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Nguyen TP, Meng DR, Chang CH, Su PY, Ou CA, Hou PF, Sung HM, Chou CH, Ohme-Takagi M, Huang HJ. Antifungal mechanism of volatile compounds emitted by Actinomycetota Paenarthrobacter ureafaciens from a disease-suppressive soil on Saccharomyces cerevisiae. mSphere 2023; 8:e0032423. [PMID: 37750721 PMCID: PMC10597458 DOI: 10.1128/msphere.00324-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Accepted: 08/07/2023] [Indexed: 09/27/2023] Open
Abstract
Increasing evidence suggests that in disease-suppressive soils, microbial volatile compounds (mVCs) released from bacteria may inhibit the growth of plant-pathogenic fungi. However, the antifungal activities and molecular responses of fungi to different mVCs remain largely undescribed. In this study, we first evaluated the responses of pathogenic fungi to treatment with mVCs from Paenarthrobacter ureafaciens. Then, we utilized the well-characterized fungal model organism Saccharomyces cerevisiae to study the potential mechanistic effects of the mVCs. Our data showed that exposure to P. ureafaciens mVCs leads to reduced growth of several pathogenic fungi, and in yeast cells, mVC exposure prompts the accumulation of reactive oxygen species. Further experiments with S. cerevisiae deletion mutants indicated that Slt2/Mpk1 and Hog1 MAPKs play major roles in the yeast response to P. ureafaciens mVCs. Transcriptomic analysis revealed that exposure to mVCs was associated with 1,030 differentially expressed genes (DEGs) in yeast. According to gene ontology and Kyoto Encyclopedia of Genes and Genomes analyses, many of these DEGs are involved in mitochondrial dysfunction, cell integrity, mitophagy, cellular metabolism, and iron uptake. Genes encoding antimicrobial proteins were also significantly altered in the yeast after exposure to mVCs. These findings suggest that oxidative damage and mitochondrial dysfunction are major contributors to the fungal toxicity of mVCs. Furthermore, our data showed that cell wall, antioxidant, and antimicrobial defenses are induced in yeast exposed to mVCs. Thus, our findings expand upon previous research by delineating the transcriptional responses of the fungal model. IMPORTANCE Since the use of bacteria-emitted volatile compounds in phytopathogen control is of considerable interest, it is important to understand the molecular mechanisms by which fungi may adapt to microbial volatile compounds (mVCs). Paenarthrobacter ureafaciens is an isolated bacterium from disease-suppressive soil that belongs to the Actinomycetota phylum. P. ureafaciens mVCs showed a potent antifungal effect on phytopathogens, which may contribute to disease suppression in soil. However, our knowledge about the antifungal mechanism of mVCs is limited. This study has proven that mVCs are toxic to fungi due to oxidative stress and mitochondrial dysfunction. To deal with mVC toxicity, antioxidants and physical defenses are required. Furthermore, iron uptake and CAP proteins are required for antimicrobial defense, which is necessary for fungi to deal with the thread from mVCs. This study provides essential foundational knowledge regarding the molecular responses of fungi to inhibitory mVCs.
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Affiliation(s)
- Tri-Phuong Nguyen
- Department of Life Sciences, National Cheng Kung University, Tainan, Taiwan
| | - De-Rui Meng
- Department of Life Sciences, National Cheng Kung University, Tainan, Taiwan
| | - Ching-Han Chang
- Graduate Program in Translational Agricultural Sciences, National Cheng Kung University and Academia Sinica, Tainan, Taiwan
| | - Pei-Yu Su
- Department of Life Sciences, National Cheng Kung University, Tainan, Taiwan
| | - Chieh-An Ou
- Department of Life Sciences, National Cheng Kung University, Tainan, Taiwan
| | - Ping-Fu Hou
- Kaohsiung District Agricultural Research and Extension Station, Pingtung, Taiwan
| | - Huang-Mo Sung
- Department of Life Sciences, National Cheng Kung University, Tainan, Taiwan
| | - Chang-Hung Chou
- Department of Life Sciences, National Cheng Kung University, Tainan, Taiwan
| | - Masaru Ohme-Takagi
- Institute of Tropical Plant Sciences and Microbiology, National Cheng Kung University, Tainan, Taiwan
| | - Hao-Jen Huang
- Department of Life Sciences, National Cheng Kung University, Tainan, Taiwan
- Graduate Program in Translational Agricultural Sciences, National Cheng Kung University and Academia Sinica, Tainan, Taiwan
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Martínez-Matías N, Chorna N, González-Crespo S, Villanueva L, Montes-Rodríguez I, Melendez-Aponte LM, Roche-Lima A, Carrasquillo-Carrión K, Santiago-Cartagena E, Rymond BC, Babu M, Stagljar I, Rodríguez-Medina JR. Toward the discovery of biological functions associated with the mechanosensor Mtl1p of Saccharomyces cerevisiae via integrative multi-OMICs analysis. Sci Rep 2021; 11:7411. [PMID: 33795741 PMCID: PMC8016984 DOI: 10.1038/s41598-021-86671-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 03/15/2021] [Indexed: 02/06/2023] Open
Abstract
Functional analysis of the Mtl1 protein in Saccharomyces cerevisiae has revealed that this transmembrane sensor endows yeast cells with resistance to oxidative stress through a signaling mechanism called the cell wall integrity pathway (CWI). We observed upregulation of multiple heat shock proteins (HSPs), proteins associated with the formation of stress granules, and the phosphatase subunit of trehalose 6-phosphate synthase which suggests that mtl1Δ strains undergo intrinsic activation of a non-lethal heat stress response. Furthermore, quantitative global proteomic analysis conducted on TMT-labeled proteins combined with metabolome analysis revealed that mtl1Δ strains exhibit decreased levels of metabolites of carboxylic acid metabolism, decreased expression of anabolic enzymes and increased expression of catabolic enzymes involved in the metabolism of amino acids, with enhanced expression of mitochondrial respirasome proteins. These observations support the idea that Mtl1 protein controls the suppression of a non-lethal heat stress response under normal conditions while it plays an important role in metabolic regulatory mechanisms linked to TORC1 signaling that are required to maintain cellular homeostasis and optimal mitochondrial function.
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Affiliation(s)
- Nelson Martínez-Matías
- grid.267033.30000 0004 0462 1680Department of Biochemistry, Medical Sciences Campus, University of Puerto Rico, San Juan, PR 00936-5067 USA
| | - Nataliya Chorna
- grid.267033.30000 0004 0462 1680Department of Biochemistry, Medical Sciences Campus, University of Puerto Rico, San Juan, PR 00936-5067 USA
| | - Sahily González-Crespo
- grid.267033.30000 0004 0462 1680Department of Biochemistry, Medical Sciences Campus, University of Puerto Rico, San Juan, PR 00936-5067 USA
| | - Lilliam Villanueva
- grid.267033.30000 0004 0462 1680Department of Biochemistry, Medical Sciences Campus, University of Puerto Rico, San Juan, PR 00936-5067 USA
| | - Ingrid Montes-Rodríguez
- Comprehensive Cancer Center, University of Puerto Rico, Puerto Rico Medical Center, Rio Piedras, PR 00936-3027 USA
| | - Loyda M. Melendez-Aponte
- grid.267033.30000 0004 0462 1680Department of Biochemistry, Medical Sciences Campus, University of Puerto Rico, San Juan, PR 00936-5067 USA
| | - Abiel Roche-Lima
- grid.267033.30000 0004 0462 1680Department of Biochemistry, Medical Sciences Campus, University of Puerto Rico, San Juan, PR 00936-5067 USA
| | - Kelvin Carrasquillo-Carrión
- grid.267033.30000 0004 0462 1680Department of Biochemistry, Medical Sciences Campus, University of Puerto Rico, San Juan, PR 00936-5067 USA
| | - Ednalise Santiago-Cartagena
- grid.267033.30000 0004 0462 1680Department of Biochemistry, Medical Sciences Campus, University of Puerto Rico, San Juan, PR 00936-5067 USA
| | - Brian C. Rymond
- grid.266539.d0000 0004 1936 8438Department of Biology, University of Kentucky, Lexington, KY 40506 USA
| | - Mohan Babu
- grid.57926.3f0000 0004 1936 9131Department of Biochemistry, University of Regina, Regina, SK S4S 0A2 Canada
| | - Igor Stagljar
- grid.17063.330000 0001 2157 2938Donnelly Centre, Department of Biochemistry, Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 3E1 Canada ,grid.482535.d0000 0004 4663 8413Mediterranean Institute for Life Sciences, Split, Croatia
| | - José R. Rodríguez-Medina
- grid.267033.30000 0004 0462 1680Department of Biochemistry, Medical Sciences Campus, University of Puerto Rico, San Juan, PR 00936-5067 USA
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3
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Nomura W, Futamata R, Inoue Y. Role of RhoGAP Rgd1 in Pkc1 signaling-related actin repolarization under heat shock stress in Saccharomyces cerevisiae. Biochim Biophys Acta Gen Subj 2021; 1865:129853. [PMID: 33508381 DOI: 10.1016/j.bbagen.2021.129853] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 01/13/2021] [Accepted: 01/19/2021] [Indexed: 11/16/2022]
Abstract
BACKGROUND A serine/threonine kinase Pkc1 is the sole protein kinase C in the budding yeast Saccharomyces cerevisiae, and plays an important role in the regulation of polarized growth and stress responses such as those due to heat shock. Exposure of cells to high temperature transiently arrests polarized growth and leads to depolarization of the actin cytoskeleton, followed by actin repolarization during adaptation to heat shock stress. Actin repolarization is ensured by the activation of Pkc1 signaling; however, the molecular mechanisms underlying this phenomenon remain poorly understood. METHODS Using an overexpression construct of a constitutively active mutant of Pkc1 (Pkc1R398P), we explored the Pkc1 target molecules involved in actin repolarization. RESULTS PKC1R398P overexpression as well as heat shock stress increased the phosphorylation levels of Rho GTPase-activating protein (RhoGAP) Rgd1. Rgd1 was found to contribute to Pkc1-signaling-related actin repolarization during adaptation to heat shock stress in a GAP activity-independent manner, with Ser148 in Rgd1 playing a crucial role. Furthermore, Rgd1 was involved in the maintenance of phosphorylation status of the mitogen-activated protein (MAP) kinase Mpk1, a downstream effector of Pkc1, under heat shock stress. CONCLUSIONS Rgd1 is a target of Pkc1 signaling under conditions of heat shock stress, and required for the normal process of actin repolarization during adaptation to heat shock stress. GENERAL SIGNIFICANCE Our results provide insights into the molecular mechanism underlying Pkc1-mediated modulation of actin repolarization under heat shock stress.
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Affiliation(s)
- Wataru Nomura
- Laboratory of Molecular Microbiology, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan; Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan.
| | - Ryota Futamata
- Laboratory of Molecular Microbiology, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Yoshiharu Inoue
- Laboratory of Molecular Microbiology, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan.
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Wang S, Li G, Wei Y, Wang G, Dang Y, Zhang P, Zhang SH. Involvement of the Mitochondrial Protein Tyrosine Phosphatase PTPM1 in the Promotion of Conidiation, Development, and Pathogenicity in Colletotrichum graminicola. Front Microbiol 2021; 11:605738. [PMID: 33519752 PMCID: PMC7841309 DOI: 10.3389/fmicb.2020.605738] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Accepted: 12/21/2020] [Indexed: 12/13/2022] Open
Abstract
The phosphorylation status of proteins, which is determined by protein tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPs), governs many cellular actions. In fungal pathogens, phosphorylation-mediated signal transduction has been considered to be one of the most important mechanisms in pathogenicity. Colletotrichum graminicola is an economically important corn pathogen. However, whether phosphorylation is involved in its pathogenicity is unknown. A mitochondrial protein tyrosine phosphatase gene, designated CgPTPM1, was deduced in C. graminicola through the use of bioinformatics and confirmed by enzyme activity assays and observation of its subcellular localization. We then created a CgPTPM1 deletion mutant (ΔCgPTPM1) to analyze its biological function. The results indicated that the loss of CgPTPM1 dramatically affected the formation of conidia and the development and differentiation into appressoria. However, the colony growth and conidial morphology of the ΔCgPTPM1 strains were unaffected. Importantly, the ΔCgPTPM1 mutant strains exhibited an obvious reduction of virulence, and the delayed infected hyphae failed to expand in the host cells. In comparison with the wild-type, ΔCgPTPM1 accumulated a larger amount of H2O2 and was sensitive to exogenous H2O2. Interestingly, the host cells infected by the mutant also exhibited an increased accumulation of H2O2 around the infection sites. Since the expression of the CgHYR1, CgGST1, CgGLR1, CgGSH1 and CgPAP1 genes was upregulated with the H2O2 treatment, our results suggest that the mitochondrial protein tyrosine phosphatase PTPM1 plays an essential role in promoting the pathogenicity of C. graminicola by regulating the excessive in vivo and in vitro production of H2O2.
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Affiliation(s)
- Shaowei Wang
- College of Plant Sciences, Jilin University, Changchun, China
| | - Guihua Li
- College of Plant Sciences, Jilin University, Changchun, China
- Key Laboratory of Zoonosis Research, Ministry of Education, Jilin University, Changchun, China
| | - Yi Wei
- College of Plant Sciences, Jilin University, Changchun, China
- College of Plant Protection, Shenyang Agricultural University, Shenyang, China
| | - Gang Wang
- School of Life Sciences, Henan University, Kaifeng, China
| | - Yuejia Dang
- College of Plant Sciences, Jilin University, Changchun, China
| | - Penghui Zhang
- College of Plant Sciences, Jilin University, Changchun, China
| | - Shi-Hong Zhang
- College of Plant Sciences, Jilin University, Changchun, China
- College of Plant Protection, Shenyang Agricultural University, Shenyang, China
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5
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Martin-Yken H. Yeast-Based Biosensors: Current Applications and New Developments. BIOSENSORS 2020; 10:E51. [PMID: 32413968 PMCID: PMC7277604 DOI: 10.3390/bios10050051] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 04/17/2020] [Accepted: 04/20/2020] [Indexed: 12/23/2022]
Abstract
Biosensors are regarded as a powerful tool to detect and monitor environmental contaminants, toxins, and, more generally, organic or chemical markers of potential threats to human health. They are basically composed of a sensor part made up of either live cells or biological active molecules coupled to a transducer/reporter technological element. Whole-cells biosensors may be based on animal tissues, bacteria, or eukaryotic microorganisms such as yeasts and microalgae. Although very resistant to adverse environmental conditions, yeasts can sense and respond to a wide variety of stimuli. As eukaryotes, they also constitute excellent cellular models to detect chemicals and organic contaminants that are harmful to animals. For these reasons, combined with their ease of culture and genetic modification, yeasts have been commonly used as biological elements of biosensors since the 1970s. This review aims first at giving a survey on the different types of yeast-based biosensors developed for the environmental and medical domains. We then present the technological developments currently undertaken by academic and corporate scientists to further drive yeasts biosensors into a new era where the biological element is optimized in a tailor-made fashion by in silico design and where the output signals can be recorded or followed on a smartphone.
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Affiliation(s)
- Helene Martin-Yken
- Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), UMR 792 Toulouse Biotechnology Institute (TBI), 31400 Toulouse, France; ; Tel.: +689-89-52-31-88
- Institut de Recherche pour le Développement (IRD), Faa’a, 98702 Tahiti, French Polynesia
- Unite Mixte de Recherche n°241 Ecosystemes Insulaires et Oceaniens, Université de la Polynésie Française, Faa’a, 98702 Tahiti, French Polynesia
- Laboratoire de Recherche sur les Biotoxines Marines, Institut Louis Malardé, Papeete, 98713 Tahiti, French Polynesia
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6
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Heinisch JJ. How to study intertwined and autoregulated eukaryotic signal transduction pathways. FEBS J 2020; 287:4844-4847. [PMID: 32246816 DOI: 10.1111/febs.15298] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Accepted: 03/17/2020] [Indexed: 11/30/2022]
Abstract
Mitogen-activated protein kinase (MAPK) pathways are a major means of eukaryotic cells to adapt to environmental changes, in the case of microorganisms, and to nutritional and hormonal signals, in the case of multicellular organisms. Numerous defects in such architecturally conserved pathways have been associated with different human cancers. These signaling cascades usually commence with sensors located in the plasma membrane, which through specific protein kinases activate a conserved tripartite MAPK module. Phosphorylation of their targets, that is, cytosolic proteins and/or transcription factors, then triggers the proper cellular response. In the model yeast Saccharomyces cerevisiae and other fungi, the cell wall integrity pathway (CWI) has been extensively studied and its components may serve as targets for antifungal drugs of clinical and agricultural importance. Another well-known MAPK cascade, the high osmolarity glycerol (HOG) pathway, is required to cope with osmotic stress. In the past decade, it has become increasingly evident that such pathways do not act in a linear top-down fashion, but are highly regulated by internal feedback mechanisms as well as by cross-pathway interactions. The work of Jiménez-Gutiérrez et al. in this issue provides an elegant way to identify new players in these complex networks. Comment on: https://doi.org/10.1111/febs.15288.
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Affiliation(s)
- Jürgen J Heinisch
- Department of Biology and Chemistry, Genetics Group, University of Osnabrück, Germany
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Lipid Biosynthesis as an Antifungal Target. J Fungi (Basel) 2018; 4:jof4020050. [PMID: 29677130 PMCID: PMC6023442 DOI: 10.3390/jof4020050] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 04/17/2018] [Accepted: 04/18/2018] [Indexed: 12/15/2022] Open
Abstract
Lipids, commonly including phospholipids, sphingolipids, fatty acids, sterols, and triacylglycerols (TAGs), are important biomolecules for the viability of all cells. Phospholipids, sphingolipids, and sterols are important constituents of biological membranes. Many lipids play important roles in the regulation of cell metabolism by acting as signaling molecules. Neutral lipids, including TAGs and sterol esters (STEs), are important storage lipids in cells. In view of the importance of lipid molecules, this review briefly summarizes the metabolic pathways for sterols, phospholipids, sphingolipids, fatty acids, and neutral lipids in fungi and illustrates the differences between fungal and human (or other mammalian) cells, especially in relation to lipid biosynthetic pathways. These differences might provide valuable clues for us to find target proteins for novel antifungal drugs. In addition, the development of lipidomics technology in recent years has supplied us with a shortcut for finding new antifungal drug targets; this ability is important for guiding our research on pathogenic fungi.
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Heinisch JJ, Rodicio R. Protein kinase C in fungi—more than just cell wall integrity. FEMS Microbiol Rev 2017; 42:4562651. [DOI: 10.1093/femsre/fux051] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 10/19/2017] [Indexed: 11/13/2022] Open
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9
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Nomura W, Ito Y, Inoue Y. Role of phosphatidylserine in the activation of Rho1-related Pkc1 signaling in Saccharomyces cerevisiae. Cell Signal 2017; 31:146-153. [DOI: 10.1016/j.cellsig.2017.01.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 01/03/2017] [Indexed: 10/20/2022]
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10
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Rippert D, Backhaus K, Rodicio R, Heinisch JJ. Cell wall synthesis and central carbohydrate metabolism are interconnected by the SNF1/Mig1 pathway in Kluyveromyces lactis. Eur J Cell Biol 2017; 96:70-81. [DOI: 10.1016/j.ejcb.2016.12.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 12/21/2016] [Accepted: 12/22/2016] [Indexed: 11/12/2022] Open
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Kock C, Arlt H, Ungermann C, Heinisch JJ. Yeast cell wall integrity sensors form specific plasma membrane microdomains important for signalling. Cell Microbiol 2016; 18:1251-67. [DOI: 10.1111/cmi.12635] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Revised: 06/14/2016] [Accepted: 06/17/2016] [Indexed: 02/06/2023]
Affiliation(s)
- Christian Kock
- Universität Osnabrück; Fachbereich Biologie/Chemie, AG Genetik; 49076 Osnabrück Germany
| | - Henning Arlt
- Universität Osnabrück; Fachbereich Biologie/Chemie, AG Biochemie; 49076 Osnabrück Germany
| | - Christian Ungermann
- Universität Osnabrück; Fachbereich Biologie/Chemie, AG Biochemie; 49076 Osnabrück Germany
| | - Jürgen J. Heinisch
- Universität Osnabrück; Fachbereich Biologie/Chemie, AG Genetik; 49076 Osnabrück Germany
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12
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Heinisch JJ, Brandt R. Signaling pathways and posttranslational modifications of tau in Alzheimer's disease: the humanization of yeast cells. MICROBIAL CELL 2016; 3:135-146. [PMID: 28357346 DOI: 10.15698/mic2016.04.489] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
In the past decade, yeast have been frequently employed to study the molecular mechanisms of human neurodegenerative diseases, generally by means of heterologous expression of genes encoding the relevant hallmark proteins. However, it has become evident that substantial posttranslational modifications of many of these proteins are required for the development and progression of potentially disease relevant changes. This is exemplified by the neuronal tau proteins, which are critically involved in a class of neuro-degenerative diseases collectively called tauopathies and which includes Alz-heimer's disease (AD) as its most common representative. In the course of the disease, tau changes its phosphorylation state and becomes hyperphosphory-lated, gets truncated by proteolytic cleavage, is subject to O-glycosylation, sumoylation, ubiquitinylation, acetylation and some other modifications. This poses the important question, which of these posttranslational modifications are naturally occurring in the yeast model or can be reconstituted by heterol-ogous gene expression. Here, we present an overview on common modifica-tions as they occur in tau during AD, summarize their potential relevance with respect to disease mechanisms and refer to the native yeast enzyme orthologs capable to perform these modifications. We will also discuss potential approaches to humanize yeast in order to create modification patterns resembling the situation in mammalian cells, which could enhance the value of Saccharomyces cerevisiae and Kluyveromyces lactis as disease models.
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Affiliation(s)
- Jürgen J Heinisch
- Universität Osnabrück, Fachbereich Biologie/Chemie, AG Genetik, Barbarastr. 11, D-49076 Osnabrück, Germany
| | - Roland Brandt
- Universität Osnabrück, Fachbereich Biologie/Chemie, AG Neurobiologie, Barbarastr. 11, D-49076 Osnabrück, Germany
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13
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Heinisch JJ, Brandt R. Signaling pathways and posttranslational modifications of tau in Alzheimer's disease: the humanization of yeast cells. MICROBIAL CELL 2016. [PMID: 28357346 DOI: 10.15698/mic2016.04] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
In the past decade, yeast have been frequently employed to study the molecular mechanisms of human neurodegenerative diseases, generally by means of heterologous expression of genes encoding the relevant hallmark proteins. However, it has become evident that substantial posttranslational modifications of many of these proteins are required for the development and progression of potentially disease relevant changes. This is exemplified by the neuronal tau proteins, which are critically involved in a class of neuro-degenerative diseases collectively called tauopathies and which includes Alz-heimer's disease (AD) as its most common representative. In the course of the disease, tau changes its phosphorylation state and becomes hyperphosphory-lated, gets truncated by proteolytic cleavage, is subject to O-glycosylation, sumoylation, ubiquitinylation, acetylation and some other modifications. This poses the important question, which of these posttranslational modifications are naturally occurring in the yeast model or can be reconstituted by heterol-ogous gene expression. Here, we present an overview on common modifica-tions as they occur in tau during AD, summarize their potential relevance with respect to disease mechanisms and refer to the native yeast enzyme orthologs capable to perform these modifications. We will also discuss potential approaches to humanize yeast in order to create modification patterns resembling the situation in mammalian cells, which could enhance the value of Saccharomyces cerevisiae and Kluyveromyces lactis as disease models.
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Affiliation(s)
- Jürgen J Heinisch
- Universität Osnabrück, Fachbereich Biologie/Chemie, AG Genetik, Barbarastr. 11, D-49076 Osnabrück, Germany
| | - Roland Brandt
- Universität Osnabrück, Fachbereich Biologie/Chemie, AG Neurobiologie, Barbarastr. 11, D-49076 Osnabrück, Germany
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14
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Leng Y, Zhong S. The Role of Mitogen-Activated Protein (MAP) Kinase Signaling Components in the Fungal Development, Stress Response and Virulence of the Fungal Cereal Pathogen Bipolaris sorokiniana. PLoS One 2015; 10:e0128291. [PMID: 26011429 PMCID: PMC4443973 DOI: 10.1371/journal.pone.0128291] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Accepted: 04/27/2015] [Indexed: 11/22/2022] Open
Abstract
Mitogen-activated protein kinases (MAPKs) have been demonstrated to be involved in fungal development, sexual reproduction, pathogenicity and/or virulence in many filamentous plant pathogenic fungi, but genes for MAPKs in the fungal cereal pathogen Bipolaris sorokiniana have not been characterized. In this study, orthologues of three MAPK genes (CsSLT2, CsHOG1 and CsFUS3) and one MAPK kinase kinase (MAPKKK) gene (CsSTE11) were identified in the whole genome sequence of the B. sorokiniana isolate ND90Pr, and knockout mutants were generated for each of them. The ∆Csfus3 and ∆Csste11 mutants were defective in conidiation and formation of appressoria-like structures, showed hypersensitivity to oxidative stress and lost pathogenicity on non-wounded leaves of barley cv. Bowman. When inoculated on wounded leaves of Bowman, the ∆Csfus3 and ∆Csste11 mutants were reduced in virulence compared to the wild type. No morphological changes were observed in the ∆Cshog1 mutants in comparison with the wild type; however, they were slightly reduced in growth under oxidative stress and were hypersensitive to hyperosmotic stress. The ∆Cshog1 mutants formed normal appressoria-like structures but were reduced in virulence when inoculated on Bowman leaves. The ∆Csslt2 mutants produced more vegetative hyphae, had lighter pigmentation, were more sensitive to cell wall degrading enzymes, and were reduced in virulence on Bowman leaves, although they formed normal appressoria like the wild type. Root infection assays indicated that the ∆Cshog1 and ∆Csslt2 mutants were able to infect barley roots while the ∆Csfus3 and ∆Csste11 failed to cause any symptoms. However, no significant difference in virulence was observed for ∆Cshog1 mutants while ∆Csslt2 mutants showed significantly reduced virulence on barley roots in comparison with the wild type. Our results indicated that all of these MAPK and MAPKKK genes are involved in the regulation of fungal development under normal and stress conditions and required for full virulence on barley plants.
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Affiliation(s)
- Yueqiang Leng
- Department of Plant Pathology, North Dakota State University, Fargo, North Dakota, United States of America
| | - Shaobin Zhong
- Department of Plant Pathology, North Dakota State University, Fargo, North Dakota, United States of America
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15
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Schmitz HP, Jendretzki A, Wittland J, Wiechert J, Heinisch JJ. Identification of Dck1 and Lmo1 as upstream regulators of the small GTPase Rho5 inSaccharomyces cerevisiae. Mol Microbiol 2015; 96:306-24. [DOI: 10.1111/mmi.12937] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/14/2015] [Indexed: 12/29/2022]
Affiliation(s)
- Hans-Peter Schmitz
- Faculty of Biology/Chemistry, Department of Genetics Barbarastr. 11; University of Osnabrueck; Osnabrueck D-49076 Germany
| | - Arne Jendretzki
- Faculty of Biology/Chemistry, Department of Genetics Barbarastr. 11; University of Osnabrueck; Osnabrueck D-49076 Germany
| | - Janina Wittland
- Faculty of Biology/Chemistry, Department of Genetics Barbarastr. 11; University of Osnabrueck; Osnabrueck D-49076 Germany
| | - Johanna Wiechert
- Faculty of Biology/Chemistry, Department of Genetics Barbarastr. 11; University of Osnabrueck; Osnabrueck D-49076 Germany
| | - Jürgen J. Heinisch
- Faculty of Biology/Chemistry, Department of Genetics Barbarastr. 11; University of Osnabrueck; Osnabrueck D-49076 Germany
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16
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Up against the wall: is yeast cell wall integrity ensured by mechanosensing in plasma membrane microdomains? Appl Environ Microbiol 2014; 81:806-11. [PMID: 25398859 DOI: 10.1128/aem.03273-14] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Yeast cell wall integrity (CWI) signaling serves as a model of the regulation of fungal cell wall synthesis and provides the basis for the development of antifungal drugs. A set of five membrane-spanning sensors (Wsc1 to Wsc3, Mid2, and Mtl1) detect cell surface stress and commence the signaling pathway upon perturbations of either the cell wall structure or the plasma membrane. We here summarize the latest advances in the structure/function relationship primarily of the Wsc1 sensor and critically review the evidence that it acts as a mechanosensor. The relevance and physiological significance of the information obtained for the function of the other CWI sensors, as well as expected future developments, are discussed.
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17
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Moretti M, Rossi M, Ciuffo M, Turina M. Functional characterization of the three mitogen-activated protein kinase kinases (MAP2Ks) present in the Cryphonectria parasitica genome reveals the necessity of Cpkk1 and Cpkk2, but not Cpkk3, for pathogenesis on chestnut (Castanea spp.). MOLECULAR PLANT PATHOLOGY 2014; 15:500-12. [PMID: 24373159 PMCID: PMC6638907 DOI: 10.1111/mpp.12111] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The biological function(s) of the cpkk1, cpkk2 and cpkk3 genes, encoding the three mitogen-activated protein kinase kinases (MAP2Ks) of Cryphonectria parasitica, the causal agent of chestnut blight, were examined through knockout strains. Cpkk1, the Mkk1 orthologue, acts in a phosphorylation cascade essential for cell integrity; Cpkk2 is the Ste7 orthologue involved in the pheromone response pathway; Cpkk3 is the Pbs2 orthologue, the MAP2K activated during the high-osmolarity response. Our analysis confirmed the role of each MAP2K in its respective signalling cascade with some peculiarities: abnormal hyphae with a reduced number of septa and thinner cell walls were observed in Δcpkk1 mutants, and a strong growth defect on solid media was evident in Δcpkk2 mutants, when compared with the controls. Virulence on chestnut was affected in both the Δcpkk1 and Δcpkk2 strains, which were also unable to complete the developmental steps essential for mating. No alterations were reported in Δcpkk3, except under hyperosmotic conditions and in the presence of fludioxonil. Δcpkk2 mutants, however, showed higher sensitivity during growth in medium containing the antibiotic G418 (Geneticin).
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Affiliation(s)
- Marino Moretti
- Istituto di Virologia Vegetale, CNR, Strada delle Cacce 73, 10135, Torino, Italy
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18
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Yun Y, Liu Z, Zhang J, Shim WB, Chen Y, Ma Z. The MAPKK FgMkk1 ofFusarium graminearumregulates vegetative differentiation, multiple stress response, and virulence via the cell wall integrity and high-osmolarity glycerol signaling pathways. Environ Microbiol 2013; 16:2023-37. [DOI: 10.1111/1462-2920.12334] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2013] [Accepted: 11/07/2013] [Indexed: 11/30/2022]
Affiliation(s)
- Yingzi Yun
- Institute of Biotechnology; Zhejiang University; 866 Yuhangtang Road Hangzhou 310058 China
| | - Zunyong Liu
- Institute of Biotechnology; Zhejiang University; 866 Yuhangtang Road Hangzhou 310058 China
| | - Jingze Zhang
- Institute of Biotechnology; Zhejiang University; 866 Yuhangtang Road Hangzhou 310058 China
| | - Won-Bo Shim
- Department of Plant Pathology and Microbiology; Texas A&M University; College Station TX USA
| | - Yun Chen
- Institute of Biotechnology; Zhejiang University; 866 Yuhangtang Road Hangzhou 310058 China
| | - Zhonghua Ma
- Institute of Biotechnology; Zhejiang University; 866 Yuhangtang Road Hangzhou 310058 China
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19
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Mutations in SNF1 complex genes affect yeast cell wall strength. Eur J Cell Biol 2013; 92:383-95. [DOI: 10.1016/j.ejcb.2014.01.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Revised: 12/19/2013] [Accepted: 01/02/2014] [Indexed: 01/01/2023] Open
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20
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Francois JM, Formosa C, Schiavone M, Pillet F, Martin-Yken H, Dague E. Use of atomic force microscopy (AFM) to explore cell wall properties and response to stress in the yeast Saccharomyces cerevisiae. Curr Genet 2013; 59:187-96. [PMID: 24071902 DOI: 10.1007/s00294-013-0411-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 09/12/2013] [Accepted: 09/18/2013] [Indexed: 11/30/2022]
Abstract
Over the past 20 years, the yeast cell wall has been thoroughly investigated by genetic and biochemical methods, leading to remarkable advances in the understanding of its biogenesis and molecular architecture as well as to the mechanisms by which this organelle is remodeled in response to environmental stresses. Being a dynamic structure that constitutes the frontier between the cell interior and its immediate surroundings, imaging cell surface, measuring mechanical properties of cell wall or probing cell surface proteins for localization or interaction with external biomolecules are among the most burning questions that biologists wished to address in order to better understand the structure-function relationships of yeast cell wall in adhesion, flocculation, aggregation, biofilm formation, interaction with antifungal drugs or toxins, as well as response to environmental stresses, such as temperature changes, osmotic pressure, shearing stress, etc. The atomic force microscopy (AFM) is nowadays the most qualified and developed technique that offers the possibilities to address these questions since it allows working directly on living cells to explore and manipulate cell surface properties at nanometer resolution and to analyze cell wall proteins at the single molecule level. In this minireview, we will summarize the most recent contributions made by AFM in the analysis of the biomechanical and biochemical properties of the yeast cell wall and illustrate the power of this tool to unravel unexpected effects caused by environmental stresses and antifungal agents on the surface of living yeast cells.
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Affiliation(s)
- Jean Marie Francois
- Université de Toulouse, INSA, UPS, INP, 135 avenue de Rangueil, 31077, Toulouse, France,
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21
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Cruz S, Muñoz S, Manjón E, García P, Sanchez Y. The fission yeast cell wall stress sensor-like proteins Mtl2 and Wsc1 act by turning on the GTPase Rho1p but act independently of the cell wall integrity pathway. Microbiologyopen 2013; 2:778-94. [PMID: 23907979 PMCID: PMC3831639 DOI: 10.1002/mbo3.113] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Revised: 06/07/2013] [Accepted: 06/11/2013] [Indexed: 12/27/2022] Open
Abstract
Sensing stressful conditions that affect the cell wall reorganization is important for yeast survival. Here, we studied two proteins SpWsc1p and SpMtl2p with structural features indicative of plasma membrane-associated cell wall sensors. We found that Mtl2p and Wsc1p act by turning on the Rho1p GTPase. Each gene could be deleted individually without affecting viability, but the deletion of both was lethal and this phenotype was rescued by overexpression of the genes encoding either Rho1p or its GDP/GTP exchange factors (GEFs). In addition, wsc1Δ and mtl2Δ cells showed a low level of Rho1p-GTP under cell wall stress. Mtl2p-GFP (green fluorescent protein) localized to the cell periphery and was necessary for survival under different types of cell wall stress. Wsc1p-GFP was concentrated in patches at the cell tips, it interacted with the Rho-GEF Rgf2p, and its overexpression activated cell wall biosynthesis. Our results are consistent with the notion that cell wall assembly is regulated by two different networks involving Rho1p. One includes signaling from Mtl2p through Rho1p to Pck1p, while the second one implicates signaling from Wsc1p and Rgf2p through Rho1p to activate glucan synthase (GS). Finally, signaling through the mitogen-activated protein kinase (MAPK) Pmk1p remained active in mtl2Δ and wsc1Δ disruptants exposed to cell wall stress, suggesting that the cell wall stress-sensing spectrum of Schizosaccharomyces pombe sensor-like proteins differs from that of Saccharomyces cerevisiae.
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Affiliation(s)
- Sandra Cruz
- Instituto de Biología Funcional y Genómica, CSIC/Universidad de Salamanca and Departamento de Microbiología y Genética, Universidad de Salamanca, C/Zacarías González s/n., Salamanca, Spain
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22
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Rodicio R, Heinisch JJ. Yeast on the milky way: genetics, physiology and biotechnology of Kluyveromyces lactis. Yeast 2013; 30:165-77. [PMID: 23576126 DOI: 10.1002/yea.2954] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2013] [Revised: 03/08/2013] [Accepted: 03/12/2013] [Indexed: 11/08/2022] Open
Abstract
The milk yeast Kluyveromyces lactis has a life cycle similar to that of Saccharomyces cerevisiae and can be employed as a model eukaryote using classical genetics, such as the combination of desired traits, by crossing and tetrad analysis. Likewise, a growing set of vectors, marker cassettes and tags for fluorescence microscopy are available for manipulation by genetic engineering and investigating its basic cell biology. We here summarize these applications, as well as the current knowledge regarding its central metabolism, glucose and extracellular stress signalling pathways. A short overview on the biotechnological potential of K. lactis concludes this review.
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Affiliation(s)
- Rosaura Rodicio
- Departamento de Bioquímica y Biología Molecular and Instituto Universitario de Biotecnología de Asturias, Universidad de Oviedo, Spain
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23
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Mascaraque V, Hernáez ML, Jiménez-Sánchez M, Hansen R, Gil C, Martín H, Cid VJ, Molina M. Phosphoproteomic analysis of protein kinase C signaling in Saccharomyces cerevisiae reveals Slt2 mitogen-activated protein kinase (MAPK)-dependent phosphorylation of eisosome core components. Mol Cell Proteomics 2012; 12:557-74. [PMID: 23221999 DOI: 10.1074/mcp.m112.020438] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The cell wall integrity (CWI) pathway of the model organism Saccharomyces cerevisiae has been thoroughly studied as a paradigm of the mitogen-activated protein kinase (MAPK) pathway. It consists of a classic MAPK module comprising the Bck1 MAPK kinase kinase, two redundant MAPK kinases (Mkk1 and Mkk2), and the Slt2 MAPK. This module is activated under a variety of stimuli related to cell wall homeostasis by Pkc1, the only member of the protein kinase C family in budding yeast. Quantitative phosphoproteomics based on stable isotope labeling of amino acids in cell culture is a powerful tool for globally studying protein phosphorylation. Here we report an analysis of the yeast phosphoproteome upon overexpression of a PKC1 hyperactive allele that specifically activates CWI MAPK signaling in the absence of external stimuli. We found 82 phosphopeptides originating from 43 proteins that showed enhanced phosphorylation in these conditions. The MAPK S/T-P target motif was significantly overrepresented in these phosphopeptides. Hyperphosphorylated proteins provide putative novel targets of the Pkc1-cell wall integrity pathway involved in diverse functions such as the control of gene expression, protein synthesis, cytoskeleton maintenance, DNA repair, and metabolism. Remarkably, five components of the plasma-membrane-associated protein complex known as eisosomes were found among the up-regulated proteins. We show here that Pkc1-induced phosphorylation of the eisosome core components Pil1 and Lsp1 was not exerted directly by Pkc1, but involved signaling through the Slt2 MAPK module.
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Affiliation(s)
- Victoria Mascaraque
- Departamento de Microbiología II, Facultad de Farmacia, Universidad Complutense de Madrid and Instituto Ramón y Cajal de Investigaciones Sanitarias (IRYCIS), Plaza de Ramón y Cajal s/n, Madrid, Spain
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24
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Dupres V, Heinisch JJ, Dufrêne YF. Atomic force microscopy demonstrates that disulfide bridges are required for clustering of the yeast cell wall integrity sensor Wsc1. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:15129-15134. [PMID: 22107047 DOI: 10.1021/la203679s] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
In yeasts, cell surface stresses are detected by a family of plasma membrane sensors. Among these, Wsc1 contains an extracellular cysteine-rich domain (CRD), which mediates sensor clustering and is believed to anchor the sensor in the cell wall. Although the formation of Wsc1 clusters and their interaction with the intracellular pathway components are important for proper stress signaling, the molecular mechanisms underlying clustering remain poorly understood. Here, we used the combination of single-molecule atomic force microscopy (AFM) with genetic manipulations to demonstrate that Wsc1 clustering involves disulfide bridges of the CRD. Using AFM tips carrying nitrilotriacetate groups, we mapped the distribution of individual His-tagged sensors on living yeast cells. While Wsc1 formed nanoscale clusters on native cells, clustering was no longer observed after treatment with the reducing agent dithiothreitol (DTT), indicating that intra- or intermolecular disulfide bridges are required for clustering. Moreover, DTT treatment resulted in a significant increase in cell surface roughness, suggesting that disulfide bridges between other cell-wall proteins are crucial for proper cell surface topology. The remarkable sensor properties unravelled here may well apply to other sensors and receptors with cysteine-rich domains throughout biology. Our combined method of AFM with genetic manipulations offers great prospects to explore the mechanisms underlying the clustering of cell surface proteins.
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Affiliation(s)
- Vincent Dupres
- Institute of Condensed Matter and Nanosciences, Université Catholique de Louvain, Place Croix du Sud 1, B-1348 Louvain-la-Neuve, Belgium
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25
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New azole antifungal agents with novel modes of action: Synthesis and biological studies of new tridentate ligands based on pyrazole and triazole. Eur J Med Chem 2011; 46:4117-24. [DOI: 10.1016/j.ejmech.2011.06.012] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2011] [Revised: 06/09/2011] [Accepted: 06/09/2011] [Indexed: 11/18/2022]
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26
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Milk and sugar: Regulation of cell wall synthesis in the milk yeast Kluyveromyces lactis. Eur J Cell Biol 2011; 90:745-50. [DOI: 10.1016/j.ejcb.2011.04.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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27
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Arias P, Díez-Muñiz S, García R, Nombela C, Rodríguez-Peña JM, Arroyo J. Genome-wide survey of yeast mutations leading to activation of the yeast cell integrity MAPK pathway: novel insights into diverse MAPK outcomes. BMC Genomics 2011; 12:390. [PMID: 21810245 PMCID: PMC3167797 DOI: 10.1186/1471-2164-12-390] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Accepted: 08/02/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The yeast cell wall integrity mitogen-activated protein kinase (CWI-MAPK) pathway is the main regulator of adaptation responses to cell wall stress in yeast. Here, we adopt a genomic approach to shed light on two aspects that are only partially understood, namely, the characterization of the gene functional catalog associated with CWI pathway activation and the extent to which MAPK activation correlates with transcriptional outcomes. RESULTS A systematic yeast mutant deletion library was screened for constitutive transcriptional activation of the CWI-related reporter gene MLP1. Monitoring phospho-Slt2/Mpk1 levels in the identified mutants revealed sixty-four deletants with high levels of phosphorylation of this MAPK, including mainly genes related to cell wall construction and morphogenesis, signaling, and those with unknown function. Phenotypic analysis of the last group of mutants suggests their involvement in cell wall homeostasis. A good correlation between levels of Slt2 phosphorylation and the magnitude of the transcriptional response was found in most cases. However, the expression of CWI pathway-related genes was enhanced in some mutants in the absence of significant Slt2 phosphorylation, despite the fact that functional MAPK signaling through the pathway was required. CWI pathway activation was associated to increased deposition of chitin in the cell wall - a known survival compensatory mechanism - in about 30% of the mutants identified. CONCLUSION We provide new insights into yeast genes related to the CWI pathway and into how the state of activation of the Slt2 MAPK leads to different outcomes, discovering the versatility of this kind of signaling pathways. These findings potentially have broad implications for understanding the functioning of other eukaryotic MAPKs.
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Affiliation(s)
- Patricia Arias
- Departamento de Microbiología II, Facultad de Farmacia, Universidad Complutense de Madrid, IRYCIS, 28040 Madrid, Spain
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28
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Bayram O, Braus GH. Coordination of secondary metabolism and development in fungi: the velvet family of regulatory proteins. FEMS Microbiol Rev 2011; 36:1-24. [PMID: 21658084 DOI: 10.1111/j.1574-6976.2011.00285.x] [Citation(s) in RCA: 376] [Impact Index Per Article: 28.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Filamentous fungi produce a number of small bioactive molecules as part of their secondary metabolism ranging from benign antibiotics such as penicillin to threatening mycotoxins such as aflatoxin. Secondary metabolism can be linked to fungal developmental programs in response to various abiotic or biotic external triggers. The velvet family of regulatory proteins plays a key role in coordinating secondary metabolism and differentiation processes such as asexual or sexual sporulation and sclerotia or fruiting body formation. The velvet family shares a protein domain that is present in most parts of the fungal kingdom from chytrids to basidiomycetes. Most of the current knowledge derives from the model Aspergillus nidulans where VeA, the founding member of the protein family, was discovered almost half a century ago. Different members of the velvet protein family interact with each other and the nonvelvet protein LaeA, primarily in the nucleus. LaeA is a methyltransferase-domain protein that functions as a regulator of secondary metabolism and development. A comprehensive picture of the molecular interplay between the velvet domain protein family, LaeA and other nuclear regulatory proteins in response to various signal transduction pathway starts to emerge from a jigsaw puzzle of several recent studies.
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Affiliation(s)
- Ozgür Bayram
- Institut für Mikrobiologie und Genetik, Abteilung Molekulare Mikrobiologie und Genetik, Georg-August-Universität Göttingen, Göttingen, Germany
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29
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Jendretzki A, Wittland J, Wilk S, Straede A, Heinisch JJ. How do I begin? Sensing extracellular stress to maintain yeast cell wall integrity. Eur J Cell Biol 2011; 90:740-4. [PMID: 21640429 DOI: 10.1016/j.ejcb.2011.04.006] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
The cell wall integrity (CWI) signalling pathway is necessary to remodel the yeast cell wall during normal morphogenesis and in response to cell surface stress. In the Baker's yeast Saccharomyces cerevisiae, a set of five membrane-spanning sensors, namely Wsc1, Wsc2, Wsc3, Mid2 and Mtl1, detect perturbations in the cell wall and/or the plasma membrane and activate a downstream signal transduction pathway with a central MAP kinase module. As a consequence, the expression of genes whose products are involved in cell wall structure and remodelling is induced. This review summarises our recent results on sensor structure and function, as well as the advances made regarding sensor mechanics.
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Affiliation(s)
- Arne Jendretzki
- University of Osnabrück, Faculty of Biology and Chemistry, Department of Genetics, Barbarastrasse 11, 49076 Osnabrück, Germany
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30
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Baxter BK, DiDone L, Ogu D, Schor S, Krysan DJ. Identification, in vitro activity and mode of action of phosphoinositide-dependent-1 kinase inhibitors as antifungal molecules. ACS Chem Biol 2011; 6:502-10. [PMID: 21294551 DOI: 10.1021/cb100399x] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Although protein kinases have recently emerged as important drug targets, the anti-infective potential of protein kinase inhibitors has not been developed extensively. We identified the mammalian PDK1 inhibitor KP-372-1 as a potent antifungal molecule with activity against yeast and fungal biofilms using a screening strategy for protein kinase inhibitors that block the cell wall stress response in yeast. Genetic and biochemical studies indicate that KP-372-1 inhibits fungal PDK1 orthologs (Pkh kinases) as part of its mode of action and support a role for Pkh kinases in eisosome assembly. Two other structurally distinct molecules that inhibit PDK1, OSU-03012 and UCN-01, also have antifungal activity. Taken together, these data indicate that fungal PDK1 orthologs are promising targets for new antifungal drug development.
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Affiliation(s)
- Bonnie K. Baxter
- Department of Pediatrics and ‡Department of Microbiology/Immunology, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642, United States
| | - Louis DiDone
- Department of Pediatrics and ‡Department of Microbiology/Immunology, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642, United States
| | - Duana Ogu
- Department of Pediatrics and ‡Department of Microbiology/Immunology, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642, United States
| | - Stanford Schor
- Department of Pediatrics and ‡Department of Microbiology/Immunology, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642, United States
| | - Damian J. Krysan
- Department of Pediatrics and ‡Department of Microbiology/Immunology, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642, United States
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31
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LaFayette SL, Collins C, Zaas AK, Schell WA, Betancourt-Quiroz M, Gunatilaka AAL, Perfect JR, Cowen LE. PKC signaling regulates drug resistance of the fungal pathogen Candida albicans via circuitry comprised of Mkc1, calcineurin, and Hsp90. PLoS Pathog 2010; 6:e1001069. [PMID: 20865172 PMCID: PMC2928802 DOI: 10.1371/journal.ppat.1001069] [Citation(s) in RCA: 235] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2010] [Accepted: 07/26/2010] [Indexed: 11/25/2022] Open
Abstract
Fungal pathogens exploit diverse mechanisms to survive exposure to antifungal drugs. This poses concern given the limited number of clinically useful antifungals and the growing population of immunocompromised individuals vulnerable to life-threatening fungal infection. To identify molecules that abrogate resistance to the most widely deployed class of antifungals, the azoles, we conducted a screen of 1,280 pharmacologically active compounds. Three out of seven hits that abolished azole resistance of a resistant mutant of the model yeast Saccharomyces cerevisiae and a clinical isolate of the leading human fungal pathogen Candida albicans were inhibitors of protein kinase C (PKC), which regulates cell wall integrity during growth, morphogenesis, and response to cell wall stress. Pharmacological or genetic impairment of Pkc1 conferred hypersensitivity to multiple drugs that target synthesis of the key cell membrane sterol ergosterol, including azoles, allylamines, and morpholines. Pkc1 enabled survival of cell membrane stress at least in part via the mitogen activated protein kinase (MAPK) cascade in both species, though through distinct downstream effectors. Strikingly, inhibition of Pkc1 phenocopied inhibition of the molecular chaperone Hsp90 or its client protein calcineurin. PKC signaling was required for calcineurin activation in response to drug exposure in S. cerevisiae. In contrast, Pkc1 and calcineurin independently regulate drug resistance via a common target in C. albicans. We identified an additional level of regulatory control in the C. albicans circuitry linking PKC signaling, Hsp90, and calcineurin as genetic reduction of Hsp90 led to depletion of the terminal MAPK, Mkc1. Deletion of C. albicans PKC1 rendered fungistatic ergosterol biosynthesis inhibitors fungicidal and attenuated virulence in a murine model of systemic candidiasis. This work establishes a new role for PKC signaling in drug resistance, novel circuitry through which Hsp90 regulates drug resistance, and that targeting stress response signaling provides a promising strategy for treating life-threatening fungal infections. Treating fungal infections is challenging due to the emergence of drug resistance and the limited number of clinically useful antifungal drugs. We screened a library of 1,280 pharmacologically active compounds to identify those that reverse resistance of the leading human fungal pathogen, Candida albicans, to the most widely used antifungals, the azoles. This revealed a new role for protein kinase C (PKC) signaling in resistance to drugs targeting the cell membrane, including azoles, allylamines, and morpholines. We dissected mechanisms through which PKC regulates resistance in C. albicans and the model yeast Saccharomyces cerevisiae. PKC enabled survival of cell membrane stress at least in part through the mitogen-activated protein kinase (MAPK) cascade in both species. In S. cerevisiae, inhibition of PKC signaling blocked activation of a key regulator of membrane stress responses, calcineurin. In C. albicans, Pkc1 and calcineurin independently regulate resistance via a common target. Deletion of C. albicans PKC1 rendered fungistatic drugs fungicidal and reduced virulence in a mouse model. The molecular chaperone Hsp90, which stabilizes client proteins including calcineurin, also stabilized the terminal C. albicans MAPK, Mkc1. We establish new circuitry connecting PKC with Hsp90 and calcineurin and suggest a promising strategy for treating life-threatening fungal infections.
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Affiliation(s)
| | - Cathy Collins
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Aimee K. Zaas
- Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Wiley A. Schell
- Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Marisol Betancourt-Quiroz
- Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America
| | - A. A. Leslie Gunatilaka
- SW Center for Natural Products Research & Commercialization, Office of Arid Lands Studies, The University of Arizona, Tucson, Arizona, United States of America
| | - John R. Perfect
- Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Leah E. Cowen
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- * E-mail:
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Dague E, Bitar R, Ranchon H, Durand F, Yken HM, François JM. An atomic force microscopy analysis of yeast mutants defective in cell wall architecture. Yeast 2010; 27:673-84. [DOI: 10.1002/yea.1801] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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33
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Li R, Xiong G, Zhang B, Zhou Y. Rice plants response to the disruption of OsCSLD4 gene. PLANT SIGNALING & BEHAVIOR 2010; 5:136-9. [PMID: 20110776 PMCID: PMC2884116 DOI: 10.4161/psb.5.2.10369] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The plant cell wall is a complex polysaccharide network and performs important developmental and physiological functions far beyond supplying the physical constrains. Plant cells have the ability to react to cell wall defects as exhibited by changes in gene expression, accumulation of ectopic lignin, stress responses and growth arrest. It is a major challenge to understand how plants sense and respond to wall integrity since very little is known about the signaling involved in the responses. Cellulose synthase-like D (CSLD) proteins mediating the biosynthesis of a wall polysaccharide polymer make up a common subfamily to all plants. Recently, we have reported the functional characterization of CSLD4 in rice. Mutations in OsCSLD4 show morphological alterations and pleiotropic effects on wall compositions and structure. Our study demonstrates that OsCSLD4 play a critical role in cell wall formation and plant growth. Here we show the subtle wall alterations by separating the culm residues into five fractions. Quantitative RT-PCR analysis further revealed that the expression of various genes involved in xylan synthesis and cell cycle regulation was altered in mutant plants, as the responses to OsCSLD4 disruption. Therefore, plants may have fine sensory machinery to react to wall defects and modulate growth for adapting to the changes.
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Affiliation(s)
- Rui Li
- National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
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Zhou J, Zhong Q, Li G, Greenberg ML. Loss of cardiolipin leads to longevity defects that are alleviated by alterations in stress response signaling. J Biol Chem 2009; 284:18106-14. [PMID: 19401462 DOI: 10.1074/jbc.m109.003236] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Perturbation of cardiolipin (CL) synthesis in yeast cells leads to defective respiratory chain function and mitochondrial DNA loss, both of which have been implicated in aging in mammals. The availability of yeast CL mutants enabled us to directly investigate the role of CL synthesis in aging. In this report, we show that the replicative life span of pgs1Delta, which lacks both CL and the precursor phosphatidylglycerol (PG), was significantly decreased at 30 degrees C. The life span of crd1Delta, which has PG but not CL, was unaffected at 30 degrees C but reduced at 37 degrees C. Life span extension induced by calorie restriction was not affected by the loss of CL. However, mild heat and osmotic stress, which extend life span in wild type cells, did not increase longevity in CL mutants, suggesting that the stress response is perturbed in these mutants. Consistent with this, longevity defects in pgs1Delta were alleviated by down-regulation of the high osmolarity glycerol stress response pathway, as well as by promoting cell integrity with the osmotic stabilizer sorbitol or via genetic suppression with the kre5(W1166X) mutant. These findings show for the first time that perturbation of CL synthesis leads to decreased longevity in yeast, which is restored by altering signaling through stress response pathways.
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Affiliation(s)
- Jingming Zhou
- Department of Biological Sciences, Wayne State University, Detroit, Michigan 48202, USA
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35
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Heinisch JJ. Baker's yeast as a tool for the development of antifungal drugs which target cell integrity – an update. Expert Opin Drug Discov 2008; 3:931-43. [DOI: 10.1517/17460441.3.8.931] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Jürgen J Heinisch
- Universität Osnabrück, Fachbereich Biologie/Chemie, AG Genetik, Barbarastr. 11, D-49076 Osnabrück, Germany ;
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Hutzler F, Gerstl R, Lommel M, Strahl S. Protein N-glycosylation determines functionality of the Saccharomyces cerevisiae cell wall integrity sensor Mid2p. Mol Microbiol 2008; 68:1438-49. [PMID: 18410496 DOI: 10.1111/j.1365-2958.2008.06243.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The fungal cell wall is a highly dynamic structure that is essential to maintain cell shape and stability. Hence in yeasts and fungi cell wall integrity is tightly controlled. The Saccharomyces cerevisiae plasma membrane protein Mid2p is a putative mechanosensor that responds to cell wall stresses and morphological changes during pheromone induction. The extracellular domain of Mid2p, which is crucial to sensing, is highly O- and N-glycosylated. We showed that O-mannosylation is determining stability of Mid2p. If and how N-glycosylation is linked to Mid2p function was unknown. Here we demonstrate that Mid2p contains a single high mannose N-linked glycan at position Asn-35. The N-glycan is located close to the N-terminus and is exposed from the plasma membrane towards the cell wall through a highly O-mannosylated domain that is predicted to adopt a rod-like conformation. In contrast to O-mannosylation, lack of the N-linked glycan affects neither, stability of Mid2p nor distribution at the plasma membrane during vegetative and sexual growth. However, non-N-glycosylated Mid2p fails to perceive cell wall challenges. Our data further demonstrate that both the extent of the N-linked glycan and its distance from the plasma membrane affect Mid2p function, suggesting the N-glycan to be directly involved in Mid2p sensing.
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Affiliation(s)
- Franziska Hutzler
- Heidelberg Institute of Plant Science, Department V Cell Chemistry, Ruprecht-Karls-University Heidelberg, Im Neuenheimer Feld 360, D-69120 Heidelberg, Germany
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Rodriguez-Peña JM, Diez-Muñiz S, Nombela C, Arroyo J. A yeast strain biosensor to detect cell wall-perturbing agents. J Biotechnol 2007; 133:311-7. [PMID: 18055054 DOI: 10.1016/j.jbiotec.2007.10.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2007] [Revised: 10/11/2007] [Accepted: 10/23/2007] [Indexed: 01/12/2023]
Abstract
The cell wall is an essential, unique and highly conserved structure in fungi, thus representing an ideal set of targets for antifungal drugs. In the model yeast S. cerevisiae, the Pkc1-mediated cell integrity signalling pathway is essential for maintenance of the cell wall. Adaptation to cell wall stress involves the transcriptional activation of genes functionally relevant for cell wall remodelling. One of these activated genes, namely MLP1/YKL161c, is an ideal indicator of cell wall perturbations, Mlp1p, being almost undetectable under normal growth conditions, accumulated in large amounts when cell wall integrity was compromised. We have developed a reporter system based on the expression of the nourseothricin resistance gene under the control of the regulatory sequences of MLP1. Yeast cells transformed with this reporter construct, subjected to a cell wall stress, by chemical agents present in the culture medium, attained a high level of nourseothricin-resistance with respect to non-stressed cells, as a consequence of increased MLP1 expression. A genetically modified S. cerevisiae strain (AT-1) including the reporter system integrated into the native MLP1 chromosomal locus was also developed. This strain was tested against several compounds, grouping different mechanisms of yeast growth inhibition, responding specifically to cell wall-perturbing agents. Our results demonstrate the usefulness and feasibility of the AT-1 strain as a biosensor to perform high-throughput antifungal screenings for the identification of antifungal compounds active on the cell wall.
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Affiliation(s)
- Jose M Rodriguez-Peña
- Departamento de Microbiología II, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain.
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Zhao X, Mehrabi R, Xu JR. Mitogen-activated protein kinase pathways and fungal pathogenesis. EUKARYOTIC CELL 2007; 6:1701-14. [PMID: 17715363 PMCID: PMC2043402 DOI: 10.1128/ec.00216-07] [Citation(s) in RCA: 263] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Xinhua Zhao
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA
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Hématy K, Sado PE, Van Tuinen A, Rochange S, Desnos T, Balzergue S, Pelletier S, Renou JP, Höfte H. A receptor-like kinase mediates the response of Arabidopsis cells to the inhibition of cellulose synthesis. Curr Biol 2007; 17:922-31. [PMID: 17540573 DOI: 10.1016/j.cub.2007.05.018] [Citation(s) in RCA: 341] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2007] [Revised: 04/22/2007] [Accepted: 05/03/2007] [Indexed: 10/23/2022]
Abstract
BACKGROUND A major challenge is to understand how the walls of expanding plant cells are correctly assembled and remodeled, often in the presence of wall-degrading micro-organisms. Plant cells, like yeast, react to cell-wall perturbations as shown by changes in gene expression, accumulation of ectopic lignin, and growth arrest caused by the inhibition of cellulose synthesis. RESULTS We have identified a plasma-membrane-bound receptor-like kinase (THESEUS1), which is present in elongating cells. Mutations in THE1 and overexpression of a functional THE1-GFP fusion protein did not affect wild-type (WT) plants but respectively attenuated and enhanced growth inhibition and ectopic lignification in seedlings mutated in cellulose synthase CESA6 without influencing the cellulose deficiency. A T-DNA insertion mutant for THE1 also attenuated the growth defect and ectopic-lignin production in other but not all cellulose-deficient mutants. The deregulation of a small number of genes in cesA6 mutants depended on the presence of THE1. Some of these genes are involved in pathogen defense, in wall crosslinking, or in protecting the cell against reactive oxygen species. CONCLUSIONS The results show that THE1 mediates the response of growing plant cells to the perturbation of cellulose synthesis and may act as a cell-wall-integrity sensor.
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Affiliation(s)
- Kian Hématy
- Laboratoire de Biologie Cellulaire, UR501, Institut Jean-Pierre Bourgin, Institut National de la Recherche Agronomique Centre de Versailles, Route de St Cyr, 78026 Versailles, France
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Straede A, Heinisch JJ. Functional analyses of the extra- and intracellular domains of the yeast cell wall integrity sensors Mid2 and Wsc1. FEBS Lett 2007; 581:4495-500. [PMID: 17761172 DOI: 10.1016/j.febslet.2007.08.027] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2007] [Revised: 07/12/2007] [Accepted: 08/13/2007] [Indexed: 11/18/2022]
Abstract
Cell wall integrity signalling in Saccharomyces cerevisiae provides a model for the regulation of fungal wall biosynthesis. Chimers of the major plasma membrane sensors Wsc1 and Mid2 fused to GFP have been employed to show that intracellular and membrane distribution is only dependent on a membrane-anchored cytoplasmic tail. Phenotypic analyses of chimeric sensors in an isogenic Deltamid2 Deltawsc1 double deletion strain indicate that this tail, provided that it is linked to an extracellular domain, also determines the cellular response to different surface stresses to a large extent.
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Affiliation(s)
- Andrea Straede
- Universität Osnabrück, Fachbereich Biologie/Chemie, AG Genetik, Barbarastr. 11, D-49076 Osnabrück, Germany
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Rodicio R, Buchwald U, Schmitz HP, Heinisch JJ. Dissecting sensor functions in cell wall integrity signaling in Kluyveromyces lactis. Fungal Genet Biol 2007; 45:422-35. [PMID: 17827039 DOI: 10.1016/j.fgb.2007.07.009] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2007] [Revised: 07/24/2007] [Accepted: 07/25/2007] [Indexed: 10/23/2022]
Abstract
KlWSC1, KlWSC2/3 and KlMID2, which encode putative plasma membrane sensors for cell wall integrity signaling in Kluyveromyces lactis, were cloned and characterized. Double and triple deletion mutants show severe cell integrity defects, indicating overlapping functions. The Klwsc1 Klmid2 double deletion phenotype can be suppressed by overexpression of the downstream components KlROM2, KlPKC1 and KlBCK1. KlWsc1 sensor domain analyses showed that an amino-terminal elongation as well as an extension within the cytoplasmic domain are dispensable for function. Heterologous complementation by KlMID2 and KlWSC1 in Saccharomyces cerevisiae is only achieved upon overexpression. In contrast to ScMID2, ScWSC1 complements in K. lactis. Functional studies with chimeric Mid2 constructs indicate that species specificity is mainly conferred by the extracellular domain. Sensor-GFP fusions localize to the plasma membrane, with a cell cycle dependent distribution of KlWsc1-GFP. Both Wsc-type sensors concentrate in discrete spots within the plasma membrane.
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Affiliation(s)
- Rosaura Rodicio
- Universität Osnabrück, Fachbereich Biologie/Chemie, AG Genetik, Barbarastr. 11, D-49076 Osnabrück, Germany
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Straede A, Corran A, Bundy J, Heinisch JJ. The effect of tea tree oil and antifungal agents on a reporter for yeast cell integrity signalling. Yeast 2007; 24:321-34. [PMID: 17397109 DOI: 10.1002/yea.1478] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Cell integrity in Saccharomyces cerevisiae is ensured by a rigid cell wall whose synthesis is controlled by a highly conserved MAP kinase signal transduction cascade. Stress at the cell surface is detected by a set of sensors and ultimately transmitted through this cascade to the transcription factor Rlm1, which governs expression of many genes encoding enzymes of cell wall biosynthesis. We here report on a number of versatile reporter constructs which link activation of a hybrid, Rlm1-lexA, by the MAP kinase Mpk1/Slt2 to the expression of the bacterial lacZ gene. This system was adapted to automated microwell screening and shown to be activated by a number of compounds inhibiting cell wall biosynthesis or interfering with plasma membrane function. In addition, we tested tea tree oil and two of its purified constituents (alpha-terpineol, terpinen-4-ol) for their effects on growth and on cell integrity signalling using such reporter strains. Tea tree oil was found to inhibit growth of wild-type and slg1/wsc1 mutant cells at a threshold of approximately 0.1% v/v, with the purified compounds acting already at half these concentrations. A mid2 deletion displayed hyper-resistance. Tea tree oil also induces the signalling pathway in a dose-dependent manner.
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Affiliation(s)
- Andrea Straede
- Universität Osnabrück, Fachbereich Biologie/Chemie, AG Genetik, Barbarastrasse 11, D-49076 Osnabrück, Germany
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Rodicio R, Koch S, Schmitz HP, Heinisch JJ. KlRHO1 and KlPKC1 are essential for cell integrity signalling in Kluyveromyces lactis. Microbiology (Reading) 2006; 152:2635-2649. [PMID: 16946259 DOI: 10.1099/mic.0.29105-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Cell integrity in yeasts is ensured by a rigid cell wall whose synthesis is triggered by a MAP kinase-mediated signal-transduction cascade. Upstream regulatory components of this pathway inSaccharomyces cerevisiaeinvolve a single protein kinase C, which is regulated by interaction with the small GTPase Rho1. Here, two genes were isolated which encode these proteins fromKluyveromyces lactis(KlPKC1andKlRHO1). Sequencing showed ORFs which encode proteins of 1161 and 208 amino acids, respectively. The deduced proteins shared 59 and 85 % overall amino acid identities, respectively, with their homologues fromS. cerevisiae. Null mutants in both genes were non-viable, as shown by tetrad analyses of the heterozygous diploid strains. Overexpression of theKlRHO1gene under the control of theScGAL1promoter severely impaired growth in bothS. cerevisiaeandK. lactis. On the other hand, a similar construct withKlPKC1did not show a pronounced phenotype. Two-hybrid analyses showed interaction between Rho1 and Pkc1 for theK. lactisproteins and theirS. cerevisiaehomologues. A green fluorescent protein (GFP) fusion to the C-terminal end of KlPkc1 located the protein to patches in the growing bud, and at certain stages of the division process also to the bud neck. N-terminal GFP fusions to KlRho1 localized mainly to the cell surface (presumably the cytoplasmic side of the plasma membrane) and to the vacuole, with some indications of traffic from the former to the latter. Thus, KlPkc1 and KlRho1 have been shown to serve vital functions inK. lactis, to interact in cell integrity signalling and to traffic between the plasma membrane and the vacuole.
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Affiliation(s)
- Rosaura Rodicio
- Departamento de Bioquímica y Biología Molecular, Universidad de Oviedo, 33006 Oviedo, Spain
- Universität Osnabrück, Fachbereich Biologie/Chemie, AG Genetik, Barbarastr. 11, 49076 Osnabrück, Germany
| | - Sabrina Koch
- Universität Osnabrück, Fachbereich Biologie/Chemie, AG Genetik, Barbarastr. 11, 49076 Osnabrück, Germany
| | - Hans-Peter Schmitz
- Universität Osnabrück, Fachbereich Biologie/Chemie, AG Genetik, Barbarastr. 11, 49076 Osnabrück, Germany
| | - Jürgen J Heinisch
- Universität Osnabrück, Fachbereich Biologie/Chemie, AG Genetik, Barbarastr. 11, 49076 Osnabrück, Germany
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Current awareness on yeast. Yeast 2006. [DOI: 10.1002/yea.1317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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Abstract
In this review, we discuss new insights in cell wall architecture and cell wall construction in the ascomycetous yeast Saccharomyces cerevisiae. Transcriptional profiling studies combined with biochemical work have provided ample evidence that the cell wall is a highly adaptable organelle. In particular, the protein population that is anchored to the stress-bearing polysaccharides of the cell wall, and forms the interface with the outside world, is highly diverse. This diversity is believed to play an important role in adaptation of the cell to environmental conditions, in growth mode and in survival. Cell wall construction is tightly controlled and strictly coordinated with progression of the cell cycle. This is reflected in the usage of specific cell wall proteins during consecutive phases of the cell cycle and in the recent discovery of a cell wall integrity checkpoint. When the cell is challenged with stress conditions that affect the cell wall, a specific transcriptional response is observed that includes the general stress response, the cell wall integrity pathway and the calcineurin pathway. This salvage mechanism includes increased expression of putative cell wall assemblases and some potential cross-linking cell wall proteins, and crucial changes in cell wall architecture. We discuss some more enzymes involved in cell wall construction and also potential inhibitors of these enzymes. Finally, we use both biochemical and genomic data to infer that the architectural principles used by S. cerevisiae to build its cell wall are also used by many other ascomycetous yeasts and also by some mycelial ascomycetous fungi.
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Affiliation(s)
- Frans M Klis
- Swammerdam Institute for Life Sciences, University of Amsterdam, BioCentrum Amsterdam, The Netherlands.
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