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Brown JC, Ballou ER. Is Cryptococcus neoformans a pleomorphic fungus? Curr Opin Microbiol 2024; 82:102539. [PMID: 39260180 DOI: 10.1016/j.mib.2024.102539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 05/22/2024] [Accepted: 08/19/2024] [Indexed: 09/13/2024]
Abstract
Improved understanding of the human fungal pathogen Cryptococcus neoformans, classically described as a basidiomycete budding yeast, has revealed new infection-relevant single cell morphologies in vivo and in vitro. Here, we ask whether these morphologies constitute true morphotypes, requiring updated classification of C. neoformans as a pleomorphic fungus. We profile recent discoveries of C. neoformans seed cells and titan cells and provide a framework for determining whether these and other recently described single-cell morphologies constitute true morphotypes. We demonstrate that multiple C. neoformans single-cell morphologies are transcriptionally distinct, stable, heritable, and associated with active growth and therefore should be considered true morphotypes in line with the classification in other well-studied fungi. We conclude that C. neoformans is a pleomorphic fungus with an important capacity for morphotype switching that underpins pathogenesis.
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Affiliation(s)
- Jessica Cs Brown
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA.
| | - Elizabeth R Ballou
- Medical Research Council Centre for Medical Mycology at the University of Exeter, Exeter EX4 4QD, UK.
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2
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Santos RS, Martins-Silva G, Padilla AAÁ, Possari M, Degello SD, Bernardes Brustolini OJ, Vasconcelos ATR, Vallim MA, Pascon RC. Transcriptional and Post-Translational Roles of Calcineurin in Cationic Stress and Glycerol Biosynthesis in Cryptococcus neoformans. J Fungi (Basel) 2024; 10:531. [PMID: 39194857 DOI: 10.3390/jof10080531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2024] [Revised: 07/14/2024] [Accepted: 07/19/2024] [Indexed: 08/29/2024] Open
Abstract
Stress management is an adaptive advantage for survival in adverse environments. Pathogens face this challenge during host colonization, requiring an appropriate stress response to establish infection. The fungal pathogen Cryptococcus neoformans undergoes thermal, oxidative, and osmotic stresses in the environment and animal host. Signaling systems controlled by Ras1, Hog1, and calcineurin respond to high temperatures and osmotic stress. Cationic stress caused by Na+, K+, and Li+ can be overcome with glycerol, the preferred osmolyte. Deleting the glycerol phosphate phosphatase gene (GPP2) prevents cells from accumulating glycerol due to a block in the last step of its biosynthetic pathway. Gpp2 accumulates in a phosphorylated form in a cna1Δ strain, and a physical interaction between Gpp2 and Cna1 was found; moreover, the gpp2Δ strain undergoes slow growth and has attenuated virulence in animal models of infection. We provide biochemical evidence that growth in 1 M NaCl increases glycerol content in the wild type, whereas gpp2Δ, cna1Δ, and cnb1Δ mutants fail to accumulate it. The deletion of cnb1Δ or cna1Δ renders yeast cells sensitive to cationic stress, and the Gfp-Gpp2 protein assumes an abnormal localization. We suggest a mechanism in which calcineurin controls Gpp2 at the post-translational level, affecting its localization and activity, leading to glycerol biosynthesis. Also, we showed the transcriptional profile of glycerol-deficient mutants and established the cationic stress response mediated by calcineurin; among the biological processes differentially expressed are carbon utilization, translation, transmembrane transport, glutathione metabolism, oxidative stress response, and transcription regulation. To our knowledge, this is the first time that this transcriptional profile has been described. These results have implications for pathogen stress adaptability.
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Affiliation(s)
- Ronaldo Silva Santos
- Universidade Federal de São Paulo, Campus Diadema, Rua São Nicolau, 210, Diadema 09913-030, SP, Brazil
| | - Gabriel Martins-Silva
- Universidade Federal de São Paulo, Campus Diadema, Rua São Nicolau, 210, Diadema 09913-030, SP, Brazil
| | | | - Mateus Possari
- Universidade Federal de São Paulo, Campus Diadema, Rua São Nicolau, 210, Diadema 09913-030, SP, Brazil
| | | | - Otávio J Bernardes Brustolini
- Laboratório Nacional de Computação Científica-LNCC, Labinfo-Laboratório de Bioinformática, Petrópolis 25651-075, RJ, Brazil
| | - Ana Tereza Ribeiro Vasconcelos
- Laboratório Nacional de Computação Científica-LNCC, Labinfo-Laboratório de Bioinformática, Petrópolis 25651-075, RJ, Brazil
| | - Marcelo Afonso Vallim
- Universidade Federal de São Paulo, Campus Diadema, Rua São Nicolau, 210, Diadema 09913-030, SP, Brazil
| | - Renata C Pascon
- Universidade Federal de São Paulo, Campus Diadema, Rua São Nicolau, 210, Diadema 09913-030, SP, Brazil
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Ayhan DH, Abbondante S, Martínez-Soto D, Milo S, Rickelton K, Sohrab V, Kotera S, Arie T, Marshall ME, Rocha MC, Haridas S, Grigoriev IV, Shlezinger N, Pearlman E, Ma LJ. The differential virulence of Fusarium strains causing corneal infections and plant diseases is associated with accessory chromosome composition. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.23.595639. [PMID: 38826335 PMCID: PMC11142239 DOI: 10.1101/2024.05.23.595639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2024]
Abstract
Fusarium oxysporum is a cross-kingdom pathogen. While some strains cause disseminated fusariosis and blinding corneal infections in humans, others are responsible for devastating vascular wilt diseases in plants. To better understand the distinct adaptations of F. oxysporum to animal or plant hosts, we conducted a comparative phenotypic and genetic analysis of two strains: MRL8996 (isolated from a keratitis patient) and Fol4287 (isolated from a wilted tomato [Solanum lycopersicum]). In vivo infection of mouse corneas and tomato plants revealed that, while both strains cause symptoms in both hosts, MRL8996 caused more severe corneal ulceration and perforation in mice, whereas Fol4287 induced more pronounced wilting symptoms in tomato. In vitro assays using abiotic stress treatments revealed that the human pathogen MRL8996 was better adapted to elevated temperatures, whereas the plant pathogen Fol4287 was more tolerant of osmotic and cell wall stresses. Both strains displayed broad resistance to antifungal treatment, with MRL8996 exhibiting the paradoxical effect of increased tolerance to higher concentrations of the antifungal caspofungin. We identified a set of accessory chromosomes (ACs) and protein-encoding genes with distinct transposon profiles and functions, respectively, between MRL8996 and Fol4287. Interestingly, ACs from both genomes also encode proteins with shared functions, such as chromatin remodeling and post-translational protein modifications. Our phenotypic assays and comparative genomics analyses lay the foundation for future studies correlating genotype with phenotype and for developing targeted antifungals for agricultural and clinical uses.
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Affiliation(s)
- Dilay Hazal Ayhan
- Biochemistry and Molecular Biology, University of Massachusetts Amherst, Amherst, MA, USA
- Molecular and Cellular Biology, University of Massachusetts Amherst, Amherst, MA, USA
| | - Serena Abbondante
- Physiology and Biophysics and Ophthalmology, University of California, Irvine, USA University of Massachusetts Amherst, Amherst, MA, USA
| | - Domingo Martínez-Soto
- Department of Microbiology, Centro de Investigación Científica y Educación Superior de Ensenada (CICESE), Ensenada, Baja California, Mexico
| | - Shira Milo
- Biochemistry and Molecular Biology, University of Massachusetts Amherst, Amherst, MA, USA
| | - Katherine Rickelton
- Biochemistry and Molecular Biology, University of Massachusetts Amherst, Amherst, MA, USA
- Molecular and Cellular Biology, University of Massachusetts Amherst, Amherst, MA, USA
| | - Vista Sohrab
- Biochemistry and Molecular Biology, University of Massachusetts Amherst, Amherst, MA, USA
| | - Shunsuke Kotera
- Laboratory of Plant Pathology, Graduate School of Agriculture, Tokyo University of Agriculture and Technology (TUAT), Fuchu, Tokyo, Japan
| | - Tsutomu Arie
- Laboratory of Plant Pathology, Graduate School of Agriculture, Tokyo University of Agriculture and Technology (TUAT), Fuchu, Tokyo, Japan
| | - Michaela Ellen Marshall
- Physiology and Biophysics and Ophthalmology, University of California, Irvine, USA University of Massachusetts Amherst, Amherst, MA, USA
| | - Marina Campos Rocha
- The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Sajeet Haridas
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Igor V. Grigoriev
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Neta Shlezinger
- The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Eric Pearlman
- Physiology and Biophysics and Ophthalmology, University of California, Irvine, USA University of Massachusetts Amherst, Amherst, MA, USA
| | - Li-Jun Ma
- Biochemistry and Molecular Biology, University of Massachusetts Amherst, Amherst, MA, USA
- Molecular and Cellular Biology, University of Massachusetts Amherst, Amherst, MA, USA
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4
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Martins-Santana L, Petrucelli MF, Sanches PR, Almeida F, Martinez-Rossi NM, Rossi A. The StuA Transcription Factor and Alternative Splicing Mechanisms Drive the Levels of MAPK Hog1 Transcripts in the Dermatophyte Trichophyton rubrum. Mycopathologia 2024; 189:37. [PMID: 38704808 DOI: 10.1007/s11046-024-00842-5] [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: 10/15/2023] [Accepted: 03/13/2024] [Indexed: 05/07/2024]
Abstract
Trichophyton rubrum is a human fungal pathogen that causes dermatophytosis, an infection that affects keratinized tissues. Integrated molecular signals coordinate mechanisms that control pathogenicity. Transcriptional regulation is a core regulation of relevant fungal processes. Previous RNA sequencing data revealed that the absence of the transcription factor StuA resulted in the differential expression of the MAPK-related high glycerol osmolarity gene (hog1) in T. rubrum. Here we validated the role of StuA in regulating the transcript levels of hog1. We showed through RT-qPCR that transcriptional regulation controls hog1 levels in response to glucose, keratin, and co-culture with human keratinocytes. In addition, we also detected hog1 pre-mRNA transcripts that underwent alternative splicing, presenting intron retention in a StuA-dependent mechanism. Our findings suggest that StuA and alternative splicing simultaneously, but not dependently, coordinate hog1 transcript levels in T. rubrum. As a means of preventing and treating dermatophytosis, our results contribute to the search for new potential drug therapies based on the molecular aspects of signaling pathways in T. rubrum.
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Affiliation(s)
- Leonardo Martins-Santana
- Department of Genetics, Ribeirão Preto Medical Schoool, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Monise Fazolin Petrucelli
- Department of Genetics, Ribeirão Preto Medical Schoool, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Pablo R Sanches
- Department of Genetics, Ribeirão Preto Medical Schoool, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Fausto Almeida
- Department of Biochemistry and Immunology, Ribeirão Preto Medical Schoool, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Nilce M Martinez-Rossi
- Department of Genetics, Ribeirão Preto Medical Schoool, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
| | - Antonio Rossi
- Department of Genetics, Ribeirão Preto Medical Schoool, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
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5
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Matsumoto Y, Sugiyama Y, Nagamachi T, Yoshikawa A, Sugita T. Hog1-mediated stress tolerance in the pathogenic fungus Trichosporon asahii. Sci Rep 2023; 13:13539. [PMID: 37598230 PMCID: PMC10439922 DOI: 10.1038/s41598-023-40825-y] [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: 06/05/2023] [Accepted: 08/17/2023] [Indexed: 08/21/2023] Open
Abstract
Trichosporon asahii is an opportunistic pathogenic fungus that causes severe and sometimes fatal infections in immunocompromised patients. Hog1, a mitogen-activated protein kinase, regulates the stress resistance of some pathogenic fungi, however its role in T. asahii has not been investigated. Here, we demonstrated that the hog1 gene-deficient T. asahii mutant is sensitive to high temperature, cell membrane stress, oxidative stress, and antifungal drugs. Growth of the hog1 gene-deficient T. asahii mutant was delayed at 40 °C. The hog1 gene-deficient T. asahii mutant also exhibited sensitivity to sodium dodecyl sulfate, hydrogen peroxide, menadione, methyl methanesulfonate, UV exposure, and antifungal drugs such as amphotericin B under a glucose-rich condition. Under a glucose-restricted condition, the hog1 gene-deficient mutant exhibited sensitivity to NaCl and KCl. The virulence of the hog1 gene-deficient mutant against silkworms was attenuated. Moreover, the viability of the hog1 gene-deficient mutant decreased in the silkworm hemolymph. These phenotypes were restored by re-introducing the hog1 gene into the gene-deficient mutant. Our findings suggest that Hog1 plays a critical role in regulating cellular stress responses in T. asahii.
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Affiliation(s)
- Yasuhiko Matsumoto
- Department of Microbiology, Meiji Pharmaceutical University, 2-522-1, Noshio, Kiyose, Tokyo, 204-8588, Japan.
| | - Yu Sugiyama
- Department of Microbiology, Meiji Pharmaceutical University, 2-522-1, Noshio, Kiyose, Tokyo, 204-8588, Japan
| | - Tae Nagamachi
- Department of Microbiology, Meiji Pharmaceutical University, 2-522-1, Noshio, Kiyose, Tokyo, 204-8588, Japan
| | - Asami Yoshikawa
- Department of Microbiology, Meiji Pharmaceutical University, 2-522-1, Noshio, Kiyose, Tokyo, 204-8588, Japan
| | - Takashi Sugita
- Department of Microbiology, Meiji Pharmaceutical University, 2-522-1, Noshio, Kiyose, Tokyo, 204-8588, Japan
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Zhang L, Li Y, Dong L, Sun K, Liu H, Ma Z, Yan L, Yin Y. MAP Kinase FgHog1 and Importin β FgNmd5 Regulate Calcium Homeostasis in Fusarium graminearum. J Fungi (Basel) 2023; 9:707. [PMID: 37504696 PMCID: PMC10381525 DOI: 10.3390/jof9070707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 06/16/2023] [Accepted: 06/23/2023] [Indexed: 07/29/2023] Open
Abstract
Maintaining cellular calcium (Ca2+) homeostasis is essential for many aspects of cellular life. The high-osmolarity glycerol (HOG) mitogen-activated protein kinase (MAPK) pathway responsible for signal integration and transduction plays crucial roles in environmental adaptation, especially in the response to osmotic stress. Hog1 is activated by transient Ca2+ increase in yeast, but the functions of the HOG pathway in Ca2+ homeostasis are largely unknown. We found that the HOG pathway was involved in the regulation of Ca2+ homeostasis in Fusarium graminearum, a devastating fungal pathogen of cereal crops. The deletion mutants of HOG pathway displayed increased sensitivity to Ca2+ and FK506, and elevated intracellular Ca2+ content. Ca2+ treatment induced the phosphorylation of FgHog1, and the phosphorylated FgHog1 was transported into the nucleus by importin β FgNmd5. Moreover, the increased phosphorylation and nuclear accumulation of FgHog1 upon Ca2+ treatment is independent of the calcineurin pathway that is conserved and downstream of the Ca2+ signal. Taken together, this study reported the novel function of FgHog1 in the regulation of Ca2+ homeostasis in F. graminearum, which advance the understanding of the HOG pathway and the association between the HOG and calcineurin pathways in fungi.
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Affiliation(s)
- Lixin Zhang
- Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China
| | - Yiqing Li
- Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China
| | - Lanlan Dong
- Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China
| | - Kewei Sun
- Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China
| | - Hao Liu
- Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China
| | - Zhonghua Ma
- Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China
| | - Leiyan Yan
- Ningbo Academy of Agricultural Sciences, Ningbo 315040, China
| | - Yanni Yin
- Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China
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7
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Ye PL, Yuan B, Wang XQ, Zhang MM, Zhao XQ. Modification of Phosphorylation Sites in the Yeast Lysine Methyltransferase Set5 Exerts Influences on the Mitogen-Activated Protein Kinase Hog1 under Prolonged Acetic Acid Stress. Microbiol Spectr 2023; 11:e0301122. [PMID: 36975803 PMCID: PMC10100857 DOI: 10.1128/spectrum.03011-22] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Accepted: 02/27/2023] [Indexed: 03/29/2023] Open
Abstract
Responses to acetic acid toxicity in the budding yeast Saccharomyces cerevisiae have widespread implications in the biorefinery of lignocellulosic biomass and food preservation. Our previous studies revealed that Set5, the yeast lysine methyltransferase and histone H4 methyltransferase, was involved in acetic acid stress tolerance. However, it is still mysterious how Set5 functions and interacts with the known stress signaling network. Here, we revealed that elevated phosphorylation of Set5 during acetic acid stress is accompanied by enhanced expression of the mitogen-activated protein kinase (MAPK) Hog1. Further experiments uncovered that the phosphomimetic mutation of Set5 endowed yeast cells with improved growth and fermentation performance and altered transcription of specific stress-responsive genes. Intriguingly, Set5 was found to bind the coding region of HOG1 and regulate its transcription, along with increased expression and phosphorylation of Hog1. A protein-protein interaction between Set5 and Hog1 was also revealed. In addition, modification of Set5 phosphosites was shown to regulate reactive oxygen species (ROS) accumulation, which is known to affect yeast acetic acid stress tolerance. The findings in this study imply that Set5 may function together with the central kinase Hog1 to coordinate cell growth and metabolism in response to stress. IMPORTANCE Hog1 is the yeast homolog of p38 MAPK in mammals that is conserved across eukaryotes, and it plays crucial roles in stress tolerance, fungal pathogenesis, and disease treatments. Here, we provide evidence that modification of Set5 phosphorylation sites regulates the expression and phosphorylation of Hog1, which expands current knowledge on upstream regulation of the Hog1 stress signaling network. Set5 and its homologous proteins are present in humans and various eukaryotes. The newly identified effects of Set5 phosphorylation site modifications in this study benefit an in-depth understanding of eukaryotic stress signaling, as well as the treatment of human diseases.
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Affiliation(s)
- Pei-Liang Ye
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Bing Yuan
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Xue-Qing Wang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Ming-Ming Zhang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Xin-Qing Zhao
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
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Scott J, Valero C, Mato-López Á, Donaldson IJ, Roldán A, Chown H, Van Rhijn N, Lobo-Vega R, Gago S, Furukawa T, Morogovsky A, Ben Ami R, Bowyer P, Osherov N, Fontaine T, Goldman GH, Mellado E, Bromley M, Amich J. Aspergillus fumigatus Can Display Persistence to the Fungicidal Drug Voriconazole. Microbiol Spectr 2023; 11:e0477022. [PMID: 36912663 PMCID: PMC10100717 DOI: 10.1128/spectrum.04770-22] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 02/12/2023] [Indexed: 03/14/2023] Open
Abstract
Aspergillus fumigatus is a filamentous fungus that can infect the lungs of patients with immunosuppression and/or underlying lung diseases. The mortality associated with chronic and invasive aspergillosis infections remain very high, despite availability of antifungal treatments. In the last decade, there has been a worrisome emergence and spread of resistance to the first-line antifungals, the azoles. The mortality caused by resistant isolates is even higher, and patient management is complicated as the therapeutic options are reduced. Nevertheless, treatment failure is also common in patients infected with azole-susceptible isolates, which can be due to several non-mutually exclusive reasons, such as poor drug absorption. In addition, the phenomena of tolerance or persistence, where susceptible pathogens can survive the action of an antimicrobial for extended periods, have been associated with treatment failure in bacterial infections, and their occurrence in fungal infections already proposed. Here, we demonstrate that some isolates of A. fumigatus display persistence to voriconazole. A subpopulation of the persister isolates can survive for extended periods and even grow at low rates in the presence of supra-MIC of voriconazole and seemingly other azoles. Persistence cannot be eradicated with adjuvant drugs or antifungal combinations and seemed to reduce the efficacy of treatment for certain individuals in a Galleria mellonella model of infection. Furthermore, persistence implies a distinct transcriptional profile, demonstrating that it is an active response. We propose that azole persistence might be a relevant and underestimated factor that could influence the outcome of infection in human aspergillosis. IMPORTANCE The phenomena of antibacterial tolerance and persistence, where pathogenic microbes can survive for extended periods in the presence of cidal drug concentrations, have received significant attention in the last decade. Several mechanisms of action have been elucidated, and their relevance for treatment failure in bacterial infections demonstrated. In contrast, our knowledge of antifungal tolerance and, in particular, persistence is still very limited. In this study, we have characterized the response of the prominent fungal pathogen Aspergillus fumigatus to the first-line therapy antifungal voriconazole. We comprehensively show that some isolates display persistence to this fungicidal antifungal and propose various potential mechanisms of action. In addition, using an alternative model of infection, we provide initial evidence to suggest that persistence may cause treatment failure in some individuals. Therefore, we propose that azole persistence is an important factor to consider and further investigate in A. fumigatus.
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Affiliation(s)
- Jennifer Scott
- Manchester Fungal Infection Group, Division of Evolution, Infection, and Genomics, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Clara Valero
- Manchester Fungal Infection Group, Division of Evolution, Infection, and Genomics, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Álvaro Mato-López
- Mycology Reference Laboratory (Laboratorio de Referencia e Investigación en Micología [LRIM]), National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), Majadahonda, Madrid, Spain
| | - Ian J. Donaldson
- Bioinformatics Core Facility, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Alejandra Roldán
- Mycology Reference Laboratory (Laboratorio de Referencia e Investigación en Micología [LRIM]), National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), Majadahonda, Madrid, Spain
| | - Harry Chown
- Manchester Fungal Infection Group, Division of Evolution, Infection, and Genomics, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Norman Van Rhijn
- Manchester Fungal Infection Group, Division of Evolution, Infection, and Genomics, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Rebeca Lobo-Vega
- Mycology Reference Laboratory (Laboratorio de Referencia e Investigación en Micología [LRIM]), National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), Majadahonda, Madrid, Spain
| | - Sara Gago
- Manchester Fungal Infection Group, Division of Evolution, Infection, and Genomics, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Takanori Furukawa
- Manchester Fungal Infection Group, Division of Evolution, Infection, and Genomics, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Alma Morogovsky
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine Ramat-Aviv, Tel-Aviv, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ronen Ben Ami
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine Ramat-Aviv, Tel-Aviv, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Paul Bowyer
- Manchester Fungal Infection Group, Division of Evolution, Infection, and Genomics, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Nir Osherov
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine Ramat-Aviv, Tel-Aviv, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Thierry Fontaine
- Institut Pasteur, Université de Paris, INRAE, USC2019, Unité Biologie et Pathogénicité Fongiques, Paris, France
| | - Gustavo H. Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Emilia Mellado
- Mycology Reference Laboratory (Laboratorio de Referencia e Investigación en Micología [LRIM]), National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), Majadahonda, Madrid, Spain
- CiberInfec ISCIII, CIBER en Enfermedades Infecciosas, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| | - Michael Bromley
- Manchester Fungal Infection Group, Division of Evolution, Infection, and Genomics, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Jorge Amich
- Manchester Fungal Infection Group, Division of Evolution, Infection, and Genomics, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- Mycology Reference Laboratory (Laboratorio de Referencia e Investigación en Micología [LRIM]), National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), Majadahonda, Madrid, Spain
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9
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Nicoletti G, White K. The Anti-Fungal Activity of Nitropropenyl Benzodioxole (NPBD), a Redox-Thiol Oxidant and Tyrosine Phosphatase Inhibitor. Antibiotics (Basel) 2022; 11:antibiotics11091188. [PMID: 36139967 PMCID: PMC9495065 DOI: 10.3390/antibiotics11091188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 08/28/2022] [Accepted: 08/30/2022] [Indexed: 11/16/2022] Open
Abstract
Phylogenetically diverse fungal species are an increasing cause of severe disease and mortality. Identification of new targets and development of new fungicidal drugs are required to augment the effectiveness of current chemotherapy and counter increasing resistance in pathogens. Nitroalkenyl benzene derivatives are thiol oxidants and inhibitors of cysteine-based molecules, which show broad biological activity against microorganisms. Nitropropenyl benzodioxole (NPBD), one of the most active antimicrobial derivatives, shows high activity in MIC assays for phylogenetically diverse saprophytic, commensal and parasitic fungi. NPBD was fungicidal to all species except the dermatophytic fungi, with an activity profile comparable to that of Amphotericin B and Miconazole. NPBD showed differing patterns of dynamic kill rates under different growth conditions for Candida albicans and Aspergillus fumigatus and was rapidly fungicidal for non-replicating vegetative forms and microconidia. It did not induce resistant or drug tolerant strains in major pathogens on long term exposure. A literature review highlights the complexity and interactivity of fungal tyrosine phosphate and redox signaling pathways, their differing metabolic effects in fungal species and identifies some targets for inhibition. A comparison of the metabolic activities of Amphotericin B, Miconazole and NPBD highlights the multiple cellular functions of these agents and the complementarity of many mechanisms. The activity profile of NPBD illustrates the functional diversity of fungal tyrosine phosphatases and thiol-based redox active molecules and contributes to the validation of tyrosine phosphatases and redox thiol molecules as related and complementary selective targets for antimicrobial drug development. NPBD is a selective antifungal agent with low oral toxicity which would be suitable for local treatment of skin and mucosal infections.
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10
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Chen L, Li E, Wu W, Wang G, Zhang J, Guo X, Xing F. The Secondary Metabolites and Biosynthetic Diversity From Aspergillus ochraceus. Front Chem 2022; 10:938626. [PMID: 36092677 PMCID: PMC9452667 DOI: 10.3389/fchem.2022.938626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Accepted: 06/21/2022] [Indexed: 12/04/2022] Open
Abstract
Aspergillus ochraceus, generally known as a food spoilage fungus, is the representative species in Aspergillus section Circumdati. A. ochraceus strains are widely distributed in nature, and usually isolated from cereal, coffee, fruit, and beverage. Increasing cases suggest A. ochraceus acts as human and animal pathogens due to producing the mycotoxins. However, in terms of benefits to mankind, A. ochraceus is the potential source of industrial enzymes, and has excellent capability to produce diverse structural products, including polyketides, nonribosomal peptides, diketopiperazine alkaloids, benzodiazepine alkaloids, pyrazines, bis-indolyl benzenoids, nitrobenzoyl sesquiterpenoids, and steroids. This review outlines recent discovery, chemical structure, biosynthetic pathway, and bio-activity of the natural compounds from A. ochraceus.
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Affiliation(s)
- Lin Chen
- Comprehensive Utilization of Edible and Medicinal Plant Resources Engineering Technology Research Center, Zhengzhou Key Laboratory of Synthetic Biology of Natural Products, Zhengzhou Key Laboratory of Medicinal Resources Research, Huanghe Science and Technology College, Zhengzhou, China
| | - Erfeng Li
- Horticulture and Landscape College, Tianjin Agricultural University, Tianjin, China
| | - Wenqing Wu
- Horticulture and Landscape College, Tianjin Agricultural University, Tianjin, China
| | - Gang Wang
- Comprehensive Utilization of Edible and Medicinal Plant Resources Engineering Technology Research Center, Zhengzhou Key Laboratory of Synthetic Biology of Natural Products, Zhengzhou Key Laboratory of Medicinal Resources Research, Huanghe Science and Technology College, Zhengzhou, China
- Key Laboratory of Agro-Products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Jiaqian Zhang
- Horticulture and Landscape College, Tianjin Agricultural University, Tianjin, China
| | - Xu Guo
- Horticulture and Landscape College, Tianjin Agricultural University, Tianjin, China
| | - Fuguo Xing
- Key Laboratory of Agro-Products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, China
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11
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Celińska E. "Fight-flight-or-freeze" - how Yarrowia lipolytica responds to stress at molecular level? Appl Microbiol Biotechnol 2022; 106:3369-3395. [PMID: 35488934 PMCID: PMC9151528 DOI: 10.1007/s00253-022-11934-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 04/14/2022] [Accepted: 04/20/2022] [Indexed: 11/10/2022]
Abstract
Abstract
Yarrowia lipolytica is a popular yeast species employed in multiple biotechnological production processes. High resistance to extreme environmental conditions or metabolic burden triggered by synthetically forced over-synthesis of a target metabolite has its practical consequences. The proud status of an “industrial workhorse” that Y. lipolytica has gained is directly related to such a quality of this species. With the increasing amount of knowledge coming from detailed functional studies and comprehensive omics analyses, it is now possible to start painting the landscape of the molecular background behind stress response and adaptation in Y. lipolytica. This review summarizes the current state-of-art of a global effort in revealing how Y. lipolytica responds to both environmental threats and the intrinsic burden caused by the overproduction of recombinant secretory proteins at the molecular level. Detailed lists of genes, proteins, molecules, and biological processes deregulated upon exposure to external stress factors or affected by over-synthesis of heterologous proteins are provided. Specificities and universalities of Y. lipolytica cellular response to different extrinsic and intrinsic threats are highlighted. Key points • Y. lipolytica as an industrial workhorse is subjected to multiple stress factors. • Cellular responses together with involved genes, proteins, and molecules are reviewed. • Native stress response mechanisms are studied and inspire engineering strategies.
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Affiliation(s)
- Ewelina Celińska
- Department of Biotechnology and Food Microbiology, Poznan University of Life Sciences, Wojska Polskiego 48, 60-627, Poznan, Poland.
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12
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WMR Peptide as Antifungal and Antibiofilm against Albicans and Non-Albicans Candida Species: Shreds of Evidence on the Mechanism of Action. Int J Mol Sci 2022; 23:ijms23042151. [PMID: 35216270 PMCID: PMC8879636 DOI: 10.3390/ijms23042151] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 02/07/2022] [Accepted: 02/14/2022] [Indexed: 02/06/2023] Open
Abstract
Candida species are the most common fungal pathogens infecting humans and can cause severe illnesses in immunocompromised individuals. The increased resistance of Candida to traditional antifungal drugs represents a great challenge in clinical settings. Therefore, novel approaches to overcome antifungal resistance are desired. Here, we investigated the use of an antimicrobial peptide WMR against Candida albicans and non-albicans Candida species in vitro and in vivo. Results showed a WMR antifungal activity on all Candida planktonic cells at concentrations between 25 μM to >50 μM and exhibited activity at sub-MIC concentrations to inhibit biofilm formation and eradicate mature biofilm. Furthermore, in vitro antifungal effects of WMR were confirmed in vivo as demonstrated by a prolonged survival rate of larvae infected by Candida species when the peptide was administered before or after infection. Additional experiments to unravel the antifungal mechanism were performed on C. albicans and C. parapsilosis. The time-killing curves showed their antifungal activity, which was further confirmed by the induced intracellular and mitochondrial reactive oxygen species accumulation; WMR significantly suppressed drug efflux, down-regulating the drug transporter encoding genes CDR1. Moreover, the ability of WMR to penetrate within the cells was demonstrated by confocal laser scanning microscopy. These findings provide novel insights for the antifungal mechanism of WMR against Candida albicans and non-albicans, providing fascinating scenarios for the identification of new potential antifungal targets.
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13
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Yaakoub H, Sanchez NS, Ongay-Larios L, Courdavault V, Calenda A, Bouchara JP, Coria R, Papon N. The high osmolarity glycerol (HOG) pathway in fungi †. Crit Rev Microbiol 2021; 48:657-695. [PMID: 34893006 DOI: 10.1080/1040841x.2021.2011834] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
While fungi are widely occupying nature, many species are responsible for devastating mycosis in humans. Such niche diversity explains how quick fungal adaptation is necessary to endow the capacity of withstanding fluctuating environments and to cope with host-imposed conditions. Among all the molecular mechanisms evolved by fungi, the most studied one is the activation of the phosphorelay signalling pathways, of which the high osmolarity glycerol (HOG) pathway constitutes one of the key molecular apparatus underpinning fungal adaptation and virulence. In this review, we summarize the seminal knowledge of the HOG pathway with its more recent developments. We specifically described the HOG-mediated stress adaptation, with a particular focus on osmotic and oxidative stress, and point out some lags in our understanding of its involvement in the virulence of pathogenic species including, the medically important fungi Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus, compared to the model yeast Saccharomyces cerevisiae. Finally, we also highlighted some possible applications of the HOG pathway modifications to improve the fungal-based production of natural products in the industry.
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Affiliation(s)
- Hajar Yaakoub
- Univ Angers, Univ Brest, GEIHP, SFR ICAT, Angers, France
| | - Norma Silvia Sanchez
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City, Mexico
| | - Laura Ongay-Larios
- Unidad de Biología Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Vincent Courdavault
- EA2106 "Biomolécules et Biotechnologies Végétales", Université de Tours, Tours, France
| | | | | | - Roberto Coria
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City, Mexico
| | - Nicolas Papon
- Univ Angers, Univ Brest, GEIHP, SFR ICAT, Angers, France
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14
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A. L. Bataineh MT, Soares NC, Semreen MH, Cacciatore S, Dash NR, Hamad M, Mousa MK, Salam JSA, Al Gharaibeh MF, Zerbini LF, Hamad M. Candida albicans PPG1, a serine/threonine phosphatase, plays a vital role in central carbon metabolisms under filament-inducing conditions: A multi-omics approach. PLoS One 2021; 16:e0259588. [PMID: 34874940 PMCID: PMC8651141 DOI: 10.1371/journal.pone.0259588] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 10/21/2021] [Indexed: 01/01/2023] Open
Abstract
Candida albicans is the leading cause of life-threatening bloodstream candidiasis, especially among immunocompromised patients. The reversible morphological transition from yeast to hyphal filaments in response to host environmental cues facilitates C. albicans tissue invasion, immune evasion, and dissemination. Hence, it is widely considered that filamentation represents one of the major virulence properties in C. albicans. We have previously characterized Ppg1, a PP2A-type protein phosphatase that controls filament extension and virulence in C. albicans. This study conducted RNA sequencing analysis of samples obtained from C. albicans wild type and ppg1Δ/Δ strains grown under filament-inducing conditions. Overall, ppg1Δ/Δ strain showed 1448 upregulated and 710 downregulated genes, representing approximately one-third of the entire annotated C. albicans genome. Transcriptomic analysis identified significant downregulation of well-characterized genes linked to filamentation and virulence, such as ALS3, HWP1, ECE1, and RBT1. Expression analysis showed that essential genes involved in C. albicans central carbon metabolisms, including GDH3, GPD1, GPD2, RHR2, INO1, AAH1, and MET14 were among the top upregulated genes. Subsequent metabolomics analysis of C. albicans ppg1Δ/Δ strain revealed a negative enrichment of metabolites with carboxylic acid substituents and a positive enrichment of metabolites with pyranose substituents. Altogether, Ppg1 in vitro analysis revealed a link between metabolites substituents and filament formation controlled by a phosphatase to regulate morphogenesis and virulence.
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Affiliation(s)
- Mohammad Tahseen A. L. Bataineh
- College of Medicine, University of Sharjah, Sharjah, UAE
- Research Institute for Medical & Health Sciences at University of Sharjah, Sharjah, UAE
- Center for Biotechnology, Khalifa University of Science and Technology, Abu Dhabi, UAE
- Department of Genetics and Molecular Biology, College Of Medicine And Health Sciences, Khalifa University of Science and Technology, Abu Dhabi, UAE
| | - Nelson Cruz Soares
- Research Institute for Medical & Health Sciences at University of Sharjah, Sharjah, UAE
- Department of Medicinal Chemistry, College of Pharmacy, University of Sharjah, Sharjah, UAE
| | - Mohammad Harb Semreen
- Research Institute for Medical & Health Sciences at University of Sharjah, Sharjah, UAE
- Department of Medicinal Chemistry, College of Pharmacy, University of Sharjah, Sharjah, UAE
| | - Stefano Cacciatore
- Cancer Genomics Group, International Centre for Genetic Engineering and Biotechnology, Cape Town, South Africa
- Institute for Reproductive and Developmental Biology, Imperial College, London, United Kingdom
| | | | - Mohamad Hamad
- Research Institute for Medical & Health Sciences at University of Sharjah, Sharjah, UAE
- Department of Medical Laboratory Sciences, College of Health Sciences, University of Sharjah, Sharjah, UAE
| | - Muath Khairi Mousa
- Department of Medicinal Chemistry, College of Pharmacy, University of Sharjah, Sharjah, UAE
| | | | | | - Luiz F. Zerbini
- Cancer Genomics Group, International Centre for Genetic Engineering and Biotechnology, Cape Town, South Africa
| | - Mawieh Hamad
- Research Institute for Medical & Health Sciences at University of Sharjah, Sharjah, UAE
- Department of Medical Laboratory Sciences, College of Health Sciences, University of Sharjah, Sharjah, UAE
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15
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Liao B, Ye X, Chen X, Zhou Y, Cheng L, Zhou X, Ren B. The two-component signal transduction system and its regulation in Candida albicans. Virulence 2021; 12:1884-1899. [PMID: 34233595 PMCID: PMC8274445 DOI: 10.1080/21505594.2021.1949883] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 06/13/2021] [Accepted: 06/18/2021] [Indexed: 02/08/2023] Open
Abstract
Candida albicans, which can cause superficial and life-threatening systemic infections, is the most common opportunistic fungal pathogen in the human microbiome. The two-component system is one of the most important C. albicans signal transduction pathways, regulating the response to oxidative and osmotic stresses, adhesion, morphogenesis, cell wall synthesis, virulence, drug resistance, and the host-pathogen interactions. Notably, some components of this signaling pathway have not been found in the human genome, indicating that the two-component system of C. albicans can be a potential target for new antifungal agents. Here, we summarize the composition, signal transduction, and regulation of the two-component system of C. albicans to emphasize its essential roles in the pathogenesis of C. albicans and the new therapeutic target for antifungal drugs.
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Affiliation(s)
- Biaoyou Liao
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases& West China School of Stomatology, Sichuan University, Chengdu, China
| | - Xingchen Ye
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases& West China School of Stomatology, Sichuan University, Chengdu, China
| | - Xi Chen
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases& West China School of Stomatology, Sichuan University, Chengdu, China
- Department of Operative Dentistry and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Yujie Zhou
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases& West China School of Stomatology, Sichuan University, Chengdu, China
- Department of Operative Dentistry and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Lei Cheng
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases& West China School of Stomatology, Sichuan University, Chengdu, China
- Department of Operative Dentistry and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Xuedong Zhou
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases& West China School of Stomatology, Sichuan University, Chengdu, China
- Department of Operative Dentistry and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Biao Ren
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases& West China School of Stomatology, Sichuan University, Chengdu, China
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16
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Schruefer S, Spadinger A, Kleinemeier C, Schmid L, Ebel F. Ypd1 Is an Essential Protein of the Major Fungal Pathogen Aspergillus fumigatus and a Key Element in the Phosphorelay That Is Targeted by the Antifungal Drug Fludioxonil. FRONTIERS IN FUNGAL BIOLOGY 2021; 2:756990. [PMID: 37744118 PMCID: PMC10512271 DOI: 10.3389/ffunb.2021.756990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 09/20/2021] [Indexed: 09/26/2023]
Abstract
Aspergillus fumigatus is a major fungal pathogen causing life threatening infections in immunocompromised humans and certain animals. The HOG pathway is for two reasons interesting in this context: firstly, it is a stress signaling pathway that contributes to the ability of this pathogen to adapt to various stress conditions and secondly, it is the target of antifungal agents, such as fludioxonil or pyrrolnitrin. In this study, we demonstrate that Ypd1 is an essential protein in A. fumigatus. As the central component of the multistep phosphorelay it represents the functional link between the sensor histidine kinases and the downstream response regulators SskA and Skn7. A GFP-Ypd1 fusion was found to reside in both, the cytoplasm and the nucleus and this pattern was only slightly affected by fludioxonil. A strain in which the ypd1 gene is expressed from a tet-on promoter construct is unable to grow under non-inducing conditions and shows the characteristic features of A. fumigatus wild type hyphae treated with fludioxonil. Expression of wild type Ypd1 prevents this lethal phenotype, but expression of an Ypd1 mutant protein lacking the conserved histidine at position 89 was unable to do so, which confirms that A. fumigatus Ypd1 is a phosphotransfer protein. Generation of ypd1tet-on variants of several mutant strains revealed that the lethal phenotype associated with low amounts of Ypd1 depends on SskA, but not on TcsC or Skn7. The ΔsskA ypd1tet-on, but not the ΔsskAΔskn7 ypd1tet-on mutant, was sensitive to fludioxonil, which underlines the importance of Skn7 in this context. We finally succeeded to delete ypd1, but only if sskA and skn7 were both inactivated, not in a ΔsskA single mutant. Hence, a deletion of ypd1 and an inactivation of Ypd1 by fludioxonil result in similar phenotypes and the two response regulators SskA and Skn7 are involved in both processes albeit with a different relative importance.
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Affiliation(s)
| | | | | | | | - Frank Ebel
- Department of Veterinary Sciences, Institute for Infectious Diseases and Zoonoses, Chair for Bacteriology and Mycology, Ludwig-Maximilians-University, Munich, Germany
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17
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Chang CK, Kao MC, Lan CY. Antimicrobial Activity of the Peptide LfcinB15 against Candida albicans. J Fungi (Basel) 2021; 7:jof7070519. [PMID: 34209722 PMCID: PMC8306953 DOI: 10.3390/jof7070519] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/24/2021] [Accepted: 06/25/2021] [Indexed: 02/07/2023] Open
Abstract
Lactoferricin (Lfcin) is an amphipathic, cationic peptide derived from proteolytic cleavage of the N-lobe of lactoferrin (Lf). Lfcin and its derivatives possess broad-spectrum antibacterial and antifungal activities. However, unlike their antibacterial functions, the modes of action of Lfcin and its derivatives against pathogenic fungi are less well understood. In this study, the mechanisms of LfcinB15, a derivative of bovine Lfcin, against Candida albicans were, therefore, extensively investigated. LfcinB15 exhibited inhibitory activity against planktonic cells, biofilm cells, and clinical isolates of C. albicans and non-albicans Candida species. We further demonstrated that LfcinB15 is localized on the cell surface and vacuoles of C. albicans cells. Moreover, LfcinB15 uses several different methods to kill C. albicans, including disturbing the cell membrane, inducing reactive oxygen species (ROS) generation, and causing mitochondrial dysfunction. Finally, the Hog1 and Mkc1 mitogen-activated protein kinases were both activated in C. albicans cells in response to LfcinB15. These findings help us to obtain more insight into the complex mechanisms used by LfcinB15 and other Lfcin-derived peptides to fight fungal pathogens.
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Affiliation(s)
- Che-Kang Chang
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu 30013, Taiwan;
| | - Mou-Chieh Kao
- Institute of Molecular Medicine, National Tsing Hua University, Hsinchu 30013, Taiwan
- Department of Life Science, National Tsing Hua University, Hsinchu 30013, Taiwan
- Correspondence: (M.-C.K.); ; (C.-Y.L.); Tel.: +886-3-5742473 (M.-C.K.); +886-3-5742472 (C.-Y.L.)
| | - Chung-Yu Lan
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu 30013, Taiwan;
- Department of Life Science, National Tsing Hua University, Hsinchu 30013, Taiwan
- Correspondence: (M.-C.K.); ; (C.-Y.L.); Tel.: +886-3-5742473 (M.-C.K.); +886-3-5742472 (C.-Y.L.)
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18
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Bourret RB, Kennedy EN, Foster CA, Sepúlveda VE, Goldman WE. A Radical Reimagining of Fungal Two-Component Regulatory Systems. Trends Microbiol 2021; 29:883-893. [PMID: 33853736 DOI: 10.1016/j.tim.2021.03.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 03/08/2021] [Accepted: 03/09/2021] [Indexed: 11/17/2022]
Abstract
Bacterial two-component regulatory systems (TCSs) mediate signal transduction by transferring phosphoryl groups between sensor kinase and response regulator proteins, sometimes using intermediary histidine-phosphotransferase (Hpt) domains to form multistep phosphorelays. Because (i) almost all known fungal sensor kinases exhibit a domain architecture characteristic of bacterial TCS phosphorelays, (ii) all known fungal Hpts are stand-alone proteins suited to shuttle between cytoplasm and nucleus, and (iii) the best-characterized fungal TCS is a canonical phosphorelay, it is widely assumed that most or all fungal TCSs function via phosphorelays. However, fungi generally encode more sensor kinases than Hpts or response regulators, leading to a disparity between putative phosphorelay inputs and outputs. The simplest resolution of this paradox is to hypothesize that most fungal sensor kinases do not participate in phosphorelays. Reimagining how fungal TCSs might function leads to multiple testable predictions.
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Affiliation(s)
- Robert B Bourret
- Department of Microbiology & Immunology, University of North Carolina, Chapel Hill, NC 27599-7290, USA.
| | - Emily N Kennedy
- Department of Microbiology & Immunology, University of North Carolina, Chapel Hill, NC 27599-7290, USA
| | - Clay A Foster
- Department of Microbiology & Immunology, University of North Carolina, Chapel Hill, NC 27599-7290, USA
| | - Victoria E Sepúlveda
- Department of Microbiology & Immunology, University of North Carolina, Chapel Hill, NC 27599-7290, USA
| | - William E Goldman
- Department of Microbiology & Immunology, University of North Carolina, Chapel Hill, NC 27599-7290, USA
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19
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Yaakoub H, Staerck C, Mina S, Godon C, Fleury M, Bouchara JP, Calenda A. Repurposing of auranofin and honokiol as antifungals against Scedosporium species and the related fungus Lomentospora prolificans. Virulence 2021; 12:1076-1090. [PMID: 33825667 PMCID: PMC8032236 DOI: 10.1080/21505594.2021.1909266] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The slowing-down de novo drug-discovery emphasized the importance of repurposing old drugs. This is particularly true when combating infections caused by therapy-refractory microorganisms, such as Scedosporium species and Lomentospora prolificans. Recent studies on Scedosporium responses to oxidative stress underscored the importance of targeting the underlying mechanisms. Auranofin, ebselen, PX-12, honokiol, and to a lesser extent, conoidin A are known to disturb redox-homeostasis systems in many organisms. Their antifungal activity was assessed against 27 isolates belonging to the major Scedosporium species: S. apiospermum, S. aurantiacum, S. boydii, S. dehoogii, S. minutisporum, and Lomentospora prolificans. Auranofin and honokiol were the most active against all Scedosporium species (mean MIC50 values of 2.875 and 6.143 μg/ml, respectively) and against L. prolificans isolates (mean MIC50 values of 4.0 and 3.563μg/ml respectively). Combinations of auranofin with voriconazole or honokiol revealed additive effects against 9/27 and 18/27 isolates, respectively. Synergistic interaction between auranofin and honokiol was only found against one isolate of L. prolificans. The effects of auranofin upon exposure to oxidative stress were also investigated. For all species except S. dehoogii, the maximal growth in the presence of auranofin significantly decreased when adding a sublethal dose of menadione. The analysis of the expression of genes encoding oxidoreductase enzymes upon exposure of S. apiospermum to honokiol unveiled the upregulation of many genes, especially those coding peroxiredoxins, thioredoxin reductases, and glutaredoxins. Altogether, these data suggest that auranofin and honokiol act via dampening the redox balance and support their repurposing as antifungals against Scedosporium species and L. prolificans.
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Affiliation(s)
- Hajar Yaakoub
- Groupe d'Etude Des Interactions Hôte-Pathogène (GEIHP, EA 3142), SFR ICAT 4208, UNIV Angers, UNIV Brest, Institut De Biologie En Santé-IRIS, CHU Angers,Angers, France
| | - Cindy Staerck
- Groupe d'Etude Des Interactions Hôte-Pathogène (GEIHP, EA 3142), SFR ICAT 4208, UNIV Angers, UNIV Brest, Institut De Biologie En Santé-IRIS, CHU Angers,Angers, France
| | - Sara Mina
- Department of Medical Laboratory Sciences, Faculty of Health Sciences, Beirut Arab University, Beirut, Lebanon
| | - Charlotte Godon
- Groupe d'Etude Des Interactions Hôte-Pathogène (GEIHP, EA 3142), SFR ICAT 4208, UNIV Angers, UNIV Brest, Institut De Biologie En Santé-IRIS, CHU Angers,Angers, France
| | - Maxime Fleury
- Groupe d'Etude Des Interactions Hôte-Pathogène (GEIHP, EA 3142), SFR ICAT 4208, UNIV Angers, UNIV Brest, Institut De Biologie En Santé-IRIS, CHU Angers,Angers, France
| | - Jean-Philippe Bouchara
- Groupe d'Etude Des Interactions Hôte-Pathogène (GEIHP, EA 3142), SFR ICAT 4208, UNIV Angers, UNIV Brest, Institut De Biologie En Santé-IRIS, CHU Angers,Angers, France.,Département de biologie des agents infectieux , Laboratoire De Parasitologie-Mycologie, Centre Hospitalier Universitaire, Angers, France
| | - Alphonse Calenda
- Groupe d'Etude Des Interactions Hôte-Pathogène (GEIHP, EA 3142), SFR ICAT 4208, UNIV Angers, UNIV Brest, Institut De Biologie En Santé-IRIS, CHU Angers,Angers, France
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Quintana JF, Zoltner M, Field MC. Evolving Differentiation in African Trypanosomes. Trends Parasitol 2021; 37:296-303. [PMID: 33309505 DOI: 10.1016/j.pt.2020.11.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 10/15/2020] [Accepted: 11/05/2020] [Indexed: 12/12/2022]
Abstract
Differentiation is a central aspect of the parasite life cycle and encompasses adaptation to both host and environment. If we accept that evolution cannot anticipate an organism's needs as it enters a new environment, how do parasite differentiation pathways arise? The transition between vertebrate and insect stage African trypanosomes is probably one of the better studied and involves a cell-cycle arrested or 'stumpy' form that activates metabolic pathways advantageous to the parasite in the insect host. However, a range of stimuli and stress conditions can trigger similar changes, leading to formation of stumpy-like cellular states. We propose that the origin and optimisation of this differentiation program represents repurposing of a generic stress response to gain considerable gain-of-fitness associated with parasite transmission.
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Affiliation(s)
- Juan F Quintana
- Wellcome Centre for Integrative Parasitology, College of Medical, Veterinary and Life Sciences, Glasgow Biomedical Research Centre, University of Glasgow, Glasgow, UK; School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Martin Zoltner
- School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK; Biotechnology and Biomedicine Centre of the Academy of Sciences and Charles University (BIOCEV), Průmyslová 595, 252 50 Vestec, Czech Republic
| | - Mark C Field
- School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK; Institute of Parasitology, Biology Centre, Czech Academy of Sciences, 37005 Ceske Budejovice, Czech Republic.
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Silva LP, Horta MAC, Goldman GH. Genetic Interactions Between Aspergillus fumigatus Basic Leucine Zipper (bZIP) Transcription Factors AtfA, AtfB, AtfC, and AtfD. FRONTIERS IN FUNGAL BIOLOGY 2021; 2:632048. [PMID: 37744135 PMCID: PMC10512269 DOI: 10.3389/ffunb.2021.632048] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Accepted: 01/08/2021] [Indexed: 09/26/2023]
Abstract
Aspergillus fumigatus is an opportunistic fungus, capable of causing Invasive Aspergillosis in immunocompromised patients, recently transplanted or undergoing chemotherapy. In the present work, we continued the investigation on A. fumigatus AtfA-D transcription factors (TFs) characterizing possible genetic and physical interactions between them after normal growth and stressing conditions. We constructed double null mutants for all the possible combinations of ΔatfA-, -B, -C, and -D, and look into their susceptibility to different stressing conditions. Our results indicate complex genetic interactions among these TFs that could impact the response to different kinds of stressful conditions. AtfA-D interactions also affect the A. fumigatus virulence in Galleria mellonella. AtfA:GFP is ~97% located in the nucleus while about 20-30% of AtfB, -C, and -D:GFP locate into the nucleus in the absence of any stress. Under stressing conditions, AtfB, -C, and -D:GFP translocate to the nucleus about 60-80% upon the addition of sorbitol or H2O2. These four TFs are also interacting physically forming all the possible combinations of heterodimers. We also identified that AtfA-D physically interact with the MAPK SakA in the absence of any stress and upon osmotic and cell wall stresses. They are involved in the accumulation of trehalose, glycogen and metabolic assimilation of different carbon sources.
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Affiliation(s)
| | | | - Gustavo Henrique Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
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Extracellular Vesicles from Sporothrix Yeast Cells. Curr Top Microbiol Immunol 2021; 432:35-44. [DOI: 10.1007/978-3-030-83391-6_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Herrero-de-Dios C, Román E, Pla J, Alonso-Monge R. Hog1 Controls Lipids Homeostasis Upon Osmotic Stress in Candida albicans. J Fungi (Basel) 2020; 6:jof6040355. [PMID: 33321998 PMCID: PMC7770603 DOI: 10.3390/jof6040355] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 11/28/2020] [Accepted: 12/08/2020] [Indexed: 12/02/2022] Open
Abstract
As opportunistic pathogen, Candida albicans adapts to different environmental conditions and its corresponding stress. The Hog1 MAPK (Mitogen Activated Protein Kinase) was identified as the main MAPK involved in the response to osmotic stress. It was later shown that this MAPK is also involved in the response to a variety of stresses and therefore, its role in virulence, survival to phagocytes and establishment as commensal in the mouse gastrointestinal tract was reported. In this work, the role of Hog1 in osmotic stress is further analyzed, showing that this MAPK is involved in lipid homeostasis. The hog1 mutant accumulates lipid droplets when exposed to osmotic stress, leading to an increase in cell permeability and delaying the endocytic trafficking routes. Cek1, a MAPK also implicated in the response to osmotic challenge, did not play a role in lipid homeostasis indicating that Hog1 is the main MAP kinase in this response. The alteration on lipid metabolism observed in hog1 mutants is proposed to contribute to the sensitivity to osmotic stress.
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Affiliation(s)
- Carmen Herrero-de-Dios
- Servicio de Bioquímica, Hospital Universitario Ramón y Cajal, Ctra. Colmenar Km 9, 28034 Madrid, Spain;
| | - Elvira Román
- Departamento de Microbiología y Parasitología-IRYCIS, Facultad de Farmacia, Universidad Complutense de Madrid, Plaza de Ramón y Cajal s/n, 28040 Madrid, Spain; (E.R.); (J.P.)
| | - Jesús Pla
- Departamento de Microbiología y Parasitología-IRYCIS, Facultad de Farmacia, Universidad Complutense de Madrid, Plaza de Ramón y Cajal s/n, 28040 Madrid, Spain; (E.R.); (J.P.)
| | - Rebeca Alonso-Monge
- Departamento de Microbiología y Parasitología-IRYCIS, Facultad de Farmacia, Universidad Complutense de Madrid, Plaza de Ramón y Cajal s/n, 28040 Madrid, Spain; (E.R.); (J.P.)
- Correspondence: ; Tel.: +34-91-394-1888
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Moreno-Ruiz D, Fuchs A, Missbach K, Schuhmacher R, Zeilinger S. Influence of Different Light Regimes on the Mycoparasitic Activity and 6-Pentyl-α-pyrone Biosynthesis in Two Strains of Trichoderma atroviride. Pathogens 2020; 9:pathogens9100860. [PMID: 33096850 PMCID: PMC7589932 DOI: 10.3390/pathogens9100860] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 10/14/2020] [Accepted: 10/19/2020] [Indexed: 01/09/2023] Open
Abstract
The ascomycete Trichoderma atroviride is well known for its mycoparasitic lifestyle. Similar to other organisms, light is an important cue for T. atroviride. However, besides triggering of conidiation, little is known on the physiological responses of T. atroviride to light. In this study, we analyzed how cultivation under different light wavelengths and regimes impacted the behavior of two T. atroviride wild-type strains: IMI206040 and P1. While colony extension of both strains was slightly affected by light, massive differences in their photoconidation responses became evident. T. atroviride P1 colonies conidiated under all conditions tested including growth in complete darkness, while IMI206040 required white, blue or green light to trigger asexual reproduction. Interestingly, deletion of the stress-activated MAP kinase-encoding gene tmk3 abolished the ability of strain P1 to conidiate in red and yellow light as well as in darkness. Furthermore, light-dependent differences in the mycoparasitic activity and in the biosynthesis of the secondary metabolite 6-pentyl-α-pyrone (6-PP) became evident. 6-PP production was highest upon dark incubation, while light, especially exposure to white light as light/dark cycles, had an inhibitory effect on its biosynthesis. We conclude that the response of T. atroviride to light is strain-dependent and impacts differentiation, mycoparasitism, and 6-PP production; hence, this should be considered in experiments testing the mycoparasitic activity of these fungi.
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Affiliation(s)
- Dubraska Moreno-Ruiz
- Department of Microbiology, University of Innsbruck, 6020 Innsbruck, Austria; (D.M.-R.); (A.F.)
| | - Alessandro Fuchs
- Department of Microbiology, University of Innsbruck, 6020 Innsbruck, Austria; (D.M.-R.); (A.F.)
| | - Kristina Missbach
- Department of Agrobiotechnology (IFA-Tulln), University of Natural Resources and Life Sciences Vienna (BOKU), 1180 Tulln, Austria; (K.M.); (R.S.)
| | - Rainer Schuhmacher
- Department of Agrobiotechnology (IFA-Tulln), University of Natural Resources and Life Sciences Vienna (BOKU), 1180 Tulln, Austria; (K.M.); (R.S.)
| | - Susanne Zeilinger
- Department of Microbiology, University of Innsbruck, 6020 Innsbruck, Austria; (D.M.-R.); (A.F.)
- Correspondence:
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Correia I, Wilson D, Hube B, Pla J. Characterization of a Candida albicans Mutant Defective in All MAPKs Highlights the Major Role of Hog1 in the MAPK Signaling Network. J Fungi (Basel) 2020; 6:jof6040230. [PMID: 33080787 PMCID: PMC7711971 DOI: 10.3390/jof6040230] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 10/12/2020] [Accepted: 10/14/2020] [Indexed: 12/16/2022] Open
Abstract
The success of Candida albicans as a pathogen relies on its ability to adapt and proliferate in different environmental niches. Pathways regulated by mitogen-activated protein kinases (MAPKs) are involved in sensing environmental conditions and developing an accurate adaptive response. Given the frequent cooperative roles of these routes in cellular functions, we have generated mutants defective in all combinations of the four described MAPKs in C. albicans and characterized its phenotype regarding sensitiveness to specific drugs, morphogenesis and interaction with host immune cells. We demonstrate that all MAPKs are dispensable in this yeast as a mutant defective in Cek1, Cek2, Mkc1 and Hog1 is viable although highly sensitive to oxidative and osmotic stress, displaying a specific pattern of sensitivity to antifungals. By comparing its phenotype with single, double and triple combinations of MAPK-deletion mutants we were able to unveil a Cek1-independent mechanism for Hog1 resistance to Congo red, and confirm the predominant effect of Hog1 on oxidative and osmotic adaptation. The quadruple mutant produces filaments under non-inducing conditions, but is unable to develop chlamydospores. Furthermore, cek1 cek2 mkc1 hog1 cells switch to the opaque state at high frequency, which is blocked by the ectopic expression of HOG1 suggesting a role of this kinase for phenotypic switching.
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Affiliation(s)
- Inês Correia
- iBiMED-Institute of Biomedicine, Department of Medical Sciences, University of Aveiro, Agra do Crasto, 3810-193 Aveiro, Portugal
- Correspondence: (I.C.); (J.P.); Tel.: +351-234-370-213 (I.C.); +34-913-941-617 (J.P.)
| | - Duncan Wilson
- Medical Research Council Centre for Medical Mycology, School of Biosciences, University of Exeter, Exeter EX4 4QD, UK;
| | - Bernhard Hube
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology-Hans-Knoell-Institute, Beutenbergstraße 11A, 07745 Jena, Germany;
- Institute of Microbiology, Friedrich Schiller University, Neugasse 25, 07743 Jena, Germany
| | - Jesús Pla
- Departamento de Microbiología y Parasitología-IRYCIS, Facultad de Farmacia, Universidad Complutense de Madrid, Avda. Ramón y Cajal s/n, 28040 Madrid, Spain
- Correspondence: (I.C.); (J.P.); Tel.: +351-234-370-213 (I.C.); +34-913-941-617 (J.P.)
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The Two-Component Response Regulator Ssk1 and the Mitogen-Activated Protein Kinase Hog1 Control Antifungal Drug Resistance and Cell Wall Architecture of Candida auris. mSphere 2020; 5:5/5/e00973-20. [PMID: 33055262 PMCID: PMC7565899 DOI: 10.1128/msphere.00973-20] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Candida auris is an emerging multidrug-resistant (MDR) fungal pathogen that presents a serious global threat to human health. The Centers for Disease Control and Prevention (CDC) have classified C. auris as an urgent threat to public health for the next decade due to its major clinical and economic impact and the lack of effective antifungal drugs and because of future projections concerning new C. auris infections. Importantly, the Global Antimicrobial Resistance Surveillance System (GLASS) has highlighted the need for more robust and efficacious global surveillance schemes enabling the identification and monitoring of antifungal resistance in Candida infections. Despite the clinical relevance of C. auris infections, our overall understanding of its pathophysiology and virulence, its response to human immune surveillance, and the molecular basis of multiple antifungal resistance remains in its infancy. Here, we show a marked phenotypic plasticity of C. auris clinical isolates. Further, we demonstrate critical roles of stress response mechanisms in regulating multidrug resistance and show that cell wall architecture and composition are key elements that determine antifungal drug susceptibilities. Our data promise new therapeutic options to treat drug-refractory C. auris infections. Candida auris is an emerging multidrug-resistant human fungal pathogen refractory to treatment by several classes of antifungal drugs. Unlike other Candida species, C. auris can adhere to human skin for prolonged periods of time, allowing for efficient skin-to-skin transmission in the hospital environments. However, molecular mechanisms underlying pronounced multidrug resistance and adhesion traits are poorly understood. Two-component signal transduction and mitogen-activated protein (MAP) kinase signaling are important regulators of adherence, antifungal drug resistance, and virulence. Here, we report that genetic removal of SSK1 encoding a response regulator and the mitogen-associated protein kinase HOG1 restores the susceptibility to both amphotericin B (AMB) and caspofungin (CAS) in C. auris clinical strains. The loss of SSK1 and HOG1 alters membrane lipid permeability, cell wall mannan content, and hyperresistance to cell wall-perturbing agents. Interestingly, our data reveal variable functions of SSK1 and HOG1 in different C. auris clinical isolates, suggesting a pronounced genetic plasticity affecting cell wall function, stress adaptation, and multidrug resistance. Taken together, our data suggest that targeting two-component signal transduction systems could be suitable for restoring C. auris susceptibility to antifungal drugs. IMPORTANCECandida auris is an emerging multidrug-resistant (MDR) fungal pathogen that presents a serious global threat to human health. The Centers for Disease Control and Prevention (CDC) have classified C. auris as an urgent threat to public health for the next decade due to its major clinical and economic impact and the lack of effective antifungal drugs and because of future projections concerning new C. auris infections. Importantly, the Global Antimicrobial Resistance Surveillance System (GLASS) has highlighted the need for more robust and efficacious global surveillance schemes enabling the identification and monitoring of antifungal resistance in Candida infections. Despite the clinical relevance of C. auris infections, our overall understanding of its pathophysiology and virulence, its response to human immune surveillance, and the molecular basis of multiple antifungal resistance remains in its infancy. Here, we show a marked phenotypic plasticity of C. auris clinical isolates. Further, we demonstrate critical roles of stress response mechanisms in regulating multidrug resistance and show that cell wall architecture and composition are key elements that determine antifungal drug susceptibilities. Our data promise new therapeutic options to treat drug-refractory C. auris infections.
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Putative Membrane Receptors Contribute to Activation and Efficient Signaling of Mitogen-Activated Protein Kinase Cascades during Adaptation of Aspergillus fumigatus to Different Stressors and Carbon Sources. mSphere 2020; 5:5/5/e00818-20. [PMID: 32938702 PMCID: PMC7494837 DOI: 10.1128/msphere.00818-20] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The high-osmolarity glycerol (HOG) response pathway is a multifunctional signal transduction pathway that specifically transmits ambient osmotic signals. Saccharomyces cerevisiae Hog1p has two upstream signaling branches, the sensor histidine kinase Sln1p and the receptor Sho1p. The Sho1p branch includes two other proteins, the Msb2p mucin and Opy2p. Aspergillus fumigatus is the leading cause of pulmonary fungal diseases. Here, we investigated the roles played by A. fumigatus SlnASln1p, ShoASho1p, MsbAMsb2p, and OpyAOpy2p putative homologues during the activation of the mitogen-activated protein kinase (MAPK) HOG pathway. The shoA, msbA, and opyA singly and doubly null mutants are important for the cell wall integrity (CWI) pathway, oxidative stress, and virulence as assessed by a Galleria mellonella model. Genetic interactions of ShoA, MsbA, and OpyA are also important for proper activation of the SakAHog1p and MpkASlt2 cascade and the response to osmotic and cell wall stresses. Comparative label-free quantitative proteomics analysis of the singly null mutants with the wild-type strain upon caspofungin exposure indicates that the absence of ShoA, MsbA, and OpyA affects the osmotic stress response, carbohydrate metabolism, and protein degradation. The putative receptor mutants showed altered trehalose and glycogen accumulation, suggesting a role for ShoA, MsbA, and OpyA in sugar storage. Protein kinase A activity was also decreased in these mutants. We also observed genetic interactions between SlnA, ShoA, MsbA, and OpyA, suggesting that both branches are important for activation of the HOG/CWI pathways. Our results help in the understanding of the activation and modulation of the HOG and CWI pathways in this important fungal pathogen.IMPORTANCE Aspergillus fumigatus is an important human-pathogenic fungal species that is responsible for a high incidence of infections in immunocompromised individuals. A. fumigatus high-osmolarity glycerol (HOG) and cell wall integrity pathways are important for the adaptation to different forms of environmental adversity such as osmotic and oxidative stresses, nutrient limitations, high temperatures, and other chemical and mechanical stresses that may be produced by the host immune system and antifungal drugs. Little is known about how these pathways are activated in this fungal pathogen. Here, we characterize four A. fumigatus putative homologues that are important for the activation of the yeast HOG pathway. A. fumigatus SlnASln1p, ShoASho1p, MsbAMsb2p, and OpyAOpy2p are genetically interacting and are essential for the activation of the HOG and cell wall integrity pathways. Our results contribute to the understanding of A. fumigatus adaptation to the host environment.
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Lighting Conditions Influence the Dynamics of Protease Synthesis and Proteasomal Activity in the White Rot Fungus Cerrena unicolor. Biomolecules 2020; 10:biom10091322. [PMID: 32942733 PMCID: PMC7565922 DOI: 10.3390/biom10091322] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 09/09/2020] [Accepted: 09/14/2020] [Indexed: 01/25/2023] Open
Abstract
Recent transcriptomic and biochemical studies have revealed that light influences the global gene expression profile and metabolism of the white-rot fungus Cerrena unicolor. Here, we aimed to reveal the involvement of proteases and ubiquitin-mediated proteolysis by the 26S proteasome in the response of this fungus to white, red, blue and green lighting conditions and darkness. The changes in the expression profile of C. unicolor genes putatively engaged in proteolysis were found to be unique and specific to the applied wavelength of light. It was also demonstrated that the activity of proteases in the culture fluid and mycelium measured using natural and synthetic substrates was regulated by light and was substrate-dependent. A clear influence of light on protein turnover and the qualitative and quantitative changes in the hydrolytic degradation of proteins catalyzed by various types of proteases was shown. The analysis of activity associated with the 26S proteasome showed a key role of ATP-dependent proteolysis in the initial stages of adaptation of fungal cells to the stress factors. It was suggested that the light-sensing pathways in C. unicolor are cross-linked with stress signaling and secretion of proteases presumably serving as regulatory molecules.
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LeBlanc EV, Polvi EJ, Veri AO, Privé GG, Cowen LE. Structure-guided approaches to targeting stress responses in human fungal pathogens. J Biol Chem 2020; 295:14458-14472. [PMID: 32796038 DOI: 10.1074/jbc.rev120.013731] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 08/11/2020] [Indexed: 11/06/2022] Open
Abstract
Fungi inhabit extraordinarily diverse ecological niches, including the human body. Invasive fungal infections have a devastating impact on human health worldwide, killing ∼1.5 million individuals annually. The majority of these deaths are attributable to species of Candida, Cryptococcus, and Aspergillus Treating fungal infections is challenging, in part due to the emergence of resistance to our limited arsenal of antifungal agents, necessitating the development of novel therapeutic options. Whereas conventional antifungal strategies target proteins or cellular components essential for fungal growth, an attractive alternative strategy involves targeting proteins that regulate fungal virulence or antifungal drug resistance, such as regulators of fungal stress responses. Stress response networks enable fungi to adapt, grow, and cause disease in humans and include regulators that are highly conserved across eukaryotes as well as those that are fungal-specific. This review highlights recent developments in elucidating crystal structures of fungal stress response regulators and emphasizes how this knowledge can guide the design of fungal-selective inhibitors. We focus on the progress that has been made with highly conserved regulators, including the molecular chaperone Hsp90, the protein phosphatase calcineurin, and the small GTPase Ras1, as well as with divergent stress response regulators, including the cell wall kinase Yck2 and trehalose synthases. Exploring structures of these important fungal stress regulators will accelerate the design of selective antifungals that can be deployed to combat life-threatening fungal diseases.
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Affiliation(s)
- Emmanuelle V LeBlanc
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Elizabeth J Polvi
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Amanda O Veri
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Gilbert G Privé
- Departments of Medical Biophysics and Biochemistry, University of Toronto, Toronto, Ontario, Canada.,Princess Margaret Cancer Centre, Toronto, Ontario, Canada
| | - Leah E Cowen
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
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Sho1p Connects Glycolysis to Ras1-cAMP Signaling and Is Required for Microcolony Formation in Candida albicans. mSphere 2020; 5:5/4/e00366-20. [PMID: 32641426 PMCID: PMC7343979 DOI: 10.1128/msphere.00366-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
C. albicans microcolonies form extensive hyphal structures that enhance surface adherence and penetrate underlying tissues to promote fungal infections. This study examined the environmental conditions that promote microcolony formation and how these signals are relayed, in order to disrupt signaling and reduce pathogenesis. We found that a membrane-localized protein, Sho1, is an upstream regulator of glycolysis and required for Ras1-cAMP signaling. Sho1 controlled the Ras1-dependent expression of core microcolony genes involved in adhesion and virulence. This new regulatory function for Sho1 linking glycolysis to microcolony formation reveals a novel role for this fungal membrane protein. Candida albicans is an opportunistic, dimorphic fungus that causes candidiasis in immunocompromised people. C. albicans forms specialized structures called microcolonies that are important for surface adhesion and virulence. Microcolonies form in response to specific environmental conditions and require glycolytic substrates for optimal growth. However, fungal signaling pathways involved in sensing and transmitting these environmental cues to induce microcolony formation have not been identified. Here, we show that the C. albicans Ras1-cAMP cascade is required for microcolony formation, while the Cek1-MAP kinase pathway is not required, and Hog1 represses microcolony formation. The membrane protein Sho1, known to regulate the Cek1 pathway in yeasts, was indispensable for C. albicans microcolony formation but regulated the Ras1-cAMP pathway instead, based upon diminished intracellular levels of cAMP and reduced expression of core microcolony genes, including HWP1, PGA10, and ECE1, in C. albicanssho1Δ cells. Based upon predicted physical interactions between Sho1 and the glycolytic enzymes Pfk1, Fba1, Pgk1, and Cdc19, we hypothesized that Sho1 regulates Ras1-cAMP by establishing cellular energy levels produced by glycolysis. Indeed, microcolony formation was restored in C. albicanssho1Δ cells by addition of exogenous intermediates of glycolysis, including downstream products of each predicted interacting enzyme (fructose 1,6 bisphosphate, glyceraldehyde phosphate, 3-phosphoglyceric acid, and pyruvate). Thus, C. albicans Sho1 is an upstream regulator of the Ras1-cAMP signaling pathway that connects glycolytic metabolism to the formation of pathogenic microcolonies. IMPORTANCEC. albicans microcolonies form extensive hyphal structures that enhance surface adherence and penetrate underlying tissues to promote fungal infections. This study examined the environmental conditions that promote microcolony formation and how these signals are relayed, in order to disrupt signaling and reduce pathogenesis. We found that a membrane-localized protein, Sho1, is an upstream regulator of glycolysis and required for Ras1-cAMP signaling. Sho1 controlled the Ras1-dependent expression of core microcolony genes involved in adhesion and virulence. This new regulatory function for Sho1 linking glycolysis to microcolony formation reveals a novel role for this fungal membrane protein.
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Schumacher J, Gorbushina AA. Light sensing in plant- and rock-associated black fungi. Fungal Biol 2020; 124:407-417. [DOI: 10.1016/j.funbio.2020.01.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 01/09/2020] [Accepted: 01/17/2020] [Indexed: 01/24/2023]
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Cooperative Role of MAPK Pathways in the Interaction of Candida albicans with the Host Epithelium. Microorganisms 2019; 8:microorganisms8010048. [PMID: 31881718 PMCID: PMC7023383 DOI: 10.3390/microorganisms8010048] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 12/09/2019] [Accepted: 12/24/2019] [Indexed: 12/17/2022] Open
Abstract
Candida albicans is an important human fungal pathogen responsible for tens of millions of infections as well as hundreds of thousands of severe life-threatening infections each year. MAP kinase (MAPK) signal transduction pathways facilitate the sensing and adaptation to external stimuli and control the expression of key virulence factors such as the yeast-to-hypha transition, the biogenesis of the cell wall, and the interaction with the host. In the present study, we have combined molecular approaches and infection biology to analyse the role of C. albicans MAPK pathways during an epithelial invasion. Hog1 was found to be important for adhesion to abiotic surfaces but was dispensable for damage to epithelial cells. The Mkc1 cell wall integrity (CWI) and Cek1 pathways, on the other hand, were both required for oral epithelial damage. Analysis of the ability to penetrate nutrient-rich semi-solid media revealed a cooperative role for Cek1 and Mkc1 in this process. Finally, cek2Δ (as well as cek1Δ) but not mkc1Δ or hog1Δ mutants, exhibited elevated β-glucan unmasking as revealed by immunofluorescence studies. Therefore, the four MAPK pathways play distinct roles in adhesion, epithelial damage, invasion and cell wall remodelling that may contribute to the pathogenicity of C. albicans.
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Deletion of the SKO1 Gene in a hog1 Mutant Reverts Virulence in Candida albicans. J Fungi (Basel) 2019; 5:jof5040107. [PMID: 31731583 PMCID: PMC6958353 DOI: 10.3390/jof5040107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 11/07/2019] [Accepted: 11/13/2019] [Indexed: 11/18/2022] Open
Abstract
Candida albicans displays the ability to adapt to a wide variety of environmental conditions, triggering signaling pathways and transcriptional regulation. Sko1 is a transcription factor that was previously involved in early hypoxic response, cell wall remodeling, and stress response. In the present work, the role of sko1 mutant in in vivo and ex vivo studies was explored. The sko1 mutant behaved as its parental wild type strain regarding the ability to colonize murine intestinal tract, ex vivo adhesion to murine gut epithelium, or systemic virulence. These observations suggest that Sko1 is expendable during commensalism or pathogenesis. Nevertheless, the study of the hog1 sko1 double mutant showed unexpected phenotypes. Previous researches reported that the deletion of the HOG1 gene led to avirulent C. albicans mutant cell, which was, therefore, unable to establish as a commensal in a gastrointestinal murine model. Here, we show that the deletion of sko1 in a hog1 background reverted the virulence of the hog1 mutant in a systemic infection model in Galleria mellonella larvae and slightly improved the ability to colonize the murine gut in a commensalism animal model compared to the hog1 mutant. These results indicate that Sko1 acts as a repressor of virulence related genes, concluding that Sko1 plays a relevant role during commensalism and systemic infection.
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