungi, abolishes sclerotia formation in this species whereas overexpression (OE) of laeA results in enhanced sclerotia production. Here we demonstrate that sclerotia loss and inability to form heterokaryons in A. flavusΔlaeA is mediated by homologs of the Neurospora crassa ham (hyphal anastomosis) genes termed hamE-I in A. flavus. LaeA positively regulates ham gene expression and deletion of hamF, G, H, or I phenocopies ΔlaeA as demonstrated by heterokaryon and sclerotia loss and reduced aflatoxin synthesis and virulence of these mutants. Deletion of hamE showed a less severe phenotype. hamE-I homologs are positively regulated by the clock controlled transcription factor ADV-1 in N. crassa. Similarly, the ADV-1 homolog NosA regulates hamE-I expression in A. flavus, is required for sclerotial development and is itself positively regulated by LaeA. We speculate that a putative LaeA>NosA>fusion cascade underlies the previously described circadian clock regulation of sclerotia production in A. flavus.
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Affiliation(s)
- Xixi Zhao
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, United States
| | - Joseph E Spraker
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI, United States
| | - Jin Woo Bok
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, United States
| | - Thomas Velk
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, United States
| | - Zhu-Mei He
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Nancy P Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, United States.,Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, United States
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20
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A-to-I RNA editing is developmentally regulated and generally adaptive for sexual reproduction in Neurospora crassa. Proc Natl Acad Sci U S A 2017; 114:E7756-E7765. [PMID: 28847945 DOI: 10.1073/pnas.1702591114] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Although fungi lack adenosine deaminase acting on RNA (ADAR) enzymes, adenosine to inosine (A-to-I) RNA editing was reported recently in Fusarium graminearum during sexual reproduction. In this study, we profiled the A-to-I editing landscape and characterized its functional and adaptive properties in the model filamentous fungus Neurospora crassa A total of 40,677 A-to-I editing sites were identified, and approximately half of them displayed stage-specific editing or editing levels at different sexual stages. RNA-sequencing analysis with the Δstc-1 and Δsad-1 mutants confirmed A-to-I editing occurred before ascus development but became more prevalent during ascosporogenesis. Besides fungal-specific sequence and secondary structure preference, 63.5% of A-to-I editing sites were in the coding regions and 81.3% of them resulted in nonsynonymous recoding, resulting in a significant increase in the proteome complexity. Many genes involved in RNA silencing, DNA methylation, and histone modifications had extensive recoding, including sad-1, sms-3, qde-1, and dim-2. Fifty pseudogenes harbor premature stop codons that require A-to-I editing to encode full-length proteins. Unlike in humans, nonsynonymous editing events in N. crassa are generally beneficial and favored by positive selection. Almost half of the nonsynonymous editing sites in N. crassa are conserved and edited in Neurospora tetrasperma Furthermore, hundreds of them are conserved in F. graminearum and had higher editing levels. Two unknown genes with editing sites conserved between Neurospora and Fusarium were experimentally shown to be important for ascosporogenesis. This study comprehensively analyzed A-to-I editing in N. crassa and showed that RNA editing is stage-specific and generally adaptive, and may be functionally related to repeat induced point mutation and meiotic silencing by unpaired DNA.
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21
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Dekhang R, Wu C, Smith KM, Lamb TM, Peterson M, Bredeweg EL, Ibarra O, Emerson JM, Karunarathna N, Lyubetskaya A, Azizi E, Hurley JM, Dunlap JC, Galagan JE, Freitag M, Sachs MS, Bell-Pedersen D. The Neurospora Transcription Factor ADV-1 Transduces Light Signals and Temporal Information to Control Rhythmic Expression of Genes Involved in Cell Fusion. G3 (BETHESDA, MD.) 2017; 7:129-142. [PMID: 27856696 PMCID: PMC5217103 DOI: 10.1534/g3.116.034298] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 11/01/2016] [Indexed: 12/20/2022]
Abstract
Light and the circadian clock have a profound effect on the biology of organisms through the regulation of large sets of genes. Toward understanding how light and the circadian clock regulate gene expression, we used genome-wide approaches to identify the direct and indirect targets of the light-responsive and clock-controlled transcription factor ADV-1 in Neurospora crassa A large proportion of ADV-1 targets were found to be light- and/or clock-controlled, and enriched for genes involved in development, metabolism, cell growth, and cell fusion. We show that ADV-1 is necessary for transducing light and/or temporal information to its immediate downstream targets, including controlling rhythms in genes critical to somatic cell fusion. However, while ADV-1 targets are altered in predictable ways in Δadv-1 cells in response to light, this is not always the case for rhythmic target gene expression. These data suggest that a complex regulatory network downstream of ADV-1 functions to generate distinct temporal dynamics of target gene expression relative to the central clock mechanism.
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Affiliation(s)
- Rigzin Dekhang
- Department of Biology, Texas A&M University, College Station, Texas 77843
| | - Cheng Wu
- Department of Biology, Texas A&M University, College Station, Texas 77843
| | - Kristina M Smith
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331
| | - Teresa M Lamb
- Department of Biology, Texas A&M University, College Station, Texas 77843
| | | | - Erin L Bredeweg
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331
| | - Oneida Ibarra
- Department of Biology, Texas A&M University, College Station, Texas 77843
| | - Jillian M Emerson
- Department of Genetics, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755
| | | | | | - Elham Azizi
- Bioinformatics Program, Boston University, Massachusetts 02215
| | - Jennifer M Hurley
- Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, New York 12180
| | - Jay C Dunlap
- Department of Genetics, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755
| | - James E Galagan
- Bioinformatics Program, Boston University, Massachusetts 02215
- National Emerging Infectious Diseases Laboratories, Boston University, Massachusetts 02118
- Department of Microbiology, Boston University, Massachusetts 02215
- Department of Biomedical Engineering, Boston University, Massachusetts 02215
| | - Michael Freitag
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331
| | - Matthew S Sachs
- Department of Biology, Texas A&M University, College Station, Texas 77843
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22
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Steffens EK, Becker K, Krevet S, Teichert I, Kück U. Transcription factor PRO1 targets genes encoding conserved components of fungal developmental signaling pathways. Mol Microbiol 2016; 102:792-809. [PMID: 27560538 DOI: 10.1111/mmi.13491] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/24/2016] [Indexed: 01/05/2023]
Abstract
The filamentous fungus Sordaria macrospora is a model system to study multicellular development during fruiting body formation. Previously, we demonstrated that this major process in the sexual life cycle is controlled by the Zn(II)2 Cys6 zinc cluster transcription factor PRO1. Here, we further investigated the genome-wide regulatory network controlled by PRO1 by employing chromatin immunoprecipitation combined with next-generation sequencing (ChIP-seq) to identify binding sites for PRO1. We identified several target regions that occur in the promoter regions of genes encoding components of diverse signaling pathways. Furthermore, we identified a conserved DNA-binding motif that is bound specifically by PRO1 in vitro. In addition, PRO1 controls in vivo the expression of a DsRed reporter gene under the control of the esdC target gene promoter. Our ChIP-seq data suggest that PRO1 also controls target genes previously shown to be involved in regulating the pathways controlling cell wall integrity, NADPH oxidase and pheromone signaling. Our data point to PRO1 acting as a master regulator of genes for signaling components that comprise a developmental cascade controlling fruiting body formation.
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Affiliation(s)
- Eva Katharina Steffens
- Lehrstuhl für Allgemeine und Molekulare Botanik Ruhr-University Bochum, Universitätsstraße 150, Bochum, 44780, Germany
| | - Kordula Becker
- Lehrstuhl für Allgemeine und Molekulare Botanik Ruhr-University Bochum, Universitätsstraße 150, Bochum, 44780, Germany
| | - Sabine Krevet
- Lehrstuhl für Allgemeine und Molekulare Botanik Ruhr-University Bochum, Universitätsstraße 150, Bochum, 44780, Germany
| | - Ines Teichert
- Lehrstuhl für Allgemeine und Molekulare Botanik Ruhr-University Bochum, Universitätsstraße 150, Bochum, 44780, Germany
| | - Ulrich Kück
- Lehrstuhl für Allgemeine und Molekulare Botanik Ruhr-University Bochum, Universitätsstraße 150, Bochum, 44780, Germany
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23
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Turrà D, Nordzieke D, Vitale S, El Ghalid M, Di Pietro A. Hyphal chemotropism in fungal pathogenicity. Semin Cell Dev Biol 2016; 57:69-75. [PMID: 27150623 DOI: 10.1016/j.semcdb.2016.04.020] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 04/29/2016] [Accepted: 04/29/2016] [Indexed: 10/21/2022]
Abstract
The ability to grow as filamentous hyphae defines the lifestyle of fungi. Hyphae are exposed to a variety of chemical stimuli such as nutrients or signal molecules from mating partners and host organisms. How fungi sense and process this chemical information to steer hyphal growth is poorly understood. Saccharomyces cerevisiae and Neurospora crassa have served as genetic models for the identification of cellular components functioning in chemotropism. A recent study in the pathogen Fusarium oxysporum revealed distinct MAPK pathways governing hyphal growth towards nutrient sources and sex pheromones or plant signals, suggesting an unanticipated complexity of chemosensing during fungus-host interactions.
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Affiliation(s)
- David Turrà
- Departamento de Genética, Campus de Excelencia Internacional Agroalimentario ceiA3, Universidad de Córdoba, 14071 Córdoba, Spain
| | - Daniela Nordzieke
- Departamento de Genética, Campus de Excelencia Internacional Agroalimentario ceiA3, Universidad de Córdoba, 14071 Córdoba, Spain
| | - Stefania Vitale
- Departamento de Genética, Campus de Excelencia Internacional Agroalimentario ceiA3, Universidad de Córdoba, 14071 Córdoba, Spain
| | - Mennat El Ghalid
- Departamento de Genética, Campus de Excelencia Internacional Agroalimentario ceiA3, Universidad de Córdoba, 14071 Córdoba, Spain
| | - Antonio Di Pietro
- Departamento de Genética, Campus de Excelencia Internacional Agroalimentario ceiA3, Universidad de Córdoba, 14071 Córdoba, Spain.
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24
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Miguel-Rojas C, Hera C. The F-box protein Fbp1 functions in the invasive growth and cell wall integrity mitogen-activated protein kinase (MAPK) pathways in Fusarium oxysporum. MOLECULAR PLANT PATHOLOGY 2016; 17:55-64. [PMID: 25808603 PMCID: PMC6638410 DOI: 10.1111/mpp.12259] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
F-box proteins determine substrate specificity of the ubiquitin-proteasome system. Previous work has demonstrated that the F-box protein Fbp1, a component of the SCF(Fbp1) E3 ligase complex, is essential for invasive growth and virulence of the fungal plant pathogen Fusarium oxysporum. Here, we show that, in addition to invasive growth, Fbp1 also contributes to vegetative hyphal fusion and fungal adhesion to tomato roots. All of these functions have been shown previously to require the mitogen-activated protein kinase (MAPK) Fmk1. We found that Fbp1 is required for full phosphorylation of Fmk1, indicating that Fbp1 regulates virulence and invasive growth via the Fmk1 pathway. Moreover, the Δfbp1 mutant is hypersensitive to sodium dodecylsulfate (SDS) and calcofluor white (CFW) and shows reduced phosphorylation levels of the cell wall integrity MAPK Mpk1 after SDS treatment. Collectively, these results suggest that Fbp1 contributes to both the invasive growth and cell wall integrity MAPK pathways of F. oxysporum.
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Affiliation(s)
- Cristina Miguel-Rojas
- Departamento de Genética, Facultad de Ciencias, Universidad de Córdoba, 14071, Córdoba, Spain
- Campus de Excelencia Internacional Agroalimentario ceiA3, 14071, Córdoba, Spain
| | - Concepcion Hera
- Departamento de Genética, Facultad de Ciencias, Universidad de Córdoba, 14071, Córdoba, Spain
- Campus de Excelencia Internacional Agroalimentario ceiA3, 14071, Córdoba, Spain
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Kück U, Beier AM, Teichert I. The composition and function of the striatin-interacting phosphatases and kinases (STRIPAK) complex in fungi. Fungal Genet Biol 2015; 90:31-38. [PMID: 26439752 DOI: 10.1016/j.fgb.2015.10.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 09/30/2015] [Accepted: 10/02/2015] [Indexed: 02/06/2023]
Abstract
The striatin-interacting phosphatases and kinases (STRIPAK) complex is a highly conserved eukaryotic protein complex that was recently described for diverse animal and fungal species. Here, we summarize our current knowledge about the composition and function of the STRIPAK complex from the ascomycete Sordaria macrospora, which we discovered by investigating sexually sterile mutants (pro), having a defect in fruiting body development. Mass spectrometry and yeast two-hybrid analysis defined core subunits of the STRIPAK complex, which have structural homologs in animal and other fungal organisms. These subunits (and their mammalian homologs) are PRO11 (striatin), PRO22 (STRIP1/2), SmMOB3 (Mob3), PRO45 (SLMAP), and PP2AA, the structural, and PP2Ac, the catalytic subunits of protein phosphatase 2A (PP2A). Beside fruiting body formation, the STRIPAK complex controls vegetative growth and hyphal fusion in S. macrospora. Although the contribution of single subunits to diverse cellular and developmental processes is not yet fully understood, functional analysis has already shown that mammalian homologs are able to substitute the function of distinct fungal STRIPAK subunits. This underscores the view that fungal model organisms serve as useful tools to get a molecular insight into cellular and developmental processes of eukaryotes in general. Future work will unravel the precise localization of single subunits within the cell and decipher their STRIPAK-related and STRIPAK-independent functions. Finally, evidence is accumulating that there is a crosstalk between STRIPAK and various signaling pathways, suggesting that eukaryotic development is dependent on STRIPAK signaling.
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Affiliation(s)
- Ulrich Kück
- Lehrstuhl für Allgemeine und Molekulare Botanik, Ruhr-University Bochum, Universitätsstr. 150, 44780 Bochum, Germany.
| | - Anna M Beier
- Lehrstuhl für Allgemeine und Molekulare Botanik, Ruhr-University Bochum, Universitätsstr. 150, 44780 Bochum, Germany
| | - Ines Teichert
- Lehrstuhl für Allgemeine und Molekulare Botanik, Ruhr-University Bochum, Universitätsstr. 150, 44780 Bochum, Germany
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Guo L, Wenner N, Kuldau GA. FvSO regulates vegetative hyphal fusion, asexual growth, fumonisin B1 production, and virulence in Fusarium verticillioides. Fungal Biol 2015; 119:1158-1169. [PMID: 26615739 DOI: 10.1016/j.funbio.2015.08.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 07/24/2015] [Accepted: 08/20/2015] [Indexed: 12/26/2022]
Abstract
Hyphal anastomosis is a hallmark of filamentous fungi and plays vital roles including cellular homoeostasis, interhyphal communication and nutrient translocation. Here we identify a gene, FvSO, in Fusarium verticillioides, a filamentous ascomycete causing maize ear and stalk rot and producing fumonisin mycotoxins. FvSO, like its Neurospora crassa homologue SO, is required for vegetative hyphal fusion. It is also essential for normal vegetative growth, sporulation, and pathogenesis. FvSO encodes a predicted WW domain protein and shares 70 % protein sequence identity with N. crassa SO. FvSO deletion mutants (ΔFvSO) had abnormal distribution of conidia size, and conidia of ΔFvSO germinated much later and slower than wild type. ΔFvSO was deficient in hyphal anastomosis, had slower radial growth and produced less fungal biomass than wild type. ΔFvSO were unable to perform anastomosis, a key feature of filamentous fungi. Interestingly, production of fumonisin B1 by ΔFvSO was significantly reduced compared to wild type. Additionally, ΔFvSO was nonpathogenic to corn ears, stalks and seedlings, likely due to defective growth and development. In conclusion, FvSO is essential for vegetative hyphal fusion and is required for normal vegetative growth and sporulation, normal levels of fumonisin production and pathogenicity in F. verticillioides. The pleiotropic nature of ΔFvSO phenotypes suggests that FvSO is likely involved in certain signalling pathways that regulate multiple cellular functions.
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Affiliation(s)
- Li Guo
- Department of Plant Pathology and Environmental Microbiology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Nancy Wenner
- Department of Plant Pathology and Environmental Microbiology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Gretchen A Kuldau
- Department of Plant Pathology and Environmental Microbiology, The Pennsylvania State University, University Park, PA 16802, USA.
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Frey S, Lahmann Y, Hartmann T, Seiler S, Pöggeler S. Deletion of Smgpi1 encoding a GPI-anchored protein suppresses sterility of the STRIPAK mutant ΔSmmob3 in the filamentous ascomycete Sordaria macrospora. Mol Microbiol 2015; 97:676-97. [PMID: 25989468 DOI: 10.1111/mmi.13054] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/05/2015] [Indexed: 01/06/2023]
Abstract
The striatin interacting phosphatase and kinase (STRIPAK) complex, which is composed of striatin, protein phosphatase PP2A and kinases, is required for fruiting-body development and cell fusion in the filamentous ascomycete Sordaria macrospora. Here, we report on the interplay of the glycosylphosphatidylinositol (GPI)-anchored protein SmGPI1 with the kinase activator SmMOB3, a core component of human and fungal STRIPAK complexes. SmGPI1 is conserved among filamentous ascomycetes and was first identified in a yeast two-hybrid screen using SmMOB3 as bait. The physical interaction of SmMOB3 and SmGPI1 was verified by co-immunoprecipitation. In vivo localization and differential centrifugation revealed that SmGPI1 is predominantly secreted and attached to the cell wall but is also associated with mitochondria and appears to be a dual-targeted protein. Deletion of Smgpi1 led to an increased number of fruiting bodies that were normally shaped but reduced in size. In addition, Smmob3 and Smgpi1 genetically interact. In the sterile ΔSmmob3 background deletion of Smgpi1 restores fertility, vegetative growth as well as hyphal-fusion defects. The suppression effect was specific for the ΔSmmob3 mutant as deletion of Smgpi1 in other STRIPAK mutants does not restore fertility.
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Affiliation(s)
- Stefan Frey
- Institute of Microbiology and Genetics, Department of Genetics of Eukaryotic Microorganisms, Georg-August-University, Göttingen, Germany
| | - Yasmine Lahmann
- Institute of Microbiology and Genetics, Department of Genetics of Eukaryotic Microorganisms, Georg-August-University, Göttingen, Germany
| | - Thomas Hartmann
- Institute of Microbiology and Genetics, Department of Molecular Microbiology and Genetics, Georg-August-University, Göttingen, Germany
| | - Stephan Seiler
- Institute of Microbiology and Genetics, Department of Molecular Microbiology and Genetics, Georg-August-University, Göttingen, Germany.,Göttingen Center for Molecular Biosciences (GZMB), Georg-August-University, Göttingen, Germany
| | - Stefanie Pöggeler
- Institute of Microbiology and Genetics, Department of Genetics of Eukaryotic Microorganisms, Georg-August-University, Göttingen, Germany.,Göttingen Center for Molecular Biosciences (GZMB), Georg-August-University, Göttingen, Germany
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Dettmann A, Heilig Y, Valerius O, Ludwig S, Seiler S. Fungal communication requires the MAK-2 pathway elements STE-20 and RAS-2, the NRC-1 adapter STE-50 and the MAP kinase scaffold HAM-5. PLoS Genet 2014; 10:e1004762. [PMID: 25411845 PMCID: PMC4239118 DOI: 10.1371/journal.pgen.1004762] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 09/18/2014] [Indexed: 11/30/2022] Open
Abstract
Intercellular communication is critical for the survival of unicellular organisms as well as for the development and function of multicellular tissues. Cell-to-cell signaling is also required to develop the interconnected mycelial network characteristic of filamentous fungi and is a prerequisite for symbiotic and pathogenic host colonization achieved by molds. Somatic cell–cell communication and subsequent cell fusion is governed by the MAK-2 mitogen activated protein kinase (MAPK) cascade in the filamentous ascomycete model Neurospora crassa, yet the composition and mode of regulation of the MAK-2 pathway are currently unclear. In order to identify additional components involved in MAK-2 signaling we performed affinity purification experiments coupled to mass spectrometry with strains expressing functional GFP-fusion proteins of the MAPK cascade. This approach identified STE-50 as a regulatory subunit of the Ste11p homolog NRC-1 and HAM-5 as cell-communication-specific scaffold protein of the MAPK cascade. Moreover, we defined a network of proteins consisting of two Ste20-related kinases, the small GTPase RAS-2 and the adenylate cyclase capping protein CAP-1 that function upstream of the MAK-2 pathway and whose signals converge on the NRC-1/STE-50 MAP3K complex and the HAM-5 scaffold. Finally, our data suggest an involvement of the striatin interacting phosphatase and kinase (STRIPAK) complex, the casein kinase 2 heterodimer, the phospholipid flippase modulators YPK-1 and NRC-2 and motor protein-dependent vesicle trafficking in the regulation of MAK-2 pathway activity and function. Taken together, these data will have significant implications for our mechanistic understanding of MAPK signaling and for homotypic cell–cell communication in fungi and higher eukaryotes. Appropriate cellular responses to external stimuli depend on the highly orchestrated activity of interconnected signaling cascades. One crucial level of control arises from the formation of discrete complexes through scaffold proteins that bind multiple components of a given pathway. Central for our understanding of these signaling platforms is the archetypical MAP kinase scaffold Ste5p, a protein that is restricted to budding yeast and close relatives. We identified HAM-5, a protein highly conserved in filamentous ascomycete fungi, as cell–cell communication-specific scaffold protein of the Neurospora crassa MAK-2 cascade (homologous to the budding yeast pheromone pathway). We also describe a network of upstream acting proteins, consisting of two Ste20-related kinases, the small G-protein RAS-2 and the adenylate cyclase capping protein CAP-1, whose signals converge on HAM-5. Our work has implications for the mechanistic understanding of MAP kinase scaffold proteins and their function during intercellular communication in eukaryotic microbes as well as higher eukaryotes.
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Affiliation(s)
- Anne Dettmann
- Institute for Biology II – Molecular Plant Physiology, Albert-Ludwigs University Freiburg, Freiburg, Germany
| | - Yvonne Heilig
- Institute for Biology II – Molecular Plant Physiology, Albert-Ludwigs University Freiburg, Freiburg, Germany
| | - Oliver Valerius
- Institute for Microbiology and Genetics, University of Goettingen, Goettingen, Germany
| | - Sarah Ludwig
- Institute for Biology II – Molecular Plant Physiology, Albert-Ludwigs University Freiburg, Freiburg, 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:
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Chinnici JL, Fu C, Caccamise LM, Arnold JW, Free SJ. Neurospora crassa female development requires the PACC and other signal transduction pathways, transcription factors, chromatin remodeling, cell-to-cell fusion, and autophagy. PLoS One 2014; 9:e110603. [PMID: 25333968 PMCID: PMC4204872 DOI: 10.1371/journal.pone.0110603] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 09/16/2014] [Indexed: 01/01/2023] Open
Abstract
Using a screening protocol we have identified 68 genes that are required for female development in the filamentous fungus Neurospora crassa. We find that we can divide these genes into five general groups: 1) Genes encoding components of the PACC signal transduction pathway, 2) Other signal transduction pathway genes, including genes from the three N. crassa MAP kinase pathways, 3) Transcriptional factor genes, 4) Autophagy genes, and 5) Other miscellaneous genes. Complementation and RIP studies verified that these genes are needed for the formation of the female mating structure, the protoperithecium, and for the maturation of a fertilized protoperithecium into a perithecium. Perithecia grafting experiments demonstrate that the autophagy genes and the cell-to-cell fusion genes (the MAK-1 and MAK-2 pathway genes) are needed for the mobilization and movement of nutrients from an established vegetative hyphal network into the developing protoperithecium. Deletion mutants for the PACC pathway genes palA, palB, palC, palF, palH, and pacC were found to be defective in two aspects of female development. First, they were unable to initiate female development on synthetic crossing medium. However, they could form protoperithecia when grown on cellophane, on corn meal agar, or in response to the presence of nearby perithecia. Second, fertilized perithecia from PACC pathway mutants were unable to produce asci and complete female development. Protein localization experiments with a GFP-tagged PALA construct showed that PALA was localized in a peripheral punctate pattern, consistent with a signaling center associated with the ESCRT complex. The N. crassa PACC signal transduction pathway appears to be similar to the PacC/Rim101 pathway previously characterized in Aspergillus nidulans and Saccharomyces cerevisiae. In N. crassa the pathway plays a key role in regulating female development.
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Affiliation(s)
- Jennifer L. Chinnici
- Department of Biological Sciences, SUNY University at Buffalo, Buffalo, New York, United States of America
| | - Ci Fu
- Department of Biological Sciences, SUNY University at Buffalo, Buffalo, New York, United States of America
| | - Lauren M. Caccamise
- Department of Biological Sciences, SUNY University at Buffalo, Buffalo, New York, United States of America
| | - Jason W. Arnold
- Department of Biological Sciences, SUNY University at Buffalo, Buffalo, New York, United States of America
| | - Stephen J. Free
- Department of Biological Sciences, SUNY University at Buffalo, Buffalo, New York, United States of America
- * E-mail:
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Czárán T, Hoekstra RF, Aanen DK. Selection against somatic parasitism can maintain allorecognition in fungi. Fungal Genet Biol 2014; 73:128-37. [PMID: 25305337 DOI: 10.1016/j.fgb.2014.09.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Revised: 09/25/2014] [Accepted: 09/29/2014] [Indexed: 01/12/2023]
Abstract
Fusion between multicellular individuals is possible in many organisms with modular, indeterminate growth, such as marine invertebrates and fungi. Although fusion may provide various benefits, fusion usually is restricted to close relatives by allorecognition, also called heterokaryon or somatic incompatibility in fungi. A possible selective explanation for allorecognition is protection against somatic parasites. Such mutants contribute less to colony functions but more to reproduction. However, previous models testing this idea have failed to explain the high diversity of allorecognition alleles in nature. These models did not, however, consider the possible role of spatial structure. We model the joint evolution of allorecognition and somatic parasitism in a multicellular organism resembling an asexual ascomycete fungus in a spatially explicit simulation. In a 1000-by-1000 grid, neighbouring individuals can fuse, but only if they have the same allotype. Fusion with a parasitic individual decreases the total reproductive output of the fused individuals, but the parasite compensates for this individual-level fitness reduction by a disproportional share of the offspring. Allorecognition prevents the invasion of somatic parasites, and vice versa, mutation towards somatic parasitism provides the selective conditions for extensive allorecognition diversity. On the one hand, if allorecognition diversity did not build up fast enough, somatic parasites went to fixation; conversely, once parasites had gone to fixation no allorecognition diversity built up. On the other hand, the mere threat of parasitism could select for high allorecognition diversity, preventing invasion of somatic parasites. Moderate population viscosity combined with weak global dispersal was optimal for the joint evolution of allorecognition and protection against parasitism. Our results are consistent with the widespread occurrence of allorecognition in fungi and the low degree of somatic parasitism. We discuss the implications of our results for allorecognition in other organism groups.
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Affiliation(s)
- Tamas Czárán
- MTA-ELTE Research Group of Theoretical Biology and Evolutionary Ecology, Pázmány Péter sétány 1/C, 1117 Budapest, Hungary.
| | - Rolf F Hoekstra
- Laboratory of Genetics, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands.
| | - Duur K Aanen
- Laboratory of Genetics, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands.
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Fu C, Ao J, Dettmann A, Seiler S, Free SJ. Characterization of the Neurospora crassa cell fusion proteins, HAM-6, HAM-7, HAM-8, HAM-9, HAM-10, AMPH-1 and WHI-2. PLoS One 2014; 9:e107773. [PMID: 25279949 PMCID: PMC4184795 DOI: 10.1371/journal.pone.0107773] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 08/14/2014] [Indexed: 11/19/2022] Open
Abstract
Intercellular communication of vegetative cells and their subsequent cell fusion is vital for different aspects of growth, fitness, and differentiation of filamentous fungi. Cell fusion between germinating spores is important for early colony establishment, while hyphal fusion in the mature colony facilitates the movement of resources and organelles throughout an established colony. Approximately 50 proteins have been shown to be important for somatic cell-cell communication and fusion in the model filamentous fungus Neurospora crassa. Genetic, biochemical, and microscopic techniques were used to characterize the functions of seven previously poorly characterized cell fusion proteins. HAM-6, HAM-7 and HAM-8 share functional characteristics and are proposed to function in the same signaling network. Our data suggest that these proteins may form a sensor complex at the cell wall/plasma membrane for the MAK-1 cell wall integrity mitogen-activated protein kinase (MAPK) pathway. We also demonstrate that HAM-9, HAM-10, AMPH-1 and WHI-2 have more general functions and are required for normal growth and development. The activation status of the MAK-1 and MAK-2 MAPK pathways are altered in mutants lacking these proteins. We propose that these proteins may function to coordinate the activities of the two MAPK modules with other signaling pathways during cell fusion.
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Affiliation(s)
- Ci Fu
- Department of Biological Sciences, SUNY University at Buffalo, Buffalo, New York, United States of America
| | - Jie Ao
- Department of Biological Sciences, SUNY University at Buffalo, Buffalo, New York, United States of America
| | - Anne Dettmann
- Institute for Biology II, Albert-Ludwigs University Freiburg, Freiburg, Germany
| | - Stephan Seiler
- Institute for Biology II, Albert-Ludwigs University Freiburg, Freiburg, Germany
- Freiburg Institute for Advanced Studies (FRIAS), Albert-Ludwigs University Freiburg, Freiburg, Germany
| | - Stephen J. Free
- Department of Biological Sciences, SUNY University at Buffalo, Buffalo, New York, United States of America
- * E-mail:
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Teichert I, Steffens EK, Schnaß N, Fränzel B, Krisp C, Wolters DA, Kück U. PRO40 is a scaffold protein of the cell wall integrity pathway, linking the MAP kinase module to the upstream activator protein kinase C. PLoS Genet 2014; 10:e1004582. [PMID: 25188365 PMCID: PMC4154660 DOI: 10.1371/journal.pgen.1004582] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Accepted: 07/02/2014] [Indexed: 12/21/2022] Open
Abstract
Mitogen-activated protein kinase (MAPK) pathways are crucial signaling instruments in eukaryotes. Most ascomycetes possess three MAPK modules that are involved in key developmental processes like sexual propagation or pathogenesis. However, the regulation of these modules by adapters or scaffolds is largely unknown. Here, we studied the function of the cell wall integrity (CWI) MAPK module in the model fungus Sordaria macrospora. Using a forward genetic approach, we found that sterile mutant pro30 has a mutated mik1 gene that encodes the MAPK kinase kinase (MAPKKK) of the proposed CWI pathway. We generated single deletion mutants lacking MAPKKK MIK1, MAPK kinase (MAPKK) MEK1, or MAPK MAK1 and found them all to be sterile, cell fusion-deficient and highly impaired in vegetative growth and cell wall stress response. By searching for MEK1 interaction partners via tandem affinity purification and mass spectrometry, we identified previously characterized developmental protein PRO40 as a MEK1 interaction partner. Although fungal PRO40 homologs have been implicated in diverse developmental processes, their molecular function is currently unknown. Extensive affinity purification, mass spectrometry, and yeast two-hybrid experiments showed that PRO40 is able to bind MIK1, MEK1, and the upstream activator protein kinase C (PKC1). We further found that the PRO40 N-terminal disordered region and the central region encompassing a WW interaction domain are sufficient to govern interaction with MEK1. Most importantly, time- and stress-dependent phosphorylation studies showed that PRO40 is required for MAK1 activity. The sum of our results implies that PRO40 is a scaffold protein for the CWI pathway, linking the MAPK module to the upstream activator PKC1. Our data provide important insights into the mechanistic role of a protein that has been implicated in sexual and asexual development, cell fusion, symbiosis, and pathogenicity in different fungal systems. The specific response to environmental cues is crucial for cell differentiation and is often mediated by highly conserved eukaryotic MAP kinase (MAPK) pathways. How these pathways react specifically to huge numbers of different cues is still unclear, and current literature about adapter and scaffolding proteins remains scarce. However, gaining fundamental insight into molecular signaling determinants is pivotal for combating diseases with impaired signal transduction processes, such as Alzheimer's disease or cancer. Importantly, signal transduction can easily be studied in lower eukaryotes like filamentous fungi that are readily genetically tractable. The fungus Sordaria macrospora has a long history as an ideal model system for cell differentiation, and we show here that the proposed cell wall integrity (CWI) MAPK module of this fungus controls differentiation of sexual fruiting bodies, cell fusion, polar growth and cell wall stress response. We further discovered that developmental protein PRO40 binds the MAPK kinase kinase (MAPKKK), the MAPK kinase (MAPKK) and upstream activator protein kinase C (PKC1) of the CWI pathway and is required for MAK1 activity, thereby providing evidence that PRO40 is a scaffold protein. Collectively, our findings reveal a molecular role for a protein implicated in development, cell fusion, symbiosis, and pathogenicity in different fungi.
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Affiliation(s)
- Ines Teichert
- Department for General and Molecular Botany, Ruhr-University Bochum, Bochum, Germany
| | | | - Nicole Schnaß
- Department for General and Molecular Botany, Ruhr-University Bochum, Bochum, Germany
| | - Benjamin Fränzel
- Department of Analytical Chemistry, Ruhr-University Bochum, Bochum, Germany
| | - Christoph Krisp
- Department of Analytical Chemistry, Ruhr-University Bochum, Bochum, Germany
| | - Dirk A. Wolters
- Department of Analytical Chemistry, Ruhr-University Bochum, Bochum, Germany
| | - Ulrich Kück
- Department for General and Molecular Botany, Ruhr-University Bochum, Bochum, Germany
- * E-mail:
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Bastiaans E, Aanen DK, Debets AJM, Hoekstra RF, Lestrade B, Maas MFPM. Regular bottlenecks and restrictions to somatic fusion prevent the accumulation of mitochondrial defects in Neurospora. Philos Trans R Soc Lond B Biol Sci 2014; 369:20130448. [PMID: 24864316 PMCID: PMC4032522 DOI: 10.1098/rstb.2013.0448] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The replication and segregation of multi-copy mitochondrial DNA (mtDNA) are not under strict control of the nuclear DNA. Within-cell selection may thus favour variants with an intracellular selective advantage but a detrimental effect on cell fitness. High relatedness among the mtDNA variants of an individual is predicted to disfavour such deleterious selfish genetic elements, but experimental evidence for this hypothesis is scarce. We studied the effect of mtDNA relatedness on the opportunities for suppressive mtDNA variants in the fungus Neurospora carrying the mitochondrial mutator plasmid pKALILO. During growth, this plasmid integrates into the mitochondrial genome, generating suppressive mtDNA variants. These mtDNA variants gradually replace the wild-type mtDNA, ultimately culminating in growth arrest and death. We show that regular sequestration of mtDNA variation is required for effective selection against suppressive mtDNA variants. First, bottlenecks in the number of mtDNA copies from which a 'Kalilo' culture started significantly increased the maximum lifespan and variation in lifespan among cultures. Second, restrictions to somatic fusion among fungal individuals, either by using anastomosis-deficient mutants or by generating allotype diversity, prevented the accumulation of suppressive mtDNA variants. We discuss the implications of these results for the somatic accumulation of mitochondrial defects during ageing.
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Affiliation(s)
- E Bastiaans
- Laboratory of Genetics, Wageningen University, Droevendaalsesteeg 1, Wageningen 6708 PB, The Netherlands
| | - D K Aanen
- Laboratory of Genetics, Wageningen University, Droevendaalsesteeg 1, Wageningen 6708 PB, The Netherlands
| | - A J M Debets
- Laboratory of Genetics, Wageningen University, Droevendaalsesteeg 1, Wageningen 6708 PB, The Netherlands
| | - R F Hoekstra
- Laboratory of Genetics, Wageningen University, Droevendaalsesteeg 1, Wageningen 6708 PB, The Netherlands
| | - B Lestrade
- Laboratory of Genetics, Wageningen University, Droevendaalsesteeg 1, Wageningen 6708 PB, The Netherlands
| | - M F P M Maas
- Laboratory of Genetics, Wageningen University, Droevendaalsesteeg 1, Wageningen 6708 PB, The Netherlands
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Hwang J, Pallas DC. STRIPAK complexes: structure, biological function, and involvement in human diseases. Int J Biochem Cell Biol 2014; 47:118-48. [PMID: 24333164 PMCID: PMC3927685 DOI: 10.1016/j.biocel.2013.11.021] [Citation(s) in RCA: 170] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2013] [Revised: 11/18/2013] [Accepted: 11/28/2013] [Indexed: 12/31/2022]
Abstract
The mammalian striatin family consists of three proteins, striatin, S/G2 nuclear autoantigen, and zinedin. Striatin family members have no intrinsic catalytic activity, but rather function as scaffolding proteins. Remarkably, they organize multiple diverse, large signaling complexes that participate in a variety of cellular processes. Moreover, they appear to be regulatory/targeting subunits for the major eukaryotic serine/threonine protein phosphatase 2A. In addition, striatin family members associate with germinal center kinase III kinases as well as other novel components, earning these assemblies the name striatin-interacting phosphatase and kinase (STRIPAK) complexes. Recently, there has been a great increase in functional and mechanistic studies aimed at identifying and understanding the roles of STRIPAK and STRIPAK-like complexes in cellular processes of multiple organisms. These studies have identified novel STRIPAK and STRIPAK-like complexes and have explored their roles in specific signaling pathways. Together, the results of these studies have sparked increased interest in striatin family complexes because they have revealed roles in signaling, cell cycle control, apoptosis, vesicular trafficking, Golgi assembly, cell polarity, cell migration, neural and vascular development, and cardiac function. Moreover, STRIPAK complexes have been connected to clinical conditions, including cardiac disease, diabetes, autism, and cerebral cavernous malformation. In this review, we discuss the expression, localization, and protein domain structure of striatin family members. Then we consider the diverse complexes these proteins and their homologs form in various organisms, emphasizing what is known regarding function and regulation. Finally, we explore possible roles of striatin family complexes in disease, especially cerebral cavernous malformation.
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Affiliation(s)
- Juyeon Hwang
- Department of Biochemistry and Winship Cancer Institute, and Biochemistry, Cell, Developmental Biology Graduate Program, Emory University School of Medicine, 1510 Clifton Road, Atlanta, GA 30322, USA.
| | - David C Pallas
- Department of Biochemistry and Winship Cancer Institute, and Biochemistry, Cell, Developmental Biology Graduate Program, Emory University School of Medicine, 1510 Clifton Road, Atlanta, GA 30322, USA.
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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.
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Affiliation(s)
- Anne Dettmann
- Institute for Biology II - Molecular Plant Physiology, Albert-Ludwigs University Freiburg, Schänzlestr. 1, 79104, Freiburg, Germany
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Abstract
Vegetative fusion is essential for the development of an interconnected colony in many filamentous fungi. In the ascomycete fungus Neurospora crassa, vegetative fusion occurs between germinated conidia (germlings) via specialized structures termed "conidial anastomosis tubes" (CATs) and between hyphae within a mature colony. In N. crassa, both CAT and hyphal fusion are under the regulation of a conserved MAP kinase cascade (NRC1, MEK2, and MAK2). Here we show that the predicted downstream target of the MAK2 kinase pathway, a Ste12-like transcription factor known as PP1, regulates elements required for CAT and hyphal fusion. The PP1 regulatory network was revealed by expression profiling of wild type and the Δpp-1 mutant during conidial germination and colony establishment. To identify targets required for cell fusion more specifically, expression-profiling differences were assessed via inhibition of MAK2 kinase activity during chemotropic interactions and cell fusion. These approaches led to the identification of new targets of the cell fusion pathway that, when mutated, showed alterations in chemotropic signaling and cell fusion. In particular, conidial germlings carrying a deletion of NCU04732 (Δham-11) failed to show chemotropic interactions and cell fusion. However, signaling (as shown by oscillation of MAK2 and SO to CAT tips), chemotropism, and cell fusion were restored in Δham-11 germlings when matched with wild-type partner germlings. These data reveal novel insights into the complex process of self-signaling, germling fusion, and colony establishment in filamentous fungi.
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Pracheil T, Liu Z. Tiered assembly of the yeast Far3-7-8-9-10-11 complex at the endoplasmic reticulum. J Biol Chem 2013; 288:16986-16997. [PMID: 23625923 DOI: 10.1074/jbc.m113.451674] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Target of rapamycin signaling is a conserved, essential pathway integrating nutritional cues with cell growth and proliferation. The target of rapamycin kinase exists in two distinct complexes, TORC1 and TORC2. It has been reported that protein phosphatase 2A (PP2A) and the Far3-7-8-9-10-11 complex (Far complex) negatively regulate TORC2 signaling in yeast. The Far complex, originally identified as factors required for pheromone-induced cell cycle arrest, and PP2A form the yeast counterpart of the STRIPAK complex, which was first isolated in mammals. The cellular localization of the Far complex has yet to be fully characterized. Here, we show that the Far complex localizes to the endoplasmic reticulum (ER) by analyzing functional GFP-tagged Far proteins in vivo. We found that Far9 and Far10, two homologous proteins each with a tail-anchor domain, localize to the ER in mutant cells lacking the other Far complex components. Far3, Far7, and Far8 form a subcomplex, which is recruited to the ER by Far9/10. The Far3-7-8- complex in turn recruits Far11 to the ER. Finally, we show that the tail-anchor domain of Far9 is required for its optimal function in TORC2 signaling. Our study reveals tiered assembly of the yeast Far complex at the ER and a function for Far complex's ER localization in TORC2 signaling.
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Affiliation(s)
- Tammy Pracheil
- Department of Biological Sciences, University of New Orleans, New Orleans, Louisiana 70148
| | - Zhengchang Liu
- Department of Biological Sciences, University of New Orleans, New Orleans, Louisiana 70148.
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Simonin A, Palma-Guerrero J, Fricker M, Glass NL. Physiological significance of network organization in fungi. EUKARYOTIC CELL 2012; 11:1345-52. [PMID: 22962278 PMCID: PMC3486018 DOI: 10.1128/ec.00213-12] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Accepted: 09/01/2012] [Indexed: 01/16/2023]
Abstract
The evolution of multicellularity has occurred in diverse lineages and in multiple ways among eukaryotic species. For plants and fungi, multicellular forms are derived from ancestors that failed to separate following cell division, thus retaining cytoplasmic continuity between the daughter cells. In networked organisms, such as filamentous fungi, cytoplasmic continuity facilitates the long-distance transport of resources without the elaboration of a separate vascular system. Nutrient translocation in fungi is essential for nutrient cycling in ecosystems, mycorrhizal symbioses, virulence, and substrate utilization. It has been proposed that an interconnected mycelial network influences resource translocation, but the theory has not been empirically tested. Here we show, by using mutants that disrupt network formation in Neurospora crassa (Δso mutant, no fusion; ΔPrm-1 mutant, ∼50% fusion), that the translocation of labeled nutrients is adversely affected in homogeneous environments and is even more severely impacted in heterogeneous environments. We also show that the ability to share resources and genetic exchange between colonies (via hyphal fusion) is very limited in mature colonies, in contrast to in young colonies and germlings that readily share nutrients and genetic resources. The differences in genetic/resource sharing between young and mature colonies were associated with variations in colony architecture (hyphal differentiation/diameters, branching patterns, and angles). Thus, the ability to share resources and genetic material between colonies is developmentally regulated and is a function of the age of a colony. This study highlights the necessity of hyphal fusion for efficient nutrient translocation within an N. crassa colony but also shows that established N. crassa colonies do not share resources in a significant manner.
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Affiliation(s)
- Anna Simonin
- Plant and Microbial Biology Department, The University of California, Berkeley, California, USA
| | - Javier Palma-Guerrero
- Plant and Microbial Biology Department, The University of California, Berkeley, California, USA
| | - Mark Fricker
- Department of Plant Sciences, University of Oxford, Oxford, United Kingdom
| | - N. Louise Glass
- Plant and Microbial Biology Department, The University of California, Berkeley, California, USA
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Deletion of the fungal gene soft disrupts mutualistic symbiosis between the grass endophyte Epichloë festucae and the host plant. EUKARYOTIC CELL 2012; 11:1463-71. [PMID: 23042130 DOI: 10.1128/ec.00191-12] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Hyphal anastomosis, or vegetative hyphal fusion, establishes the interconnection of individual hyphal strands into an integrated network of a fungal mycelium. In contrast to recent advances in the understanding of the molecular basis for hyphal anastomosis, knowledge of the physiological role of hyphal anastomosis in the natural habitats of filamentous fungi is still very limited. To investigate the role of hyphal anastomosis in fungal endophyte-plant interactions, we generated mutant strains lacking the Epichloë festucae soft (so) gene, an ortholog of the hyphal anastomosis gene so in the endophytic fungus E. festucae. The E. festucae Δso mutant strains grew similarly to the wild-type strain in culture but with reduced aerial hyphae and completely lacked hyphal anastomosis. The most striking phenotype of the E. festucae Δso mutant strain was that it failed to establish a mutualistic symbiosis with the tall fescue plant host (Lolium arundinaceum); instead, it killed the host plant within 2 months after the initial infection. Microscopic examination revealed that the death of the tall fescue plant host was associated with the distortion and disorganization of plant cells. This study suggests that hyphal anastomosis may have an important role in the establishment/maintenance of fungal endophyte-host plant mutualistic symbiosis.
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Lichius A, Lord KM, Jeffree CE, Oborny R, Boonyarungsrit P, Read ND. Importance of MAP kinases during protoperithecial morphogenesis in Neurospora crassa. PLoS One 2012; 7:e42565. [PMID: 22900028 PMCID: PMC3416862 DOI: 10.1371/journal.pone.0042565] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2012] [Accepted: 07/09/2012] [Indexed: 02/06/2023] Open
Abstract
In order to produce multicellular structures filamentous fungi combine various morphogenetic programs that are fundamentally different from those used by plants and animals. The perithecium, the female sexual fruitbody of Neurospora crassa, differentiates from the vegetative mycelium in distinct morphological stages, and represents one of the more complex multicellular structures produced by fungi. In this study we defined the stages of protoperithecial morphogenesis in the N. crassa wild type in greater detail than has previously been described; compared protoperithecial morphogenesis in gene-deletion mutants of all nine mitogen-activated protein (MAP) kinases conserved in N. crassa; confirmed that all three MAP kinase cascades are required for sexual development; and showed that the three different cascades each have distinctly different functions during this process. However, only MAP kinases equivalent to the budding yeast pheromone response and cell wall integrity pathways, but not the osmoregulatory pathway, were essential for vegetative cell fusion. Evidence was obtained for MAP kinase signaling cascades performing roles in extracellular matrix deposition, hyphal adhesion, and envelopment during the construction of fertilizable protoperithecia.
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Affiliation(s)
- Alexander Lichius
- Fungal Cell Biology Group, Institute of Cell Biology, The University of Edinburgh, Edinburgh, United Kingdom
| | - Kathryn M. Lord
- Fungal Cell Biology Group, Institute of Cell Biology, The University of Edinburgh, Edinburgh, United Kingdom
| | - Chris E. Jeffree
- Institute of Molecular Plant Sciences, The University of Edinburgh, Edinburgh, United Kingdom
| | - Radek Oborny
- Fungal Cell Biology Group, Institute of Cell Biology, The University of Edinburgh, Edinburgh, United Kingdom
| | - Patid Boonyarungsrit
- Fungal Cell Biology Group, Institute of Cell Biology, The University of Edinburgh, Edinburgh, United Kingdom
| | - Nick D. Read
- Fungal Cell Biology Group, Institute of Cell Biology, The University of Edinburgh, Edinburgh, United Kingdom
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Maddi A, Dettman A, Fu C, Seiler S, Free SJ. WSC-1 and HAM-7 are MAK-1 MAP kinase pathway sensors required for cell wall integrity and hyphal fusion in Neurospora crassa. PLoS One 2012; 7:e42374. [PMID: 22879952 PMCID: PMC3411791 DOI: 10.1371/journal.pone.0042374] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2012] [Accepted: 07/04/2012] [Indexed: 11/18/2022] Open
Abstract
A large number of cell wall proteins are encoded in the Neurospora crassa genome. Strains carrying gene deletions of 65 predicted cell wall proteins were characterized. Deletion mutations in two of these genes (wsc-1 and ham-7) have easily identified morphological and inhibitor-based defects. Their phenotypic characterization indicates that HAM-7 and WSC-1 function during cell-to-cell hyphal fusion and in cell wall integrity maintenance, respectively. wsc-1 encodes a transmembrane protein with extensive homology to the yeast Wsc family of sensor proteins. In N. crassa, WSC-1 (and its homolog WSC-2) activates the cell wall integrity MAK-1 MAP kinase pathway. The GPI-anchored cell wall protein HAM-7 is required for cell-to-cell fusion and the sexual stages of the N. crassa life cycle. Like WSC-1, HAM-7 is required for activating MAK-1. A Δwsc-1;Δham-7 double mutant fully phenocopies mutants lacking components of the MAK-1 MAP kinase cascade. The data identify WSC-1 and HAM-7 as the major cell wall sensors that regulate two distinct MAK-1-dependent cellular activities, cell wall integrity and hyphal anastomosis, respectively.
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Affiliation(s)
- Abhiram Maddi
- Department of Biological Sciences, State University of New York, University at Buffalo, Buffalo, New York, United States of America
- Department of Periodontics and Endodontics, School of Dental Medicine, State University of New York, University at Buffalo, Buffalo, New York, United States of America
| | - Anne Dettman
- Institute for Microbiology and Genetics, Department of Molecular Microbiology and Genetics, Georg-August-University, Göttingen, Germany
| | - Ci Fu
- Department of Biological Sciences, State University of New York, University at Buffalo, Buffalo, New York, United States of America
| | - Stephan Seiler
- Institute for Microbiology and Genetics, Department of Molecular Microbiology and Genetics, Georg-August-University, Göttingen, Germany
- * E-mail: (SS); (SF)
| | - Stephen J. Free
- Department of Biological Sciences, State University of New York, University at Buffalo, Buffalo, New York, United States of America
- * E-mail: (SS); (SF)
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Read ND, Goryachev AB, Lichius A. The mechanistic basis of self-fusion between conidial anastomosis tubes during fungal colony initiation. FUNGAL BIOL REV 2012. [DOI: 10.1016/j.fbr.2012.02.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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45
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Bloemendal S, Bernhards Y, Bartho K, Dettmann A, Voigt O, Teichert I, Seiler S, Wolters DA, Pöggeler S, Kück U. A homologue of the human STRIPAK complex controls sexual development in fungi. Mol Microbiol 2012; 84:310-23. [PMID: 22375702 DOI: 10.1111/j.1365-2958.2012.08024.x] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Sexual development in fungi is a complex process involving the generation of new cell types and tissues - an essential step for all eukaryotic life. The characterization of sterile mutants in the ascomycete Sordaria macrospora has led to a number of proteins involved in sexual development, but a link between these proteins is still missing. Using a combined tandem-affinity purification/mass spectrometry approach, we showed in vivo association of developmental protein PRO22 with PRO11, homologue of mammalian striatin, and SmPP2AA, scaffolding subunit of protein phosphatase 2A. Further experiments extended the protein network to the putative kinase activator SmMOB3, known to be involved in sexual development. Extensive yeast two-hybrid studies allowed us to pinpoint functional domains involved in protein-protein interaction. We show for the first time that a number of already known factors together with new components associate in vivo to form a highly conserved multi-subunit complex. Strikingly, a similar complex has been described in humans, but the function of this so-called striatin interacting phosphatase and kinase (STRIPAK) complex is largely unknown. In S. macrospora, truncation of PRO11 and PRO22 leads to distinct defects in sexual development and cell fusion, indicating a role for the fungal STRIPAK complex in both processes.
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Affiliation(s)
- Sandra Bloemendal
- Lehrstuhl für Allgemeine und Molekulare Botanik, Ruhr-Universität Bochum, Universitätsstr. 150, 44780 Bochum, Germany
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TORC2 signaling is antagonized by protein phosphatase 2A and the Far complex in Saccharomyces cerevisiae. Genetics 2012; 190:1325-39. [PMID: 22298706 DOI: 10.1534/genetics.111.138305] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The target of rapamycin (TOR) kinase, a central regulator of eukaryotic cell growth, exists in two essential, yet distinct, TOR kinase complexes in the budding yeast Saccharomyces cerevisiae: rapamycin-sensitive TORC1 and rapamycin-insensitive TORC2. Lst8, a component of both TOR complexes, is essential for cell viability. However, it is unclear whether the essential function of Lst8 is linked to TORC1, TORC2, or both. To that end, we carried out a genetic screen to isolate lst8 deletion suppressor mutants. Here we report that mutations in SAC7 and FAR11 suppress lethality of lst8Δ and TORC2-deficient (tor2-21) mutations but not TORC1 inactivation, suggesting that the essential function of Lst8 is linked only to TORC2. More importantly, characterization of lst8Δ bypass mutants reveals a role for protein phosphatase 2A (PP2A) in the regulation of TORC2 signaling. We show that Far11, a member of the Far3-7-8-9-10-11 complex involved in pheromone-induced cell cycle arrest, interacts with Tpd3 and Pph21, conserved components of PP2A, and deletions of components of the Far3-7-8-9-10-11 complex and PP2A rescue growth defects in lst8Δ and tor2-21 mutants. In addition, loss of the regulatory B' subunit of PP2A Rts1 or Far11 restores phosphorylation to the TORC2 substrate Slm1 in a tor2-21 mutant. Mammalian Far11 orthologs FAM40A/B exist in a complex with PP2A known as STRIPAK, suggesting a conserved functional association of PP2A and Far11. Antagonism of TORC2 signaling by PP2A-Far11 represents a novel regulatory mechanism for controlling spatial cell growth of yeast.
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Goryachev AB, Lichius A, Wright GD, Read ND. Excitable behavior can explain the "ping-pong" mode of communication between cells using the same chemoattractant. Bioessays 2012; 34:259-66. [PMID: 22271443 DOI: 10.1002/bies.201100135] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Here we elucidate a paradox: how a single chemoattractant-receptor system in two individuals is used for communication despite the seeming inevitability of self-excitation. In the filamentous fungus Neurospora crassa, genetically identical cells that produce the same chemoattractant fuse via the homing of individual cell protrusions toward each other. This is achieved via a recently described "ping-pong" pulsatile communication. Using a generic activator-inhibitor model of excitable behavior, we demonstrate that the pulse exchange can be fully understood in terms of two excitable systems locked into a stable oscillatory pattern of mutual excitation. The most puzzling properties of this communication are the sudden onset of oscillations with final amplitude, and the absence of seemingly inevitable self-excitation. We show that these properties result directly from both the excitability threshold and refractory period characteristic of excitable systems. Our model suggests possible molecular mechanisms for the ping-pong communication.
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Bidard F, Aït Benkhali J, Coppin E, Imbeaud S, Grognet P, Delacroix H, Debuchy R. Genome-wide gene expression profiling of fertilization competent mycelium in opposite mating types in the heterothallic fungus Podospora anserina. PLoS One 2011; 6:e21476. [PMID: 21738678 PMCID: PMC3125171 DOI: 10.1371/journal.pone.0021476] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Accepted: 05/29/2011] [Indexed: 12/15/2022] Open
Abstract
Background Mating-type loci in yeasts and ascomycotan filamentous fungi (Pezizomycotina) encode master transcriptional factors that play a critical role in sexual development. Genome-wide analyses of mating-type-specification circuits and mating-type target genes are available in Saccharomyces cerevisiae and Schizosaccharomyces pombe; however, no such analyses have been performed in heterothallic (self-incompatible) Pezizomycotina. The heterothallic fungus Podospora anserina serves as a model for understanding the basic features of mating-type control. Its mat+ and mat− mating types are determined by dissimilar allelic sequences. The mat− sequence contains three genes, designated FMR1, SMR1 and SMR2, while the mat+ sequence contains one gene, FPR1. FMR1 and FPR1 are the major regulators of fertilization, and this study presents a genome-wide view of their target genes and analyzes their target gene regulation. Methodology/Principal Findings The transcriptomic profiles of the mat+ and mat− strains revealed 157 differentially transcribed genes, and transcriptomic analysis of fmr1− and fpr1− mutant strains was used to determine the regulatory actions exerted by FMR1 and FPR1 on these differentially transcribed genes. All possible combinations of transcription repression and/or activation by FMR1 and/or FPR1 were observed. Furthermore, 10 additional mating-type target genes were identified that were up- or down-regulated to the same level in mat+ and mat− strains. Of the 167 genes identified, 32 genes were selected for deletion, which resulted in the identification of two genes essential for the sexual cycle. Interspecies comparisons of mating-type target genes revealed significant numbers of orthologous pairs, although transcriptional profiles were not conserved between species. Conclusions/Significance This study represents the first comprehensive genome-wide analysis of mating-type direct and indirect target genes in a heterothallic filamentous fungus. Mating-type transcription factors have many more target genes than are found in yeasts and exert a much greater diversity of regulatory actions on target genes, most of which are not directly related to mating.
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Affiliation(s)
- Frédérique Bidard
- Univ Paris-Sud, Institut de Génétique et Microbiologie UMR8621, Orsay, France
- CNRS, Institut de Génétique et Microbiologie UMR8621, Orsay, France
| | - Jinane Aït Benkhali
- Univ Paris-Sud, Institut de Génétique et Microbiologie UMR8621, Orsay, France
- CNRS, Institut de Génétique et Microbiologie UMR8621, Orsay, France
| | - Evelyne Coppin
- Univ Paris-Sud, Institut de Génétique et Microbiologie UMR8621, Orsay, France
- CNRS, Institut de Génétique et Microbiologie UMR8621, Orsay, France
| | - Sandrine Imbeaud
- CNRS, Centre de Génétique Moléculaire FRE3144, GODMAP, Gif sur Yvette, France
| | - Pierre Grognet
- Univ Paris-Sud, Institut de Génétique et Microbiologie UMR8621, Orsay, France
- UFR des Sciences du Vivant, Université Paris 7-Denis Diderot, Paris, France
| | - Hervé Delacroix
- CNRS, Centre de Génétique Moléculaire FRE3144, GODMAP, Gif sur Yvette, France
- Univ Paris-Sud, Orsay, France
| | - Robert Debuchy
- Univ Paris-Sud, Institut de Génétique et Microbiologie UMR8621, Orsay, France
- CNRS, Institut de Génétique et Microbiologie UMR8621, Orsay, France
- * E-mail:
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Identification and characterization of genes required for cell-to-cell fusion in Neurospora crassa. EUKARYOTIC CELL 2011; 10:1100-9. [PMID: 21666072 DOI: 10.1128/ec.05003-11] [Citation(s) in RCA: 125] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A screening procedure was used to identify cell fusion (hyphal anastomosis) mutants in the Neurospora crassa single gene deletion library. Mutants with alterations in 24 cell fusion genes required for cell fusion between conidial anastomosis tubes (CATs) were identified and characterized. The cell fusion genes identified included 14 genes that are likely to function in signal transduction pathways needed for cell fusion to occur (mik-1, mek-1, mak-1, nrc-1, mek-2, mak-2, rac-1, pp2A, so/ham-1, ham-2, ham-3, ham-5, ham-9, and mob3). The screening experiments also identified four transcription factors that are required for cell fusion (adv-1, ada-3, rco-1, and snf5). Three genes encoding proteins likely to be involved in the process of vesicular trafficking were also identified as needed for cell fusion during the screening (amph-1, ham-10, pkr1). Three of the genes identified by the screening procedure, ham-6, ham-7, and ham-8, encode proteins that might function in mediating the plasma membrane fusion event. Three of the putative signal transduction proteins, three of the transcription factors, the three putative vesicular trafficking proteins, and the three proteins that might function in mediating cell fusion had not been identified previously as required for cell fusion.
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50
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Kean MJ, Ceccarelli DF, Goudreault M, Sanches M, Tate S, Larsen B, Gibson LCD, Derry WB, Scott IC, Pelletier L, Baillie GS, Sicheri F, Gingras AC. Structure-function analysis of core STRIPAK Proteins: a signaling complex implicated in Golgi polarization. J Biol Chem 2011; 286:25065-75. [PMID: 21561862 DOI: 10.1074/jbc.m110.214486] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Cerebral cavernous malformations (CCMs) are alterations in brain capillary architecture that can result in neurological deficits, seizures, or stroke. We recently demonstrated that CCM3, a protein mutated in familial CCMs, resides predominantly within the STRIPAK complex (striatin interacting phosphatase and kinase). Along with CCM3, STRIPAK contains the Ser/Thr phosphatase PP2A. The PP2A holoenzyme consists of a core catalytic subunit along with variable scaffolding and regulatory subunits. Within STRIPAK, striatin family members act as PP2A regulatory subunits. STRIPAK also contains all three members of a subfamily of Sterile 20 kinases called the GCKIII proteins (MST4, STK24, and STK25). Here, we report that striatins and CCM3 bridge the phosphatase and kinase components of STRIPAK and map the interacting regions on each protein. We show that striatins and CCM3 regulate the Golgi localization of MST4 in an opposite manner. Consistent with a previously described function for MST4 and CCM3 in Golgi positioning, depletion of CCM3 or striatins affects Golgi polarization, also in an opposite manner. We propose that STRIPAK regulates the balance between MST4 localization at the Golgi and in the cytosol to control Golgi positioning.
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Affiliation(s)
- Michelle J Kean
- Samuel Lunenfeld Research Institute at Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada
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