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Liu D, Garrigues S, Culleton H, McKie VA, de Vries RP. Analysis of the molecular basis for the non-amylolytic and non-proteolytic nature of Aspergillus vadensis CBS 113365. N Biotechnol 2024; 82:25-32. [PMID: 38697469 DOI: 10.1016/j.nbt.2024.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 04/01/2024] [Accepted: 04/29/2024] [Indexed: 05/05/2024]
Abstract
Aspergillus vadensis CBS 113365, a close relative of A. niger, has been suggested as a more favourable alternative for recombinant protein production as it does not acidify the culture medium and produces very low levels of extracellular proteases. The aim of this study was to investigate the underlying cause of the non-amylolytic and non-proteolytic phenotype of A. vadensis CBS 113365. Our results demonstrate that the non-functionality of the amylolytic transcription factor AmyR in A. vadensis CBS 113365 is primarily attributed to the lack of functionality of its gene's promoter sequence. In contrast, a different mechanism is likely causing the lack of PrtT activity, which is the main transcriptional regulator of protease production. The findings presented here not only expand our understanding of the genetic basis behind the distinct characteristics of A. vadensis CBS 113365, but also underscore its potential as a favourable alternative for recombinant protein production.
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Affiliation(s)
- Dujuan Liu
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, the Netherlands
| | - Sandra Garrigues
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, the Netherlands; Departament of Food Biotechnology, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Paterna, Valencia, Spain
| | - Helena Culleton
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, the Netherlands; Megazyme International Ireland, Bray, Co. Wicklow, Ireland
| | | | - Ronald P de Vries
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, the Netherlands.
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2
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Curtis A, Dobes P, Marciniak J, Hurychova J, Hyrsl P, Kavanagh K. Characterization of Aspergillus fumigatus secretome during sublethal infection of Galleria mellonella larvae. J Med Microbiol 2024; 73:001844. [PMID: 38836745 PMCID: PMC11261830 DOI: 10.1099/jmm.0.001844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Accepted: 05/17/2024] [Indexed: 06/06/2024] Open
Abstract
Introduction. The fungal pathogen Aspergillus fumigatus can induce prolonged colonization of the lungs of susceptible patients, resulting in conditions such as allergic bronchopulmonary aspergillosis and chronic pulmonary aspergillosis.Hypothesis. Analysis of the A. fumigatus secretome released during sub-lethal infection of G. mellonella larvae may give an insight into products released during prolonged human colonisation.Methodology. Galleria mellonella larvae were infected with A. fumigatus, and the metabolism of host carbohydrate and proteins and production of fungal virulence factors were analysed. Label-free qualitative proteomic analysis was performed to identify fungal proteins in larvae at 96 hours post-infection and also to identify changes in the Galleria proteome as a result of infection.Results. Infected larvae demonstrated increasing concentrations of gliotoxin and siderophore and displayed reduced amounts of haemolymph carbohydrate and protein. Fungal proteins (399) were detected by qualitative proteomic analysis in cell-free haemolymph at 96 hours and could be categorized into seven groups, including virulence (n = 25), stress response (n = 34), DNA repair and replication (n = 39), translation (n = 22), metabolism (n = 42), released intracellular (n = 28) and cellular development and cell cycle (n = 53). Analysis of the Gallerial proteome at 96 hours post-infection revealed changes in the abundance of proteins associated with immune function, metabolism, cellular structure, insect development, transcription/translation and detoxification.Conclusion. Characterizing the impact of the fungal secretome on the host may provide an insight into how A. fumigatus damages tissue and suppresses the immune response during long-term pulmonary colonization.
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Affiliation(s)
- Aaron Curtis
- Department of Biology, Maynooth University, Maynooth, Co. Kildare, Ireland
| | - Pavel Dobes
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Jacek Marciniak
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Jana Hurychova
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Pavel Hyrsl
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Kevin Kavanagh
- Department of Biology, Maynooth University, Maynooth, Co. Kildare, Ireland
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3
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Kerkaert JD, Huberman LB. Regulation of nutrient utilization in filamentous fungi. Appl Microbiol Biotechnol 2023; 107:5873-5898. [PMID: 37540250 PMCID: PMC10983054 DOI: 10.1007/s00253-023-12680-4] [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: 04/19/2023] [Revised: 06/29/2023] [Accepted: 07/04/2023] [Indexed: 08/05/2023]
Abstract
Organisms must accurately sense and respond to nutrients to survive. In filamentous fungi, accurate nutrient sensing is important in the establishment of fungal colonies and in continued, rapid growth for the exploitation of environmental resources. To ensure efficient nutrient utilization, fungi have evolved a combination of activating and repressing genetic networks to tightly regulate metabolic pathways and distinguish between preferred nutrients, which require minimal energy and resources to utilize, and nonpreferred nutrients, which have more energy-intensive catabolic requirements. Genes necessary for the utilization of nonpreferred carbon sources are activated by transcription factors that respond to the presence of the specific nutrient and repressed by transcription factors that respond to the presence of preferred carbohydrates. Utilization of nonpreferred nitrogen sources generally requires two transcription factors. Pathway-specific transcription factors respond to the presence of a specific nonpreferred nitrogen source, while another transcription factor activates genes in the absence of preferred nitrogen sources. In this review, we discuss the roles of transcription factors and upstream regulatory genes that respond to preferred and nonpreferred carbon and nitrogen sources and their roles in regulating carbon and nitrogen catabolism. KEY POINTS: • Interplay of activating and repressing transcriptional networks regulates catabolism. • Nutrient-specific activating transcriptional pathways provide metabolic specificity. • Repressing regulatory systems differentiate nutrients in mixed nutrient environments.
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Affiliation(s)
- Joshua D Kerkaert
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, USA
| | - Lori B Huberman
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, USA.
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4
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Yoshimura Y, Kobayashi Y, Kawaguchi T, Tani S. Improvement of cellulosic biomass-degrading enzyme production by reducing extracellular protease production in <i>Aspergillus aculeatus</i>. J GEN APPL MICROBIOL 2022; 68:143-150. [DOI: 10.2323/jgam.2021.10.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Yuko Yoshimura
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University
| | - Yuri Kobayashi
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University
| | - Takashi Kawaguchi
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University
| | - Shuji Tani
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University
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5
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Nitrogen, Iron and Zinc Acquisition: Key Nutrients to Aspergillus fumigatus Virulence. J Fungi (Basel) 2021; 7:jof7070518. [PMID: 34203370 PMCID: PMC8303583 DOI: 10.3390/jof7070518] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 06/24/2021] [Accepted: 06/24/2021] [Indexed: 12/31/2022] Open
Abstract
Aspergillus fumigatus is a ubiquitous soil decomposer and an opportunistic pathogen that is characterized by its large metabolic machinery for acquiring nutrients from media. Lately, an ever-increasing number of genes involved in fungal nutrition has been associated with its virulence. Of these, nitrogen, iron, and zinc metabolism-related genes are particularly noteworthy, since 78% of them have a direct implication in virulence. In this review, we describe the sensing, uptake and regulation process of the acquisition of these nutrients, the connections between pathways and the virulence-implicated genes. Nevertheless, only 40% of the genes mentioned in this review have been assayed for roles in virulence, leaving a wide field of knowledge that remains uncertain and might offer new therapeutic and diagnostic targets.
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Misslinger M, Hortschansky P, Brakhage AA, Haas H. Fungal iron homeostasis with a focus on Aspergillus fumigatus. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1868:118885. [PMID: 33045305 DOI: 10.1016/j.bbamcr.2020.118885] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 09/15/2020] [Accepted: 10/01/2020] [Indexed: 02/08/2023]
Abstract
To maintain iron homeostasis, fungi have to balance iron acquisition, storage, and utilization to ensure sufficient supply and to avoid toxic excess of this essential trace element. As pathogens usually encounter iron limitation in the host niche, this metal plays a particular role during virulence. Siderophores are iron-chelators synthesized by most, but not all fungal species to sequester iron extra- and intracellularly. In recent years, the facultative human pathogen Aspergillus fumigatus has become a model for fungal iron homeostasis of siderophore-producing fungal species. This article summarizes the knowledge on fungal iron homeostasis and its links to virulence with a focus on A. fumigatus. It covers mechanisms for iron acquisition, storage, and detoxification, as well as the modes of transcriptional iron regulation and iron sensing in A. fumigatus in comparison to other fungal species. Moreover, potential translational applications of the peculiarities of fungal iron metabolism for treatment and diagnosis of fungal infections is addressed.
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Affiliation(s)
- Matthias Misslinger
- Institute of Molecular Biology - Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Peter Hortschansky
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute (HKI), Jena, Germany
| | - Axel A Brakhage
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute (HKI), Jena, Germany; Department Microbiology and Molecular Biology, Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
| | - Hubertus Haas
- Institute of Molecular Biology - Biocenter, Medical University of Innsbruck, Innsbruck, Austria.
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7
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Huang L, Dong L, Wang B, Pan L. The transcription factor PrtT and its target protease profiles in Aspergillus niger are negatively regulated by carbon sources. Biotechnol Lett 2020; 42:613-624. [PMID: 31970554 DOI: 10.1007/s10529-020-02806-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2019] [Accepted: 01/13/2020] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To survey genome-scale protease profiles regulated by the Aspergillus niger transcription factor PrtT and further controlled by carbon sources. RESULTS The PrtT disruption mutant (delprtT) and overexpression (OEprtT) strains were successfully generated and further confirmed by phenotypic and protease activity analysis. RNA-seq analysis of WT and mutants identified 32 differentially expressed protease genes, which mostly belonged to serine-type peptidases, aspartic-type endopeptidases, aminopeptidases and carboxypeptidases. Furthermore, based on the MEME predicted motif analysis of the PrtT promoter, EMSA and phenotypic and qRT-PCR analyses confirmed that the carbon metabolism regulator AmyR directly regulated the protease genes and their regulatory factor PrtT. CONCLUSION Thirty-two PrtT-regulated protease genes were identified by RNA-seq, and the secondary carbon source regulator AmyR was found to have a negative regulatory effect on the expression of PrtT and its target protease genes.
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Affiliation(s)
- Lianggang Huang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou Higher Education Mega Center, No. 382, Waihuan East Rd, Guangzhou, 510006, China
| | - Liangbo Dong
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou Higher Education Mega Center, No. 382, Waihuan East Rd, Guangzhou, 510006, China
| | - Bin Wang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou Higher Education Mega Center, No. 382, Waihuan East Rd, Guangzhou, 510006, China.,Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou, 510006, China
| | - Li Pan
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou Higher Education Mega Center, No. 382, Waihuan East Rd, Guangzhou, 510006, China. .,Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou, 510006, China.
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Fonseca LM, Parreiras LS, Murakami MT. Rational engineering of the Trichoderma reesei RUT-C30 strain into an industrially relevant platform for cellulase production. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:93. [PMID: 32461765 PMCID: PMC7243233 DOI: 10.1186/s13068-020-01732-w] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 05/14/2020] [Indexed: 05/07/2023]
Abstract
BACKGROUND The path for the development of hypersecreting strains of Trichoderma reesei capable of producing industrially relevant enzyme titers remains elusive despite over 70 years of research and industrial utilization. Herein, we describe the rational engineering of the publicly available T. reesei RUT-C30 strain and a customized process for cellulase production based on agroindustrial by-products. RESULTS A CRISPR/Cas9 system was used to introduce six genetic modifications in RUT-C30. Implemented changes included the constitutive expression of a mutated allele of the cellulase master regulator XYR1, the expression of two heterologous enzymes, the β-glucosidase CEL3A from Talaromyces emersonii and the invertase SUC1 from Aspergillus niger, and the deletion of genes encoding the cellulase repressor ACE1 and the extracellular proteases SLP1 and PEP1. These alterations resulted in a remarkable increase of protein secretion rates by RUT-C30 and amended its well described β-glucosidase deficiency while enabling the utilization of sucrose and eliminating the requirement of inducing sugars for enzyme production. With a developed sugarcane molasses-based bioprocess, the engineered strain reached an extracellular protein titer of 80.6 g L-1 (0.24 g L-1 h-1), which is the highest experimentally supported titer so far reported for T. reesei. The produced enzyme cocktail displayed increased levels of cellulase and hemicellulase activities, with particularly large increments being observed for the specific activities of β-glucosidase (72-fold) and xylanase (42-fold). Notably, it also exhibited a saccharification efficiency similar to that of a commercially available cellulase preparation in the deconstruction of industrially pretreated sugarcane straw. CONCLUSION This work demonstrates the rational steps for the development of a cellulase hyperproducing strain from a well-characterized genetic background available in the public domain, the RUT-C30, associated with an industrially relevant bioprocess, paving new perspectives for Trichoderma research on cellulase production.
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Affiliation(s)
- Lucas Miranda Fonseca
- Brazilian Biorenewables National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, São Paulo 13083-100 Brazil
| | - Lucas Salera Parreiras
- Brazilian Biorenewables National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, São Paulo 13083-100 Brazil
| | - Mario Tyago Murakami
- Brazilian Biorenewables National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, São Paulo 13083-100 Brazil
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Ballester AR, López-Pérez M, de la Fuente B, González-Candelas L. Functional and Pharmacological Analyses of the Role of Penicillium digitatum Proteases on Virulence. Microorganisms 2019; 7:microorganisms7070198. [PMID: 31336863 PMCID: PMC6680461 DOI: 10.3390/microorganisms7070198] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 07/08/2019] [Accepted: 07/11/2019] [Indexed: 11/16/2022] Open
Abstract
Penicillium digitatum is the major postharvest pathogen of citrus fruit under Mediterranean climate conditions. Previous results have shown that proteases is the largest enzyme family induced by P. digitatum during fruit infection. In the present work, we addressed the study of the role of P. digitatum's proteases in virulence following two complementary approaches. In the first approach, we undertook the functional characterization of the P. digitatum prtT gene, which codes for a putative transcription factor previously shown to regulate extracellular proteases in other filamentous fungi. Deletion of prtT caused a significant loss in secreted protease activity during in vitro growth assays. However, there was no effect on virulence. Gene expression of the two major secreted acid proteases was barely affected in the ΔprtT deletant during infection of citrus fruit. Hence, no conclusion could be drawn on the role of these secreted acidic proteases on the virulence of P. digitatum. In the second approach, we studied the effect of different protease inhibitors and chelators on virulence. Co-inoculation of citrus fruit with P. digitatum conidia and a cocktail of protease inhibitors resulted in almost a complete absence of disease development. Analysis of individual inhibitors revealed that the metalloprotease inhibitor, 1,10-phenanthroline, was responsible for the observed effect. The application of metal ions reverted the protective effect caused by the metallopeptidase inhibitor. These results may set the basis for the development of new alternative treatments to combat this important postharvest pathogen.
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Affiliation(s)
- Ana-Rosa Ballester
- Department of Food Biotechnology, Institute of Agrochemistry and Food Technology, Spanish National Research Council (IATA-CSIC), Calle Catedrático Agustín Escardino 7, 46980 Paterna, Valencia, Spain
| | - Mario López-Pérez
- Department of Food Biotechnology, Institute of Agrochemistry and Food Technology, Spanish National Research Council (IATA-CSIC), Calle Catedrático Agustín Escardino 7, 46980 Paterna, Valencia, Spain
| | - Beatriz de la Fuente
- Department of Food Biotechnology, Institute of Agrochemistry and Food Technology, Spanish National Research Council (IATA-CSIC), Calle Catedrático Agustín Escardino 7, 46980 Paterna, Valencia, Spain
| | - Luis González-Candelas
- Department of Food Biotechnology, Institute of Agrochemistry and Food Technology, Spanish National Research Council (IATA-CSIC), Calle Catedrático Agustín Escardino 7, 46980 Paterna, Valencia, Spain.
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10
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Ries LNA, Steenwyk JL, de Castro PA, de Lima PBA, Almeida F, de Assis LJ, Manfiolli AO, Takahashi-Nakaguchi A, Kusuya Y, Hagiwara D, Takahashi H, Wang X, Obar JJ, Rokas A, Goldman GH. Nutritional Heterogeneity Among Aspergillus fumigatus Strains Has Consequences for Virulence in a Strain- and Host-Dependent Manner. Front Microbiol 2019; 10:854. [PMID: 31105662 PMCID: PMC6492530 DOI: 10.3389/fmicb.2019.00854] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 04/03/2019] [Indexed: 01/09/2023] Open
Abstract
Acquisition and subsequent metabolism of different carbon and nitrogen sources have been shown to play an important role in virulence attributes of the fungal pathogen Aspergillus fumigatus, such as the secretion of host tissue-damaging proteases and fungal cell wall integrity. We examined the relationship between the metabolic processes of carbon catabolite repression (CCR), nitrogen catabolite repression (NCR) and virulence in a variety of A. fumigatus clinical isolates. A considerable amount of heterogeneity with respect to the degree of CCR and NCR was observed and a positive correlation between NCR and virulence in a neutropenic mouse model of pulmonary aspergillosis (PA) was found. Isolate Afs35 was selected for further analysis and compared to the reference strain A1163, with both strains presenting the same degree of virulence in a neutropenic mouse model of PA. Afs35 metabolome analysis in physiological-relevant carbon sources indicated an accumulation of intracellular sugars that also serve as cell wall polysaccharide precursors. Genome analysis showed an accumulation of missense substitutions in the regulator of protease secretion and in genes encoding enzymes required for cell wall sugar metabolism. Based on these results, the virulence of strains Afs35 and A1163 was assessed in a triamcinolone murine model of PA and found to be significantly different, confirming the known importance of using different mouse models to assess strain-specific pathogenicity. These results highlight the importance of nitrogen metabolism for virulence and provide a detailed example of the heterogeneity that exists between A. fumigatus isolates with consequences for virulence in a strain-specific and host-dependent manner.
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Affiliation(s)
| | - Jacob L. Steenwyk
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, United States
| | - Patrícia Alves de Castro
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
| | | | - Fausto Almeida
- Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
| | - Leandro José de Assis
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
| | | | | | - Yoko Kusuya
- Medical Mycology Research Center, Chiba University, Chiba, Japan
| | - Daisuke Hagiwara
- Medical Mycology Research Center, Chiba University, Chiba, Japan
| | - Hiroki Takahashi
- Medical Mycology Research Center, Chiba University, Chiba, Japan
| | - Xi Wang
- Department of Microbiology and Immunology, Dartmouth Geisel School of Medicine, Lebanon, NH, United States
| | - Joshua J. Obar
- Department of Microbiology and Immunology, Dartmouth Geisel School of Medicine, Lebanon, NH, United States
| | - Antonis Rokas
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, United States
| | - Gustavo H. Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
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Shemesh E, Hanf B, Hagag S, Attias S, Shadkchan Y, Fichtman B, Harel A, Krüger T, Brakhage AA, Kniemeyer O, Osherov N. Phenotypic and Proteomic Analysis of the Aspergillus fumigatus Δ PrtT, Δ XprG and Δ XprG/Δ PrtT Protease-Deficient Mutants. Front Microbiol 2017; 8:2490. [PMID: 29312198 PMCID: PMC5732999 DOI: 10.3389/fmicb.2017.02490] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2017] [Accepted: 11/30/2017] [Indexed: 11/13/2022] Open
Abstract
Aspergillus fumigatus is the most common mold species to cause disease in immunocompromised patients. Infection usually begins when its spores (conidia) are inhaled into the airways, where they germinate, forming hyphae that penetrate and destroy the lungs and disseminate to other organs, leading to high mortality. The ability of hyphae to penetrate the pulmonary epithelium is a key step in the infectious process. A. fumigatus produces extracellular proteases that are thought to enhance penetration by degrading host structural barriers. This study explores the role of the A. fumigatus transcription factor XprG in controlling secreted proteolytic activity and fungal virulence. We deleted xprG, alone and in combination with prtT, a transcription factor previously shown to regulate extracellular proteolysis. xprG deletion resulted in abnormal conidiogenesis and formation of lighter colored, more fragile conidia and a moderate reduction in the ability of culture filtrates (CFs) to degrade substrate proteins. Deletion of both xprG and prtT resulted in an additive reduction, generating a mutant strain producing CF with almost no ability to degrade substrate proteins. Detailed proteomic analysis identified numerous secreted proteases regulated by XprG and PrtT, alone and in combination. Interestingly, proteomics also identified reduced levels of secreted cell wall modifying enzymes (glucanases, chitinases) and allergens following deletion of these genes, suggesting they target additional cellular processes. Surprisingly, despite the major alteration in the secretome of the xprG/prtT null mutant, including two to fivefold reductions in the level of 24 proteases, 18 glucanases, 6 chitinases, and 19 allergens, it retained wild-type virulence in murine systemic and pulmonary models of infection. This study highlights the extreme adaptability of A. fumigatus during infection based on extensive gene redundancy.
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Affiliation(s)
- Einav Shemesh
- Aspergillus and Antifungal Research Laboratory, Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Benjamin Hanf
- Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), Jena, Germany.,Institute of Microbiology, Friedrich Schiller University, Jena, Germany
| | - Shelly Hagag
- Aspergillus and Antifungal Research Laboratory, Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Shani Attias
- Aspergillus and Antifungal Research Laboratory, Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Yana Shadkchan
- Aspergillus and Antifungal Research Laboratory, Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Boris Fichtman
- Faculty of Medicine in the Galilee, Bar-Ilan University, Safed, Israel
| | - Amnon Harel
- Faculty of Medicine in the Galilee, Bar-Ilan University, Safed, Israel
| | - Thomas Krüger
- Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), Jena, Germany.,Institute of Microbiology, Friedrich Schiller University, Jena, Germany
| | - Axel A Brakhage
- Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), Jena, Germany.,Institute of Microbiology, Friedrich Schiller University, Jena, Germany
| | - Olaf Kniemeyer
- Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), Jena, Germany.,Institute of Microbiology, Friedrich Schiller University, Jena, Germany
| | - Nir Osherov
- Aspergillus and Antifungal Research Laboratory, Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
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Sui YF, Ouyang LM, Chu J, Cao WQ, liang LF, Zhuang YP, Cheng S, Norrman H, Zhang SL, zhang GY. Global transcriptional response of Aspergillus niger in the process of glucoamylase fermentation. BIORESOUR BIOPROCESS 2017. [DOI: 10.1186/s40643-017-0160-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
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13
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Moloney NM, Owens RA, Doyle S. Proteomic analysis of Aspergillus fumigatus – clinical implications. Expert Rev Proteomics 2016; 13:635-49. [DOI: 10.1080/14789450.2016.1203783] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
| | | | - Sean Doyle
- Department of Biology, Maynooth University, Maynooth, Ireland
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Landowski CP, Huuskonen A, Wahl R, Westerholm-Parvinen A, Kanerva A, Hänninen AL, Salovuori N, Penttilä M, Natunen J, Ostermeier C, Helk B, Saarinen J, Saloheimo M. Enabling Low Cost Biopharmaceuticals: A Systematic Approach to Delete Proteases from a Well-Known Protein Production Host Trichoderma reesei. PLoS One 2015; 10:e0134723. [PMID: 26309247 PMCID: PMC4550459 DOI: 10.1371/journal.pone.0134723] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 07/13/2015] [Indexed: 11/22/2022] Open
Abstract
The filamentous fungus Trichoderma reesei has tremendous capability to secrete proteins. Therefore, it would be an excellent host for producing high levels of therapeutic proteins at low cost. Developing a filamentous fungus to produce sensitive therapeutic proteins requires that protease secretion is drastically reduced. We have identified 13 major secreted proteases that are related to degradation of therapeutic antibodies, interferon alpha 2b, and insulin like growth factor. The major proteases observed were aspartic, glutamic, subtilisin-like, and trypsin-like proteases. The seven most problematic proteases were sequentially removed from a strain to develop it for producing therapeutic proteins. After this the protease activity in the supernatant was dramatically reduced down to 4% of the original level based upon a casein substrate. When antibody was incubated in the six protease deletion strain supernatant, the heavy chain remained fully intact and no degradation products were observed. Interferon alpha 2b and insulin like growth factor were less stable in the same supernatant, but full length proteins remained when incubated overnight, in contrast to the original strain. As additional benefits, the multiple protease deletions have led to faster strain growth and higher levels of total protein in the culture supernatant.
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Affiliation(s)
| | - Anne Huuskonen
- VTT Technical Research Centre of Finland, Espoo, Finland
| | | | | | | | | | | | - Merja Penttilä
- VTT Technical Research Centre of Finland, Espoo, Finland
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15
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Proteomic profiling of Botrytis cinerea conidial germination. Arch Microbiol 2014; 197:117-33. [DOI: 10.1007/s00203-014-1029-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Revised: 07/21/2014] [Accepted: 08/12/2014] [Indexed: 12/20/2022]
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Budak SO, Zhou M, Brouwer C, Wiebenga A, Benoit I, Di Falco M, Tsang A, de Vries RP. A genomic survey of proteases in Aspergilli. BMC Genomics 2014; 15:523. [PMID: 24965873 PMCID: PMC4102723 DOI: 10.1186/1471-2164-15-523] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Accepted: 06/18/2014] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Proteases can hydrolyze peptides in aqueous environments. This property has made proteases the most important industrial enzymes by taking up about 60% of the total enzyme market. Microorganisms are the main sources for industrial protease production due to their high yield and a wide range of biochemical properties. Several Aspergilli have the ability to produce a variety of proteases, but no comprehensive comparative study has been carried out on protease productivity in this genus so far. RESULTS We have performed a combined analysis of comparative genomics, proteomics and enzymology tests on seven Aspergillus species grown on wheat bran and sugar beet pulp. Putative proteases were identified by homology search and Pfam domains. These genes were then clusters based on orthology and extracellular proteases were identified by protein subcellular localization prediction. Proteomics was used to identify the secreted enzymes in the cultures, while protease essays with and without inhibitors were performed to determine the overall protease activity per protease class. All this data was then integrated to compare the protease productivities in Aspergilli. CONCLUSIONS Genomes of Aspergillus species contain a similar proportion of protease encoding genes. According to comparative genomics, proteomics and enzymatic experiments serine proteases make up the largest group in the protease spectrum across the species. In general wheat bran gives higher induction of proteases than sugar beet pulp. Interesting differences of protease activity, extracellular enzyme spectrum composition, protein occurrence and abundance were identified for species. By combining in silico and wet-lab experiments, we present the intriguing variety of protease productivity in Aspergilli.
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Affiliation(s)
- Sebnem Ozturkoglu Budak
- />CBS-KNAW Fungal Biodiversity Center, Uppsalalaan 8, Utrecht, 3584 CT The Netherlands
- />Faculty of Agriculture, Department of Dairy Technology, University of Ankara, Ankara, Turkey
- />Fungal Molecular Physiology, Utrecht University, Utrecht, The Netherlands
| | - Miaomiao Zhou
- />CBS-KNAW Fungal Biodiversity Center, Uppsalalaan 8, Utrecht, 3584 CT The Netherlands
- />Fungal Molecular Physiology, Utrecht University, Utrecht, The Netherlands
| | - Carlo Brouwer
- />CBS-KNAW Fungal Biodiversity Center, Uppsalalaan 8, Utrecht, 3584 CT The Netherlands
| | - Ad Wiebenga
- />CBS-KNAW Fungal Biodiversity Center, Uppsalalaan 8, Utrecht, 3584 CT The Netherlands
- />Fungal Molecular Physiology, Utrecht University, Utrecht, The Netherlands
| | - Isabelle Benoit
- />CBS-KNAW Fungal Biodiversity Center, Uppsalalaan 8, Utrecht, 3584 CT The Netherlands
- />Fungal Molecular Physiology, Utrecht University, Utrecht, The Netherlands
| | - Marcos Di Falco
- />Centre for Structural and Functional Genomics, Concordia University, 7141 Sherbrooke Street West, Montreal, QC H4B 1R6 Canada
| | - Adrian Tsang
- />Centre for Structural and Functional Genomics, Concordia University, 7141 Sherbrooke Street West, Montreal, QC H4B 1R6 Canada
| | - Ronald P de Vries
- />CBS-KNAW Fungal Biodiversity Center, Uppsalalaan 8, Utrecht, 3584 CT The Netherlands
- />Fungal Molecular Physiology, Utrecht University, Utrecht, The Netherlands
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Chen L, Zou G, Zhang L, de Vries RP, Yan X, Zhang J, Liu R, Wang C, Qu Y, Zhou Z. The distinctive regulatory roles of PrtT in the cell metabolism of Penicillium oxalicum. Fungal Genet Biol 2013; 63:42-54. [PMID: 24333140 DOI: 10.1016/j.fgb.2013.12.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Revised: 11/29/2013] [Accepted: 12/02/2013] [Indexed: 01/05/2023]
Abstract
PrtT is a fungal-specific transcription activator of extracellular proteases in Aspergilli. In this study, the roles of the PrtT homolog from Penicillum oxalicum was investigated by transcription profiling in combination with electrophoretic mobility shift assay (EMSA). The prtT deletion dramatically reduced extracellular protease activities and caused intracellular nutrient limitation when cultured on casein as the sole carbon source. PrtT was found to directly regulate the expression of an intracellular peptidase encoding gene (tripeptidyl-peptidase) and the gene encoding the extracellular dipeptidyl-aminopeptidase V, in addition to the expected extracellular peptidase genes (carboxypeptidase and aspergillopepsin). Five amylase genes (α-amylase, glucoamylase, α-glucosidase) and three major facilitator superfamily transporter genes related to maltose, monosaccharide and peptide transporting were also confirmed as putative targets of PrtT by EMSA. In contrast, the transcription levels of other genes encoding polysaccharide degrading enzymes (e.g. cellulases) and most iron or multidrug transporter encoding genes were up- or down-regulated in the ΔprtT mutant due to nutrient limitation resulting from the reduced usage of the sole carbon source, casein. These results deepen the understanding of the interaction of regulation systems for nitrogen and carbon catabolism, which benefit strain improvement of P. oxalicum for industrial enzyme production.
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Affiliation(s)
- Ling Chen
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Gen Zou
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Lei Zhang
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Ronald P de Vries
- Fungal Physiology Research Group, CBS-KNAW Fungal Biodiversity Centre, Uppsalalaan 8, 3584 CT, Utrecht, The Netherlands
| | - Xing Yan
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Jun Zhang
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Rui Liu
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Chengshu Wang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Yinbo Qu
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, Shandong 250100, China
| | - Zhihua Zhou
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
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Moore MM. The crucial role of iron uptake in Aspergillus fumigatus virulence. Curr Opin Microbiol 2013; 16:692-9. [DOI: 10.1016/j.mib.2013.07.012] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Revised: 07/16/2013] [Accepted: 07/16/2013] [Indexed: 02/01/2023]
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Kwon MJ, Jørgensen TR, Nitsche BM, Arentshorst M, Park J, Ram AFJ, Meyer V. The transcriptomic fingerprint of glucoamylase over-expression in Aspergillus niger. BMC Genomics 2012; 13:701. [PMID: 23237452 PMCID: PMC3554566 DOI: 10.1186/1471-2164-13-701] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Accepted: 12/06/2012] [Indexed: 12/11/2022] Open
Abstract
Background Filamentous fungi such as Aspergillus niger are well known for their exceptionally high capacity for secretion of proteins, organic acids, and secondary metabolites and they are therefore used in biotechnology as versatile microbial production platforms. However, system-wide insights into their metabolic and secretory capacities are sparse and rational strain improvement approaches are therefore limited. In order to gain a genome-wide view on the transcriptional regulation of the protein secretory pathway of A. niger, we investigated the transcriptome of A. niger when it was forced to overexpression the glaA gene (encoding glucoamylase, GlaA) and secrete GlaA to high level. Results An A. niger wild-type strain and a GlaA over-expressing strain, containing multiple copies of the glaA gene, were cultivated under maltose-limited chemostat conditions (specific growth rate 0.1 h-1). Elevated glaA mRNA and extracellular GlaA levels in the over-expressing strain were accompanied by elevated transcript levels from 772 genes and lowered transcript levels from 815 genes when compared to the wild-type strain. Using GO term enrichment analysis, four higher-order categories were identified in the up-regulated gene set: i) endoplasmic reticulum (ER) membrane translocation, ii) protein glycosylation, iii) vesicle transport, and iv) ion homeostasis. Among these, about 130 genes had predicted functions for the passage of proteins through the ER and those genes included target genes of the HacA transcription factor that mediates the unfolded protein response (UPR), e.g. bipA, clxA, prpA, tigA and pdiA. In order to identify those genes that are important for high-level secretion of proteins by A. niger, we compared the transcriptome of the GlaA overexpression strain of A. niger with six other relevant transcriptomes of A. niger. Overall, 40 genes were found to have either elevated (from 36 genes) or lowered (from 4 genes) transcript levels under all conditions that were examined, thus defining the core set of genes important for ensuring high protein traffic through the secretory pathway. Conclusion We have defined the A. niger genes that respond to elevated secretion of GlaA and, furthermore, we have defined a core set of genes that appear to be involved more generally in the intensified traffic of proteins through the secretory pathway of A. niger. The consistent up-regulation of a gene encoding the acetyl-coenzyme A transporter suggests a possible role for transient acetylation to ensure correct folding of secreted proteins.
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Affiliation(s)
- Min Jin Kwon
- Department Molecular Microbiology and Biotechnology, Institute of Biology Leiden, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
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Environmental responses and the control of iron homeostasis in fungal systems. Appl Microbiol Biotechnol 2012; 97:939-55. [DOI: 10.1007/s00253-012-4615-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2012] [Revised: 11/18/2012] [Accepted: 11/20/2012] [Indexed: 10/27/2022]
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