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Numazawa R, Tanaka Y, Nishioka S, Tsuji R, Maeda H, Tanaka M, Takeuchi M, Yamagata Y. Aspergillus oryzae PrtR alters transcription of individual peptidase genes in response to the growth environment. Appl Microbiol Biotechnol 2024; 108:90. [PMID: 38204127 PMCID: PMC10781853 DOI: 10.1007/s00253-023-12833-5] [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: 03/30/2023] [Revised: 09/19/2023] [Accepted: 09/30/2023] [Indexed: 01/12/2024]
Abstract
Aspergillus oryzae PrtR is an ortholog of the transcription factor PrtT, which positively regulates the transcription of extracellular peptidase genes in Aspergillus niger and Aspergillus fumigatus. To identify the genes under the control of PrtR and elucidate its regulatory mechanism in A. oryzae, prtR gene disruption mutants were generated. The control strain clearly showed a halo on media containing skim milk as the nitrogen source, whereas the ΔprtR strain formed a smaller halo. Measurement of acid peptidase activity revealed that approximately 84% of acidic endopeptidase and 86% of carboxypeptidase activities are positively regulated by PrtR. As the transcription of the prtR gene varied depending on culture conditions, especially with or without a protein substrate, it was considered that its transcription would be regulated in response to a nitrogen source. In addition, contrary to previous expectations, PrtR was found to act both in promoting and repressing the transcription of extracellular peptidase genes. The mode of regulation varied from gene to gene. Some genes were regulated in the same manner in both liquid and solid cultures, whereas others were regulated in different ways depending on the culture conditions. Furthermore, PrtR has been suggested to regulate the transcription of peptidase genes that are closely associated with other transcription factors. KEY POINTS: • Almost all peptidase genes in Aspergillus oryzae are positively regulated by PrtR • However, several genes are regulated negatively by PrtR • PrtR optimizes transcription of peptidase genes in response to culture conditions.
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Affiliation(s)
- Rika Numazawa
- Department of Applied Biological Science, United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-Cho, Fuchu, Tokyo, 1838509, Japan
| | - Yukako Tanaka
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-Cho, Fuchu, Tokyo, 1838509, Japan
| | - Sawako Nishioka
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-Cho, Fuchu, Tokyo, 1838509, Japan
| | - Ryotaro Tsuji
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-Cho, Fuchu, Tokyo, 1838509, Japan
| | - Hiroshi Maeda
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-Cho, Fuchu, Tokyo, 1838509, Japan
| | - Mizuki Tanaka
- Department of Applied Biological Science, United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-Cho, Fuchu, Tokyo, 1838509, Japan
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-Cho, Fuchu, Tokyo, 1838509, Japan
| | - Michio Takeuchi
- Department of Applied Biological Science, United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-Cho, Fuchu, Tokyo, 1838509, Japan
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-Cho, Fuchu, Tokyo, 1838509, Japan
| | - Youhei Yamagata
- Department of Applied Biological Science, United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-Cho, Fuchu, Tokyo, 1838509, Japan.
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-Cho, Fuchu, Tokyo, 1838509, Japan.
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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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Kelty MT, Miron-Ocampo A, Beattie SR. A series of pyrimidine-based antifungals with anti-mold activity disrupt ER function in Aspergillus fumigatus. Microbiol Spectr 2024; 12:e0104524. [PMID: 38916314 PMCID: PMC11302339 DOI: 10.1128/spectrum.01045-24] [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: 04/24/2024] [Accepted: 05/23/2024] [Indexed: 06/26/2024] Open
Abstract
Fungal infections are a major contributor to morbidity and mortality among immunocompromised populations. Moreover, fungal disease caused by molds are difficult to treat and are associated with particularly high mortality. To address the need for new mold-active antifungal drugs, we performed a high-throughput screen with Aspergillus fumigatus, the most common pathogenic mold. We identified a novel, pyrimidine-based chemical scaffold with broad-spectrum antifungal activity including activity against several difficult-to-treat molds. A chemical genetics screen of Saccharomyces cerevisiae suggested that this compound may target the endoplasmic reticulum (ER) and perturb ER function and/or homeostasis. Consistent with this model, this compound induces the unfolded protein response and inhibits secretion of A. fumigatus collagenases. Initial cytotoxicity and pharmacokinetic studies show favorable features including limited mammalian cell toxicity and bioavailability in vivo. Together, these data support the further medicinal chemistry and pre-clinical development of this pyrimidine scaffold toward more effective treatments for life-threatening invasive mold infections.IMPORTANCEInvasive fungal diseases are life-threatening infections caused by fungi in immunocompromised individuals. Currently, there are only three major classes of antifungal drugs available to treat fungal infections; however, these options are becoming even more limited with the global emergence of antifungal drug resistance. To address the need for new antifungal therapies, we performed a screen of chemical compounds and identified a novel molecule with antifungal activity. Initial characterization of this compound shows drug-like features and broad-spectrum activity against medically important fungi. Together, our results support the continued development of this compound as a potential future therapy for these devastating fungal infections.
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Affiliation(s)
- Martin T. Kelty
- Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Aracely Miron-Ocampo
- Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Sarah R. Beattie
- Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
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4
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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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Kamath MM, Lightfoot JD, Adams EM, Kiser RM, Wells BL, Fuller KK. The Aspergillus fumigatus UPR is variably activated across nutrient and host environments and is critical for the establishment of corneal infection. PLoS Pathog 2023; 19:e1011435. [PMID: 37906600 PMCID: PMC10637725 DOI: 10.1371/journal.ppat.1011435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 11/10/2023] [Accepted: 10/14/2023] [Indexed: 11/02/2023] Open
Abstract
The Aspergillus fumigatus unfolded protein response (UPR) is a two-component relay consisting of the ER-bound IreA protein, which splices and activates the mRNA of the transcription factor HacA. Spliced hacA accumulates under conditions of acute ER stress in vitro, and UPR null mutants are hypovirulent in a murine model of invasive pulmonary infection. In this report, we demonstrate that a hacA deletion mutant (ΔhacA) is furthermore avirulent in a model of fungal keratitis, a corneal infection, and an important cause of ocular morbidity and unilateral blindness worldwide. Interestingly, we demonstrate that A. fumigatus hacA is spliced in infected lung samples, but not in the cornea, suggesting the amount of ER stress experienced by the fungus varies upon the host niche. To better understand how the UPR contributes to fungal cell biology across a spectrum of ER-stress levels, we employed transcriptomics on the wild-type and ΔhacA strains in glucose minimal media (low stress), glucose minimal media with dithiothreitol (high stress), and gelatin minimal media as a proxy for the nutrient stress encountered in the cornea (mid-level stress). These data altogether reveal a unique HacA-dependent transcriptome under each condition, suggesting that HacA activity is finely-tuned and required for proper fungal adaptation in each environment. Taken together, our results indicate that the fungal UPR could serve as an important antifungal target in the setting of both invasive pulmonary and corneal infections.
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Affiliation(s)
- Manali M. Kamath
- Department of Microbiology & Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Jorge D. Lightfoot
- Department of Microbiology & Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Emily M. Adams
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Ryan M. Kiser
- Department of Pediatrics, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Becca L. Wells
- Department of Microbiology & Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Kevin K. Fuller
- Department of Microbiology & Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
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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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7
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Igarashi T, Katayama T, Maruyama JI. CRISPR/Cas9 genome editing for comparative genetic analysis related to soy sauce brewing in Aspergillus sojae industrial strains. Biosci Biotechnol Biochem 2023; 87:1236-1248. [PMID: 37500264 DOI: 10.1093/bbb/zbad101] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 07/11/2023] [Indexed: 07/29/2023]
Abstract
Aspergillus sojae has traditionally been used in soy sauce brewing. Genetic modification techniques have been established in A. sojae, but it is difficult to apply them to various industrial strains. Although we have previously developed a CRISPR/Cpf1 system for genetic modification of A. sojae, another genome editing system was required for versatile modification. In addition, repetitive genetic modification using the CRISPR system has not been established in A. sojae. In this study, we demonstrated mutagenesis, gene deletion/integration, and large deletion of a chromosomal region in A. sojae using the CRISPR/Cas9 system. We also successfully performed repetitive genetic modification using a method that involved forced recycling of genome-editing plasmids. Moreover, we demonstrated that the effects of genetic modification related to soy sauce brewing differed among A. sojae industrial strains. These results showed that our technique of using the CRISPR/Cas9 system is a powerful tool for genetic modification in A. sojae.
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Affiliation(s)
- Takayuki Igarashi
- Department of Biotechnology, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Takuya Katayama
- Department of Biotechnology, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Jun-Ichi Maruyama
- Department of Biotechnology, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
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8
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Li K, Zheng J, Yu L, Wang B, Pan L. Exploration of the Strategy for Improving the Expression of Heterologous Sweet Protein Monellin in Aspergillus niger. J Fungi (Basel) 2023; 9:jof9050528. [PMID: 37233239 DOI: 10.3390/jof9050528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 04/23/2023] [Accepted: 04/27/2023] [Indexed: 05/27/2023] Open
Abstract
Aspergillus niger is a primary cell factory for food-grade protein (enzyme) production due to its strong protein secretion capacity and unique safety characteristics. The bottleneck issue for the current A. niger expression system is the difference in expression yield of heterologous proteins of non-fungal origin compared to those of fungal origin, which is about three orders of magnitude. The sweet protein monellin, derived from West African plants, has the potential to become a food-grade sweetener due to its high sweetness and the benefit of not containing sugar itself, but it is extremely difficult to establish a research model for heterologous expression in A. niger, owing to extremely low expression, a small molecular weight, and being undetectable with conventional protein electrophoresis. HiBiT-Tag was fused with low-expressing monellin in this work to create a research model for heterologous protein expression in A. niger at ultra-low levels. We increased monellin expression by increasing the monellin copy number, fusing monellin with the endogenous highly expressed glycosylase glaA, and eliminating extracellular protease degradation, among other strategies. In addition, we investigated the effects of overexpression of molecular chaperones, inhibiting the ERAD pathway, and enhancing the synthesis of phosphatidylinositol, phosphatidylcholine, and diglycerides in the biomembrane system. Using medium optimization, we finally obtained 0.284 mg/L of monellin in the supernatant of the shake flask. This is the first time recombinant monellin has been expressed in A. niger, with the goal of investigating ways to improve the secretory expression of heterologous proteins at ultra-low levels, which can serve as a model for the expression of other heterologous proteins in A. niger.
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Affiliation(s)
- Ke Li
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou Higher Education Mega Center, Guangzhou 510006, China
| | - Junwei Zheng
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou Higher Education Mega Center, Guangzhou 510006, China
| | - Leyi Yu
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou Higher Education Mega Center, Guangzhou 510006, China
| | - Bin Wang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou Higher Education Mega Center, Guangzhou 510006, China
| | - Li Pan
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou Higher Education Mega Center, Guangzhou 510006, China
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Okaa UJ, Bertuzzi M, Fortune-Grant R, Thomson DD, Moyes DL, Naglik JR, Bignell E. Aspergillus fumigatus Drives Tissue Damage via Iterative Assaults upon Mucosal Integrity and Immune Homeostasis. Infect Immun 2023; 91:e0033322. [PMID: 36625602 PMCID: PMC9933693 DOI: 10.1128/iai.00333-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 10/21/2022] [Indexed: 01/11/2023] Open
Abstract
The human lung is constantly exposed to Aspergillus fumigatus spores, the most prevalent worldwide cause of fungal respiratory disease. Pulmonary tissue damage is a unifying feature of Aspergillus-related diseases; however, the mechanistic basis of damage is not understood. In the lungs of susceptible hosts, A. fumigatus undergoes an obligatory morphological switch involving spore germination and hyphal growth. We modeled A. fumigatus infection in cultured A549 human pneumocytes, capturing the phosphoactivation status of five host signaling pathways, nuclear translocation and DNA binding of eight host transcription factors, and expression of nine host response proteins over six time points encompassing exposures to live fungus and the secretome thereof. The resulting data set, comprised of more than 1,000 data points, reveals that pneumocytes mount differential responses to A. fumigatus spores, hyphae, and soluble secreted products via the NF-κB, JNK, and JNK + p38 pathways, respectively. Importantly, via selective degradation of host proinflammatory (IL-6 and IL-8) cytokines and growth factors (FGF-2), fungal secreted products reorchestrate the host response to fungal challenge as well as driving multiparameter epithelial damage, culminating in cytolysis. Dysregulation of NF-κB signaling, involving sequential stimulation of canonical and noncanonical signaling, was identified as a significant feature of host damage both in vitro and in a mouse model of invasive aspergillosis. Our data demonstrate that composite tissue damage results from iterative (repeated) exposures to different fungal morphotypes and secreted products and suggest that modulation of host responses to fungal challenge might represent a unified strategy for therapeutic control of pathologically distinct types of Aspergillus-related disease.
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Affiliation(s)
- Uju Joy Okaa
- Centre for Host-Microbiome Interactions, Faculty of Dentistry, Oral & Craniofacial Sciences, King’s College London, London, United Kingdom
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Margherita Bertuzzi
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Rachael Fortune-Grant
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Darren D. Thomson
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- MRC Centre for Medical Mycology, University of Exeter, Exeter, United Kingdom
| | - David L. Moyes
- Centre for Host-Microbiome Interactions, Faculty of Dentistry, Oral & Craniofacial Sciences, King’s College London, London, United Kingdom
| | - Julian R. Naglik
- Centre for Host-Microbiome Interactions, Faculty of Dentistry, Oral & Craniofacial Sciences, King’s College London, London, United Kingdom
| | - Elaine Bignell
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- MRC Centre for Medical Mycology, University of Exeter, Exeter, United Kingdom
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10
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Rahman S, van Rhijn N, Papastamoulis P, Thomson DD, Carter Z, Fortune-Grant R, Rattray M, Bromley MJ, Bignell E. Distinct Cohorts of Aspergillus fumigatus Transcription Factors Are Required for Epithelial Damage Occurring via Contact- or Soluble Effector-Mediated Mechanisms. Front Cell Infect Microbiol 2022; 12:907519. [PMID: 35982778 PMCID: PMC9379863 DOI: 10.3389/fcimb.2022.907519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 05/18/2022] [Indexed: 11/16/2022] Open
Abstract
Damage to the lung epithelium is a unifying feature of disease caused by the saprophytic fungus Aspergillus fumigatus. However, the mechanistic basis and the regulatory control of such damage is poorly characterized. Previous studies have identified A. fumigatus mediated pathogenesis as occurring at early (≤ 16 hours) or late (>16 hours) phases of the fungal interaction with epithelial cells, and respectively involve direct contact with the host cell or the action of soluble factors produced by mature fungal hyphae. Both early and late phases of epithelial damage have been shown to be subject to genetic regulation by the pH-responsive transcription factor PacC. This study sought to determine whether other transcriptional regulators play a role in modulating epithelial damage. In particular, whether the early and late phases of epithelial damage are governed by same or distinct regulators. Furthermore, whether processes such as spore uptake and hyphal adhesion, that have previously been documented to promote epithelial damage, are governed by the same cohorts of epithelial regulators. Using 479 strains from the recently constructed library of A. fumigatus transcription factor null mutants, two high-throughput screens assessing epithelial cell detachment and epithelial cell lysis were conducted. A total of 17 transcription factor mutants were found to exhibit reproducible deficits in epithelial damage causation. Of these, 10 mutants were defective in causing early phase damage via epithelial detachment and 8 mutants were defective in causing late phase damage via epithelial lysis. Remarkably only one transcription factor, PacC, was required for causation of both phases of epithelial damage. The 17 mutants exhibited varied and often unique phenotypic profiles with respect to fitness, epithelial adhesion, cell wall defects, and rates of spore uptake by epithelial cells. Strikingly, 9 out of 10 mutants deficient in causing early phase damage also exhibited reduced rates of hyphal extension, and culture supernatants of 7 out of 8 mutants deficient in late phase damage were significantly less cytotoxic. Our study delivers the first high-level overview of A. fumigatus regulatory genes governing lung epithelial damage, suggesting highly coordinated genetic orchestration of host-damaging activities that govern epithelial damage in both space and time.
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Affiliation(s)
- Sayema Rahman
- 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
| | | | - Darren D Thomson
- Manchester Fungal Infection Group, Division of Evolution, Infection and Genomics, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- MRC Centre for Medical Mycology, University of Exeter, Exeter, United Kingdom
| | - Zorana Carter
- Manchester Fungal Infection Group, Division of Evolution, Infection and Genomics, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Rachael Fortune-Grant
- Manchester Fungal Infection Group, Division of Evolution, Infection and Genomics, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Magnus Rattray
- Division of Informatics, School of Heath Sciences, University of Manchester, Manchester, United Kingdom
| | - Michael John Bromley
- Manchester Fungal Infection Group, Division of Evolution, Infection and Genomics, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Elaine Bignell
- Manchester Fungal Infection Group, Division of Evolution, Infection and Genomics, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- MRC Centre for Medical Mycology, University of Exeter, Exeter, United Kingdom
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11
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Tanaka M, Gomi K. Induction and Repression of Hydrolase Genes in Aspergillus oryzae. Front Microbiol 2021; 12:677603. [PMID: 34108952 PMCID: PMC8180590 DOI: 10.3389/fmicb.2021.677603] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 04/26/2021] [Indexed: 11/13/2022] Open
Abstract
The filamentous fungus Aspergillus oryzae, also known as yellow koji mold, produces high levels of hydrolases such as amylolytic and proteolytic enzymes. This property of producing large amounts of hydrolases is one of the reasons why A. oryzae has been used in the production of traditional Japanese fermented foods and beverages. A wide variety of hydrolases produced by A. oryzae have been used in the food industry. The expression of hydrolase genes is induced by the presence of certain substrates, and various transcription factors that regulate such expression have been identified. In contrast, in the presence of glucose, the expression of the glycosyl hydrolase gene is generally repressed by carbon catabolite repression (CCR), which is mediated by the transcription factor CreA and ubiquitination/deubiquitination factors. In this review, we present the current knowledge on the regulation of hydrolase gene expression, including CCR, in A. oryzae.
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Affiliation(s)
- Mizuki Tanaka
- Biomolecular Engineering Laboratory, School of Food and Nutritional Science, University of Shizuoka, Shizuoka, Japan
| | - Katsuya Gomi
- Laboratory of Fermentation Microbiology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
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12
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Ge LY, Liu J, Zheng HL, Mei H, Liang GZ, Liu WD. Comprehensive genome and transcriptome analysis of the dermatophyte Trichophyton schoenleinii reveals the candidate pathogenic genes. Mycoses 2021; 64:624-633. [PMID: 33586267 DOI: 10.1111/myc.13257] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 02/06/2021] [Accepted: 02/08/2021] [Indexed: 11/27/2022]
Abstract
BACKGROUND Trichophyton schoenleinii is an anthropophilic dermatophyte that causes tinea favosa. Nowadays, it remains an important pathogen in some regions of the world, mainly epidemic in Africa and West Asia. Despite the medical importance of T. schoenleinii infections, a high-quality reference genome for T. schoenleinii is still unavailable, neither its transcriptomic profile. OBJECTIVES The aim of the current study was to improve understanding of the underlying pathogenic mechanism of T. schoenleinii, and to define the candidate pathogenic genes of T. schoenleinii. METHODS Comprehensive genomic analysis of T. schoenleinii was carried out by Illumina and PacBio sequencing platforms. Transcriptome profiles of T. schoenleinii cultured in vitro in two media containing either keratin or soy protein were determined using RNA sequencing (RNA-seq) technology. RESULTS Here, we present the first draft genome sequence of T. schoenleinii strain T2s, which consists of 11 scaffolds containing 7474 predicted genes. Transcriptome analysis showed that genes involved in keratin hydrolysis have higher expression in T. schoenleinii grown in keratin medium, including genes encoding proteases, cysteine dioxygenase and acetamidase. Other genes with higher expression include genes encoding the components of the pH-responsive signal transduction pathways and transcription factors, many of which may play a role in pathogenicity. CONCLUSION In summary, this study provides new insights into the pathogenic mechanism of T. schoenleinii and highlights candidate genes for further development of novel targets in disease diagnosis and treatment of tinea favosa.
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Affiliation(s)
- Li-Yu Ge
- Department of Medical Mycology, Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing, China
| | - Jia Liu
- Department of Medical Mycology, Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing, China.,Department of Dermatology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Hai-Lin Zheng
- Department of Medical Mycology, Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing, China.,Jiangsu Key Laboratory of Molecular Biology for Skin Diseases and STIs, Nanjing, China
| | - Huan Mei
- Department of Medical Mycology, Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing, China.,Jiangsu Key Laboratory of Molecular Biology for Skin Diseases and STIs, Nanjing, China
| | - Guan-Zhao Liang
- Department of Medical Mycology, Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing, China.,Jiangsu Key Laboratory of Molecular Biology for Skin Diseases and STIs, Nanjing, China
| | - Wei-Da Liu
- Department of Medical Mycology, Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing, China.,Jiangsu Key Laboratory of Molecular Biology for Skin Diseases and STIs, Nanjing, China.,Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China
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13
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Rahman S, Thomson DD, Bertuzzi M. Automated Quantitative Analysis of Airway Epithelial Cell Detachment Upon Fungal Challenge. Methods Mol Biol 2021; 2260:225-239. [PMID: 33405042 DOI: 10.1007/978-1-0716-1182-1_16] [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] [Indexed: 03/23/2023]
Abstract
Host-pathogen interactions involve a complex interplay between host and pathogen factors, resulting in either host protective immunity or establishment of disease. One of the hallmarks for disease progression is host tissue destruction. The first host surface to interact with the opportunistic respiratory fungal pathogen, Aspergillus fumigatus, is the airway epithelium. Unravelling the mechanisms involved in airway epithelial cell damage by A. fumigatus is essential to understanding the establishment and progression of infection in the host. Although host cell damage can be measured in vitro by indirect cell lysis assays, here, we describe an automated, simple, and low-cost assay to directly visualize and quantify epithelial cell line damage after challenge with A. fumigatus. We employ the previously characterized tissue noninvasive A. fumigatus ΔpacC mutant to demonstrate the quantitative difference in cell damage relative to its parental tissue invasive strain. This assay is easily scaled up for high-throughput screening of multiple Aspergillus mutants and can be adapted to suit diverse host cell lines, different time points of infection, challenge with other microbes, and drugs or novel compounds.
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Affiliation(s)
- Sayema Rahman
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, Core Technology Facility, The University of Manchester, Manchester, UK.
| | - Darren D Thomson
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, Core Technology Facility, The University of Manchester, Manchester, UK
| | - Margherita Bertuzzi
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, Core Technology Facility Building, The University of Manchester, Manchester, UK
- Lydia Becker Institute of Immunology and Inflammation, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK
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14
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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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15
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Role of Amino Acid Metabolism in the Virulence of Human Pathogenic Fungi. CURRENT CLINICAL MICROBIOLOGY REPORTS 2019. [DOI: 10.1007/s40588-019-00124-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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16
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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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17
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Gomi K. Regulatory mechanisms for amylolytic gene expression in the koji mold Aspergillus oryzae. Biosci Biotechnol Biochem 2019; 83:1385-1401. [PMID: 31159661 DOI: 10.1080/09168451.2019.1625265] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The koji mold Aspergillus oryzae has been used in traditional Japanese food and beverage fermentation for over a thousand years. Amylolytic enzymes are important in sake fermentation, wherein production is induced by starch or malto-oligosaccharides. This inducible production requires at least two transcription activators, AmyR and MalR. Among amylolytic enzymes, glucoamylase GlaB is produced exclusively in solid-state culture and plays a critical role in sake fermentation owing to its contribution to glucose generation from starch. A recent study demonstrated that glaB gene expression is regulated by a novel transcription factor, FlbC, in addition to AmyR in solid-state culture. Amylolytic enzyme production is generally repressed by glucose due to carbon catabolite repression (CCR), which is mediated by the transcription factor CreA. Modifying CCR machinery, including CreA, can improve amylolytic enzyme production. This review focuses on the role of transcription factors in regulating A. oryzae amylolytic gene expression.
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Affiliation(s)
- Katsuya Gomi
- a Laboratory of Fermentation Microbiology, Graduate School of Agricultural Science , Tohoku University , Sendai , Japan
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18
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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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19
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Shende R, Wong SSW, Rapole S, Beau R, Ibrahim-Granet O, Monod M, Gührs KH, Pal JK, Latgé JP, Madan T, Aimanianda V, Sahu A. Aspergillus fumigatus conidial metalloprotease Mep1p cleaves host complement proteins. J Biol Chem 2018; 293:15538-15555. [PMID: 30139746 PMCID: PMC6177592 DOI: 10.1074/jbc.ra117.001476] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 08/02/2018] [Indexed: 12/30/2022] Open
Abstract
Innate immunity in animals including humans encompasses the complement system, which is considered an important host defense mechanism against Aspergillus fumigatus, one of the most ubiquitous opportunistic human fungal pathogens. Previously, it has been shown that the alkaline protease Alp1p secreted from A. fumigatus mycelia degrades the complement components C3, C4, and C5. However, it remains unclear how the fungal spores (i.e. conidia) defend themselves against the activities of the complement system immediately after inhalation into the lung. Here, we show that A. fumigatus conidia contain a metalloprotease Mep1p, which is released upon conidial contact with collagen and inactivates all three complement pathways. In particular, Mep1p efficiently inactivated the major complement components C3, C4, and C5 and their activation products (C3a, C4a, and C5a) as well as the pattern-recognition molecules MBL and ficolin-1, either by directly cleaving them or by cleaving them to a form that is further broken down by other proteases of the complement system. Moreover, incubation of Mep1p with human serum significantly inhibited the complement hemolytic activity and conidial opsonization by C3b and their subsequent phagocytosis by macrophages. Together, these results indicate that Mep1p associated with and released from A. fumigatus conidia likely facilitates early immune evasion by disarming the complement defense in the human host.
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Affiliation(s)
- Rajashri Shende
- From the Complement Biology Laboratory and
- the Dr. D. Y. Patil Biotechnology and Bioinformatics Institute, Dr. D. Y. Patil Vidyapeeth, Tathawade, Pune-411033, India
| | | | - Srikanth Rapole
- Proteomics Laboratory, National Centre for Cell Science, S. P. Pune University Campus, Ganeshkhind, Pune-411007, India
| | | | | | - Michel Monod
- the Service de Dermatologie, Laboratoire de Mycologie, Centre Hospitalier Universitaire Vaudois, 1011 Lausanne, Switzerland
| | - Karl-Heinz Gührs
- the Leibniz Institute on Aging-Fritz Lipmann Institute, Jena-07745, Germany, and
| | - Jayanta Kumar Pal
- the Dr. D. Y. Patil Biotechnology and Bioinformatics Institute, Dr. D. Y. Patil Vidyapeeth, Tathawade, Pune-411033, India
| | | | - Taruna Madan
- the ICMR-National Institute for Research in Reproductive Health, Parel, Mumbai-400012, India
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20
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Role of the small GTPase Rho1 in cell wall integrity, stress response, and pathogenesis of Aspergillus fumigatus. Fungal Genet Biol 2018; 120:30-41. [PMID: 30205199 DOI: 10.1016/j.fgb.2018.09.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 09/04/2018] [Accepted: 09/08/2018] [Indexed: 11/24/2022]
Abstract
Aspergillus fumigatus is a major pathogen of invasive pulmonary aspergillosis. The small GTPase, Rho1, of A. fumigatus is reported to comprise a potential regulatory subunit of β-1,3-glucan synthase and is indispensable for fungal viability; however, the role of AfRho1 on the growth, cell wall integrity, and pathogenesis of A. fumigatus is still poorly understood. We constructed A. fumigatus mutants with conditional- and overexpression of Rho1 and found that defects of AfRho1 expression led to the reduction of β-1,3-glucan and glucosamine moieties on the cell wall, with down-regulated transcription of genes in the cell wall integrity signaling pathway and a decrease of calcofluor white (CFW)-stimulated mitogen-activated protein kinase (MpkA) phosphorylation and cytoplasmic leakage compared to those of the wild-type strain (WT). In addition, down-regulation of AfRho1 expression caused much higher sensitivity of A. fumigatus to H2O2 and alkaline pH compared to that of WT. Decrease of AfRho1 expression also attenuated the A. fumigatus pathogenicity in Galleria mellonella and inhibited conidial internalization into lung epithelial cells and inflammatory factor release. In contrast, overexpression of Rho1 did not alter A. fumigatus morphology, susceptibility to cell wall stresses, or pathogenicity relative to its parental strain. Taken together, our findings support AfRho1 as an essential regulator of the cell wall integrity, stress response, and pathogenesis of A. fumigatus.
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21
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Zhang C, Liu X, Chen F, Hu Y, Li Z, Liu Y, Han X, Sun Y, Han L. Gliotoxin destructs the pulmonary epithelium barrier function by reducing cofilin oligomer formation to promote the dissolution of actin stress fibers. Microb Pathog 2018; 123:169-176. [PMID: 30017941 DOI: 10.1016/j.micpath.2018.07.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 07/10/2018] [Accepted: 07/10/2018] [Indexed: 01/01/2023]
Abstract
The destruction of pulmonary epithelium is a major feature of lung diseases caused by the fungal pathogen Aspergillus fumigatus (A. fumigatus). Gliotoxin, a major mycotoxin of A. fumigatus, is widely postulated to be associated with the tissue invasion. However, the mechanism is unclear. In this study, we first discovered that cofilin, a regulator of actin dynamics in the pulmonary epithelial cells, existed mainly in the form of oligomer, which kept it unable to depolymerize actin filaments. Gliotoxin could reduce the formation of cofilin oligomer and promote the release of active cofilin monomer by regulating cofilin phosphorylation balance. Then, the active cofilin induced the dissolution of actin stress fibers to result in the disruption of pulmonary epithelium barrier function. Collectively, our study revealed a novel mechanism of gliotoxin destructing lung epithelium barrier function and for the first time indicated the role of cofilin oligomer in this process.
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Affiliation(s)
- Changjian Zhang
- Academy of Military Medical Sciences, Academy of Military Sciences, PLA, Beijing, China; Institute for Disease Control and Prevention of PLA, Beijing, China
| | - Xiaoyu Liu
- Academy of Military Medical Sciences, Academy of Military Sciences, PLA, Beijing, China; Institute for Disease Control and Prevention of PLA, Beijing, China
| | - Fangyan Chen
- Institute for Disease Control and Prevention of PLA, Beijing, China
| | - Yingsong Hu
- Institute for Disease Control and Prevention of PLA, Beijing, China
| | - Zhiqian Li
- Academy of Military Medical Sciences, Academy of Military Sciences, PLA, Beijing, China; Institute for Disease Control and Prevention of PLA, Beijing, China
| | - Yanxi Liu
- Institute for Disease Control and Prevention of PLA, Beijing, China
| | - Xuelin Han
- Institute for Disease Control and Prevention of PLA, Beijing, China
| | - Yansong Sun
- Academy of Military Medical Sciences, Academy of Military Sciences, PLA, Beijing, China.
| | - Li Han
- Institute for Disease Control and Prevention of PLA, Beijing, China.
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22
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Fernandes J, Hamidi F, Leborgne R, Beau R, Castier Y, Mordant P, Boukkerou A, Latgé JP, Pretolani M. Penetration of the Human Pulmonary Epithelium by Aspergillus fumigatus Hyphae. J Infect Dis 2018; 218:1306-1313. [DOI: 10.1093/infdis/jiy298] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 05/23/2018] [Indexed: 12/12/2022] Open
Affiliation(s)
- Julien Fernandes
- INSERM UMR1152, Physiopathologie et Epidémiologie des Maladies Respiratoires, Paris, France
- Université Paris Diderot, Sorbonne Paris-Cité, Faculté de Médecine, site Bichat, France
- Laboratory of Excellence INFLAMEX, Université Sorbonne Paris-Cité, France
- Département Hospitalo-Universitaire FIRE, Paris, France
| | - Fatima Hamidi
- INSERM UMR1152, Physiopathologie et Epidémiologie des Maladies Respiratoires, Paris, France
- Université Paris Diderot, Sorbonne Paris-Cité, Faculté de Médecine, site Bichat, France
- Laboratory of Excellence INFLAMEX, Université Sorbonne Paris-Cité, France
- Département Hospitalo-Universitaire FIRE, Paris, France
| | - Remi Leborgne
- ImagoSeine Electron Microscopy Facility, Institut Jacques Monod, Centre National de la Recherche Scientifique UMR 7592, Université Paris Diderot, Sorbonne Paris-Cité, France
| | - Remi Beau
- Unité des Aspergillus, Institut Pasteur, Paris, France
| | - Yves Castier
- INSERM UMR1152, Physiopathologie et Epidémiologie des Maladies Respiratoires, Paris, France
- Université Paris Diderot, Sorbonne Paris-Cité, Faculté de Médecine, site Bichat, France
- Laboratory of Excellence INFLAMEX, Université Sorbonne Paris-Cité, France
- Département Hospitalo-Universitaire FIRE, Paris, France
- Service de Chirurgie Thoracique, Groupement Hospitalier Universitaire Nord Bichat-Claude Bernard, Assistance Publique des Hopitaux de Paris, France
| | - Pierre Mordant
- INSERM UMR1152, Physiopathologie et Epidémiologie des Maladies Respiratoires, Paris, France
- Université Paris Diderot, Sorbonne Paris-Cité, Faculté de Médecine, site Bichat, France
- Laboratory of Excellence INFLAMEX, Université Sorbonne Paris-Cité, France
- Département Hospitalo-Universitaire FIRE, Paris, France
- Service de Chirurgie Thoracique, Groupement Hospitalier Universitaire Nord Bichat-Claude Bernard, Assistance Publique des Hopitaux de Paris, France
| | - Amira Boukkerou
- INSERM UMR1152, Physiopathologie et Epidémiologie des Maladies Respiratoires, Paris, France
- Université Paris Diderot, Sorbonne Paris-Cité, Faculté de Médecine, site Bichat, France
- Laboratory of Excellence INFLAMEX, Université Sorbonne Paris-Cité, France
- Département Hospitalo-Universitaire FIRE, Paris, France
| | | | - Marina Pretolani
- INSERM UMR1152, Physiopathologie et Epidémiologie des Maladies Respiratoires, Paris, France
- Université Paris Diderot, Sorbonne Paris-Cité, Faculté de Médecine, site Bichat, France
- Laboratory of Excellence INFLAMEX, Université Sorbonne Paris-Cité, France
- Département Hospitalo-Universitaire FIRE, Paris, France
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23
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Ries LNA, Beattie S, Cramer RA, Goldman GH. Overview of carbon and nitrogen catabolite metabolism in the virulence of human pathogenic fungi. Mol Microbiol 2017; 107:277-297. [PMID: 29197127 DOI: 10.1111/mmi.13887] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 11/20/2017] [Accepted: 11/23/2017] [Indexed: 12/12/2022]
Abstract
It is estimated that fungal infections, caused most commonly by Candida albicans, Aspergillus fumigatus and Cryptococcus neoformans, result in more deaths annually than malaria or tuberculosis. It has long been hypothesized the fungal metabolism plays a critical role in virulence though specific nutrient sources utilized by human pathogenic fungi in vivo has remained enigmatic. However, the metabolic utilisation of preferred carbon and nitrogen sources, encountered in a host niche-dependent manner, is known as carbon catabolite and nitrogen catabolite repression (CCR, NCR), and has been shown to be important for virulence. Several sensory and uptake systems exist, including carbon and nitrogen source-specific sensors and transporters, that allow scavenging of preferred nutrient sources. Subsequent metabolic utilisation is governed by transcription factors, whose functions and essentiality differ between fungal species. Furthermore, additional factors exist that contribute to the implementation of CCR and NCR. The role of the CCR and NCR-related factors in virulence varies greatly between fungal species and a substantial gap in knowledge exists regarding specific pathways. Further elucidation of carbon and nitrogen metabolism mechanisms is therefore required in a fungal species- and animal model-specific manner in order to screen for targets that are potential candidates for anti-fungal drug development.
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Affiliation(s)
- Laure Nicolas Annick Ries
- Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes, Ribeirão Preto, São Paulo, 3900, CEP 14049-900, Brazil
| | - Sarah Beattie
- Department of Microbiology & Immunology, Geisel School of Medicine at Dartmouth, 74 College Street Remsen 213, Hanover, NH 03755, USA
| | - Robert A Cramer
- Department of Microbiology & Immunology, Geisel School of Medicine at Dartmouth, 74 College Street Remsen 213, Hanover, NH 03755, USA
| | - Gustavo H Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Avenida do Café s/n°, Ribeirão Preto, São Paulo, CEP 14040903, Brazil
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24
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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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25
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Kamaruddin N, Storms R, Mahadi NM, Illias RM, Bakar FDA, Murad AMA. Reduction of Extracellular Proteases Increased Activity and Stability of Heterologous Protein in $${ Aspergillus}$$ A s p e r g i l l u s $${ niger}$$ n i g e r. ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING 2017. [DOI: 10.1007/s13369-017-2914-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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26
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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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27
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Krappmann S. How to invade a susceptible host: cellular aspects of aspergillosis. Curr Opin Microbiol 2016; 34:136-146. [PMID: 27816786 DOI: 10.1016/j.mib.2016.10.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Revised: 10/12/2016] [Accepted: 10/17/2016] [Indexed: 02/07/2023]
Abstract
Diseases caused by Aspergillus spp. and in particular A. fumigatus are manifold and affect individuals suffering from immune dysfunctions, among them immunocompromised ones. The determinants of whether the encounter of a susceptible host with infectious propagules of this filamentous saprobe results in infection have been characterized to a limited extent. Several cellular characteristics of A. fumigatus that have evolved in its natural environment contribute to its virulence, among them general traits as well as particular ones that affect interaction with the mammalian host. Among the latter, conidial constituents, cell wall components, secreted proteins as well as extrolites shape the tight interaction of A. fumigatus with the host milieu and also contribute to evasion from immune surveillance.
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Affiliation(s)
- Sven Krappmann
- Institute of Microbiology - Clinical Microbiology, Immunology and Hygiene, University Hospital Erlangen and Friedrich-Alexander University Erlangen-Nürnberg, Wasserturmstr. 3/5, D-91054 Erlangen, Germany.
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28
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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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29
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Caffrey AK, Obar JJ. Alarmin(g) the innate immune system to invasive fungal infections. Curr Opin Microbiol 2016; 32:135-143. [PMID: 27351354 DOI: 10.1016/j.mib.2016.06.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 05/04/2016] [Accepted: 06/07/2016] [Indexed: 11/24/2022]
Abstract
Fungi encounter numerous stresses in a mammalian host, including the immune system, which they must adapt to in order to grow and cause disease. The host immune system tunes its response to the threat level posed by the invading pathogen. We discuss recent findings on how interleukin (IL)-1 signaling is central to tuning the immune response to the virulence potential of invasive fungi, as well as other pathogens. Moreover, we discuss fungal factors that may drive tissue invasion and destruction that regulate IL-1 cytokine release. Moving forward understanding the mechanisms of fungal adaption to the host, together with understanding how the host innate immune system recognizes invading fungal pathogens will increase our therapeutic options for treatment of invasive fungal infections.
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Affiliation(s)
- Alayna K Caffrey
- Montana State University, Department of Microbiology & Immunology, Bozeman, MT 59718, United States; Geisel School of Medicine at Dartmouth, Department of Microbiology & Immunology, Lebanon, NH 03756, United States
| | - Joshua J Obar
- Geisel School of Medicine at Dartmouth, Department of Microbiology & Immunology, Lebanon, NH 03756, United States.
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30
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Exploration of Sulfur Assimilation of Aspergillus fumigatus Reveals Biosynthesis of Sulfur-Containing Amino Acids as a Virulence Determinant. Infect Immun 2016; 84:917-929. [PMID: 26787716 DOI: 10.1128/iai.01124-15] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 01/07/2016] [Indexed: 12/17/2022] Open
Abstract
Fungal infections are of major relevance due to the increased numbers of immunocompromised patients, frequently delayed diagnosis, and limited therapeutics. To date, the growth and nutritional requirements of fungi during infection, which are relevant for invasion of the host, are poorly understood. This is particularly true for invasive pulmonary aspergillosis, as so far, sources of (macro)elements that are exploited during infection have been identified to only a limited extent. Here, we have investigated sulfur (S) utilization by the human-pathogenic mold Aspergillus fumigatus during invasive growth. Our data reveal that inorganic S compounds or taurine is unlikely to serve as an S source during invasive pulmonary aspergillosis since a sulfate transporter mutant strain and a sulfite reductase mutant strain are fully virulent. In contrast, the S-containing amino acid cysteine is limiting for fungal growth, as proven by the reduced virulence of a cysteine auxotroph. Moreover, phenotypic characterization of this strain further revealed the robustness of the subordinate glutathione redox system. Interestingly, we demonstrate that methionine synthase is essential for A. fumigatus virulence, defining the biosynthetic route of this proteinogenic amino acid as a potential antifungal target. In conclusion, we provide novel insights into the nutritional requirements ofA. fumigatus during pathogenesis, a prerequisite to understanding and fighting infection.
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31
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Halperin A, Shadkchan Y, Pisarevsky E, Szpilman AM, Sandovsky H, Osherov N, Benhar I. Novel Water-Soluble Amphotericin B-PEG Conjugates with Low Toxicity and Potent in Vivo Efficacy. J Med Chem 2016; 59:1197-206. [DOI: 10.1021/acs.jmedchem.5b01862] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | - Evgeni Pisarevsky
- Schulich
Faculty of Chemistry, Israel Institute of Technology, 3200008 Technion-City, Haifa, Israel
| | - Alex M. Szpilman
- Schulich
Faculty of Chemistry, Israel Institute of Technology, 3200008 Technion-City, Haifa, Israel
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32
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Funk J, Schaarschmidt B, Slesiona S, Hallström T, Horn U, Brock M. The glycolytic enzyme enolase represents a plasminogen-binding protein on the surface of a wide variety of medically important fungal species. Int J Med Microbiol 2015; 306:59-68. [PMID: 26679571 DOI: 10.1016/j.ijmm.2015.11.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 10/27/2015] [Accepted: 11/29/2015] [Indexed: 11/26/2022] Open
Abstract
Allergies are an increasing issue in human health and can, eventually, cause severe anaphylactic shock. Aspergillus fumigatus and Candida albicans are leading causes of life-threatening invasive fungal infections in immunocompromised patients, but can also cause severe allergic responses in otherwise healthy individuals. The glycolytic enzyme enolase is known as a major allergen despite its function in intracellular metabolism. Therefore, its presentation on surfaces of different fungal species was investigated by using antibodies raised against recombinant enolases from A. fumigatus and C. albicans. Examination of antibody specificity revealed cross-reactivity to cell-free extracts from Aspergillus terreus, Aspergillus flavus, Aspergillus nidulans and Candida glabrata, but not against any of the three human enolases. Antibody specificity was further confirmed by hybridization with other recombinant fungal enolases, where the antibodies recognized different subsets of fungal enolases. When surface presentation of enolase was tested on intact fungal cells, a positive staining was obtained with those antibodies that also recognized the enzyme from the respective cell-free extract. This implies a general surface presentation of this glycolytic enzyme among fungal species and provides hints for its predominant recognition as an allergen. Additionally, A. fumigatus and C. albicans enolase bound to human plasminogen, which remained accessible for the plasminogen activator uPA. This implies a potential role of enolase in the invasion and dissemination process during fungal infections.
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Affiliation(s)
- Jana Funk
- Bio Pilot Plant, Leibniz-Institute for Natural Product Research and Infection Biology-Hans-Knöll-Institute (HKI), Beutenbergstr. 11a, 07745, Jena, Germany
| | - Barbara Schaarschmidt
- Bio Pilot Plant, Leibniz-Institute for Natural Product Research and Infection Biology-Hans-Knöll-Institute (HKI), Beutenbergstr. 11a, 07745, Jena, Germany
| | - Silvia Slesiona
- Microbial Immunology, Leibniz-Institute for Natural Product Research and Infection Biology-Hans-Knöll-Institute (HKI), Beutenbergstr. 11a, 07745, Jena, Germany
| | - Teresia Hallström
- Infection Biology, Leibniz-Institute for Natural Product Research and Infection Biology-Hans-Knöll-Institute (HKI), Beutenbergstr. 11a, 07745, Jena, Germany
| | - Uwe Horn
- Bio Pilot Plant, Leibniz-Institute for Natural Product Research and Infection Biology-Hans-Knöll-Institute (HKI), Beutenbergstr. 11a, 07745, Jena, Germany
| | - Matthias Brock
- Microbial Biochemistry and Physiology, Leibniz-Institute for Natural Product Research and Infection Biology-Hans-Knöll-Institute (HKI), Beutenbergstr. 11a, 07745, Jena, Germany; Institute for Microbiology, Friedrich-Schiller-University Jena, 07743, Jena, Germany; Fungal Genetics and Biology Group, School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
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33
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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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34
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Selvam RM, Nithya R, Devi PN, Shree RSB, Nila MV, Demonte NL, Thangavel C, Maheshwari JJ, Lalitha P, Prajna NV, Dharmalingam K. Exoproteome of Aspergillus flavus corneal isolates and saprophytes: identification of proteoforms of an oversecreted alkaline protease. J Proteomics 2014; 115:23-35. [PMID: 25497218 DOI: 10.1016/j.jprot.2014.11.017] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Revised: 11/19/2014] [Accepted: 11/28/2014] [Indexed: 01/14/2023]
Abstract
UNLABELLED Aspergillus flavus infects the human eye leading to keratitis. Extracellular proteins, the earliest proteins that come in contact with the host and virulence related exoproteins, were identified in the fungus isolated from infected cornea. Virulence of the corneal isolates was tested in the Galleria mellonella larvae model and those isolates showing higher virulence were taken for subsequent exoproteome analysis. High resolution two-dimensional electrophoresis and mass spectrometry were used to generate A. flavus exoproteome reference map as well as to profile most of the exoproteins. Analysis of the identified proteins clearly shows the major biological processes that they are involved in. Nearly 50% of the exoproteins possess catalytic activity and one of these, an alkaline serine protease (Alp1) is present in high abundance as well as multiple proteoforms. Many proteins in the A. flavus exoproteome have been shown to be virulence factors in other pathogens indicating the probable role for these proteins in the corneal infection as well. Interestingly, the majority of the exoproteins do not have secretory signal indicating that they are secreted through the non-classical pathway. Thus, this study provides a clue to the early strategies employed by the pathogen to establish an infection in an immunocompetent host. BIOLOGICAL SIGNIFICANCE The outcome of a fungal infection in an immunocompetent human eye depends on the ability of the fungus to overcome the host defense and propagate itself. In this process, the earliest events with respect to the fungal proteins involved include the secretory proteins of the invading organism. As a first step towards understanding the role of the extracellular proteins, exoproteome profile of the fungal isolates was generated. The fungal isolates from cornea showed a distinct pattern of the exoproteome when compared to the saprophyte. Since corneal isolates also showed higher virulence in the insect larval model, presumably the proteins elaborated by the corneal isolates are virulence related. One of the abundant proteins is an alkaline serine protease and this protein exists as multiple proteoforms. This study reports the comprehensive profile of exoproteome and reveals proteins that are potential virulence factors.
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Affiliation(s)
- Ramu Muthu Selvam
- Proteomics Department, Aravind Medical Research Foundation, Dr. G. Venkataswamy Eye Research Institute, Aravind Eye Care System, Madurai, Tamil Nadu, India
| | - Rathnavel Nithya
- Proteomics Department, Aravind Medical Research Foundation, Dr. G. Venkataswamy Eye Research Institute, Aravind Eye Care System, Madurai, Tamil Nadu, India
| | - Palraj Narmatha Devi
- Proteomics Department, Aravind Medical Research Foundation, Dr. G. Venkataswamy Eye Research Institute, Aravind Eye Care System, Madurai, Tamil Nadu, India
| | - R S Bhuvana Shree
- Proteomics Department, Aravind Medical Research Foundation, Dr. G. Venkataswamy Eye Research Institute, Aravind Eye Care System, Madurai, Tamil Nadu, India
| | - Murugesan Valar Nila
- Proteomics Department, Aravind Medical Research Foundation, Dr. G. Venkataswamy Eye Research Institute, Aravind Eye Care System, Madurai, Tamil Nadu, India
| | - Naveen Luke Demonte
- Proteomics Department, Aravind Medical Research Foundation, Dr. G. Venkataswamy Eye Research Institute, Aravind Eye Care System, Madurai, Tamil Nadu, India
| | - Chitra Thangavel
- Proteomics Department, Aravind Medical Research Foundation, Dr. G. Venkataswamy Eye Research Institute, Aravind Eye Care System, Madurai, Tamil Nadu, India
| | - Jayapal Jeya Maheshwari
- Proteomics Department, Aravind Medical Research Foundation, Dr. G. Venkataswamy Eye Research Institute, Aravind Eye Care System, Madurai, Tamil Nadu, India
| | - Prajna Lalitha
- Department Of Ocular Microbiology, Aravind Eye Hospital, Aravind Eye Care System, Madurai, Tamil Nadu, India
| | | | - Kuppamuthu Dharmalingam
- Proteomics Department, Aravind Medical Research Foundation, Dr. G. Venkataswamy Eye Research Institute, Aravind Eye Care System, Madurai, Tamil Nadu, India.
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35
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The pH-responsive PacC transcription factor of Aspergillus fumigatus governs epithelial entry and tissue invasion during pulmonary aspergillosis. PLoS Pathog 2014; 10:e1004413. [PMID: 25329394 PMCID: PMC4199764 DOI: 10.1371/journal.ppat.1004413] [Citation(s) in RCA: 112] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 08/20/2014] [Indexed: 12/29/2022] Open
Abstract
Destruction of the pulmonary epithelium is a major feature of lung diseases caused by the mould pathogen Aspergillus fumigatus. Although it is widely postulated that tissue invasion is governed by fungal proteases, A. fumigatus mutants lacking individual or multiple enzymes remain fully invasive, suggesting a concomitant requirement for other pathogenic activities during host invasion. In this study we discovered, and exploited, a novel, tissue non-invasive, phenotype in A. fumigatus mutants lacking the pH-responsive transcription factor PacC. Our study revealed a novel mode of epithelial entry, occurring in a cell wall-dependent manner prior to protease production, and via the Dectin-1 β-glucan receptor. ΔpacC mutants are defective in both contact-mediated epithelial entry and protease expression, and significantly attenuated for pathogenicity in leukopenic mice. We combined murine infection modelling, in vivo transcriptomics, and in vitro infections of human alveolar epithelia, to delineate two major, and sequentially acting, PacC-dependent processes impacting epithelial integrity in vitro and tissue invasion in the whole animal. We demonstrate that A. fumigatus spores and germlings are internalised by epithelial cells in a contact-, actin-, cell wall- and Dectin-1 dependent manner and ΔpacC mutants, which aberrantly remodel the cell wall during germinative growth, are unable to gain entry into epithelial cells, both in vitro and in vivo. We further show that PacC acts as a global transcriptional regulator of secreted molecules during growth in the leukopenic mammalian lung, and profile the full cohort of secreted gene products expressed during invasive infection. Our study reveals a combinatorial mode of tissue entry dependent upon sequential, and mechanistically distinct, perturbations of the pulmonary epithelium and demonstrates, for the first time a protective role for Dectin-1 blockade in epithelial defences. Infecting ΔpacC mutants are hypersensitive to cell wall-active antifungal agents highlighting the value of PacC signalling as a target for antifungal therapy. Inhaled spores of the pathogenic mould Aspergillus fumigatus cause fungal lung infections in humans having immune defects. A. fumigatus spores germinate within the immunocompromised lung, producing invasively growing, elongated cells called hyphae. Hyphae degrade the surrounding pulmonary tissue, a process thought to be caused by secreted fungal enzymes; however, A. fumigatus mutants lacking one or more protease activities retain fully invasive phenotypes in mouse models of disease. Here we report the first discovery of a non-invasive A. fumigatus mutant, which lacks a pH-responsive transcription factor PacC. Using global transcriptional profiling of wild type and mutant isolates, and in vitro pulmonary invasion assays, we established that loss of PacC leads to a compound non-invasive phenotype characterised by deficits in both contact-mediated epithelial entry and protease expression. Consistent with an important role for epithelial entry in promoting invasive disease in mammalian tissues, PacC mutants remain surface-localised on mammalian epithelia, both in vitro and in vivo. Our study sets a new precedent for involvement of both host and pathogen activities in promoting epithelial invasion by A. fumigatus and supports a model wherein fungal protease activity acting subsequently to, or in parallel with, host-mediated epithelial entry provides the mechanistic basis for tissue invasion.
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36
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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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Huang W, Shang Y, Chen P, Gao Q, Wang C. MrpacC regulates sporulation, insect cuticle penetration and immune evasion inMetarhizium robertsii. Environ Microbiol 2014; 17:994-1008. [DOI: 10.1111/1462-2920.12451] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Accepted: 01/30/2014] [Indexed: 01/04/2023]
Affiliation(s)
- Wei Huang
- 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
| | - Yanfang Shang
- 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
| | - Peilin Chen
- 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
| | - Qiang Gao
- 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
| | - 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
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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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Regulation of sulphur assimilation is essential for virulence and affects iron homeostasis of the human-pathogenic mould Aspergillus fumigatus. PLoS Pathog 2013; 9:e1003573. [PMID: 24009505 PMCID: PMC3757043 DOI: 10.1371/journal.ppat.1003573] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Accepted: 07/08/2013] [Indexed: 11/19/2022] Open
Abstract
Sulphur is an essential element that all pathogens have to absorb from their surroundings in order to grow inside their infected host. Despite its importance, the relevance of sulphur assimilation in fungal virulence is largely unexplored. Here we report a role of the bZIP transcription factor MetR in sulphur assimilation and virulence of the human pathogen Aspergillus fumigatus. The MetR regulator is essential for growth on a variety of sulphur sources; remarkably, it is fundamental for assimilation of inorganic S-sources but dispensable for utilization of methionine. Accordingly, it strongly supports expression of genes directly related to inorganic sulphur assimilation but not of genes connected to methionine metabolism. On a broader scale, MetR orchestrates the comprehensive transcriptional adaptation to sulphur-starving conditions as demonstrated by digital gene expression analysis. Surprisingly, A. fumigatus is able to utilize volatile sulphur compounds produced by its methionine catabolism, a process that has not been described before and that is MetR-dependent. The A. fumigatus MetR transcriptional activator is important for virulence in both leukopenic mice and an alternative mini-host model of aspergillosis, as it was essential for the development of pulmonary aspergillosis and supported the systemic dissemination of the fungus. MetR action under sulphur-starving conditions is further required for proper iron regulation, which links regulation of sulphur metabolism to iron homeostasis and demonstrates an unprecedented regulatory crosstalk. Taken together, this study provides evidence that regulation of sulphur assimilation is not only crucial for A. fumigatus virulence but also affects the balance of iron in this prime opportunistic pathogen.
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Abstract
Hemolysins are a class of proteins defined by their ability to lyse red cells but have been described to exhibit pleiotropic functions. These proteins have been extensively studied in bacteria and more recently in fungi. Within the last decade, a number of studies have characterized fungal hemolysins and revealed a fascinating yet diverse group of proteins. The purpose of this review is to provide a synopsis of the known fungal hemolysins with an emphasis on those belonging to the aegerolysin protein family. New insight and perspective into fungal hemolysins in biotechnology and health are additionally presented.
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Affiliation(s)
- Ajay P Nayak
- Allergy and Clinical Immunology Branch, National Institute for Occupational Safety and Health, 1095 Willowdale Road, Morgantown, WV 26505, USA.
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Amich J, Krappmann S. Deciphering metabolic traits of the fungal pathogen Aspergillus fumigatus: redundancy vs. essentiality. Front Microbiol 2012; 3:414. [PMID: 23264772 PMCID: PMC3525513 DOI: 10.3389/fmicb.2012.00414] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Accepted: 11/15/2012] [Indexed: 11/13/2022] Open
Abstract
Incidence rates of infections caused by environmental opportunistic fungi have risen over recent decades. Aspergillus species have emerged as serious threat for the immunecompromised, and detailed knowledge about virulence-determining traits is crucial for drug target identification. As a prime saprobe, A. fumigatus has evolved to efficiently adapt to various stresses and to sustain nutritional supply by osmotrophy, which is characterized by extracellular substrate digestion followed by efficient uptake of breakdown products that are then fed into the fungal primary metabolism. These intrinsic metabolic features are believed to be related with its virulence ability. The plethora of genes that encode underlying effectors has hampered their in-depth analysis with respect to pathogenesis. Recent developments in Aspergillus molecular biology allow conditional gene expression or comprehensive targeting of gene families to cope with redundancy. Furthermore, identification of essential genes that are intrinsically connected to virulence opens accurate perspectives for novel targets in antifungal therapy.
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Affiliation(s)
- Jorge Amich
- Research Center for Infectious Diseases, Julius-Maximilians-Universität Würzburg Würzburg, Germany
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42
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Farnell E, Rousseau K, Thornton DJ, Bowyer P, Herrick SE. Expression and secretion of Aspergillus fumigatus proteases are regulated in response to different protein substrates. Fungal Biol 2012; 116:1003-12. [PMID: 22954343 PMCID: PMC3605576 DOI: 10.1016/j.funbio.2012.07.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Revised: 07/06/2012] [Accepted: 07/09/2012] [Indexed: 01/12/2023]
Abstract
The ubiquitous filamentous fungus Aspergillus fumigatus secretes a number of allergens with protease activity and has been linked to a variety of allergic conditions such as Severe Asthma with Fungal Sensitization (SAFS) and Allergic Bronchopulmonary Aspergillosis (ABPA). However, it is unclear which allergen proteases are being secreted during fungal invasion and whether the local biological environment regulates their expression. Understanding the dynamic expression of allergen proteases during growth of A. fumigatus may lead to further characterisation of the pathogenesis of these disorders as well as improved standardisation in the commercial production of these allergens. Secretion of proteases during germination and early growth of A. fumigatus was investigated in response to various complex protein sources (pig lung homogenate, mucin or casein). Protease inhibitor studies demonstrated that A. fumigatus (AF293 strain) secretes predominately serine proteases during growth in pig lung based medium and mainly metalloproteases during growth in casein based medium but suppressed protease secretion in unmodified Vogel's minimal medium and secreted both types in mucin based medium. Analysis of gene transcription and protein identification by mass spectrometry showed that the matrix metalloprotease, Mep/Asp f 5 and the serine protease, Alp1/Asp f 13, were upregulated and secreted during growth in pig lung medium, whereas Alp1 was predominately expressed and secreted in mucin based medium. In casein medium, the matrix metalloprotease, Lap1, was also upregulated and secreted in addition to Mep and Alp1. These findings suggest that A. fumigatus is able to detect different complex proteins available as substrates in its environment and regulate protease secretion accordingly. There is a requirement for the standardisation of A. fumigatus allergen extracts used both in clinical diagnosis of A. fumigatus allergy and in research studies.
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Affiliation(s)
- Edward Farnell
- Respiratory Research Group, School of Translational Medicine, Faculty of Medical and Human Sciences, University of Manchester, Stopford Building, Manchester M13 9PT, UK
| | - Karine Rousseau
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Michael Smith Building, Manchester M13 9PT, UK
| | - David J. Thornton
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Michael Smith Building, Manchester M13 9PT, UK
| | - Paul Bowyer
- Respiratory Research Group, School of Translational Medicine, Faculty of Medical and Human Sciences, University of Manchester, Education and Research Centre, Wythenshawe Hospital, Manchester M23 9LT, UK
| | - Sarah E. Herrick
- Respiratory Research Group, School of Translational Medicine, Faculty of Medical and Human Sciences, University of Manchester, Stopford Building, Manchester M13 9PT, UK
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Menon V, Rao M. A low-molecular-mass aspartic protease inhibitor from a novel Penicillium sp.: implications in combating fungal infections. Microbiology (Reading) 2012; 158:1897-1907. [DOI: 10.1099/mic.0.058511-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Vishnu Menon
- Division of Biochemical Sciences, National Chemical Laboratory, Pune 411 008, India
| | - Mala Rao
- Division of Biochemical Sciences, National Chemical Laboratory, Pune 411 008, India
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Hagag S, Kubitschek-Barreira P, Neves GWP, Amar D, Nierman W, Shalit I, Shamir R, Lopes-Bezerra L, Osherov N. Transcriptional and proteomic analysis of the Aspergillus fumigatus ΔprtT protease-deficient mutant. PLoS One 2012; 7:e33604. [PMID: 22514608 PMCID: PMC3326020 DOI: 10.1371/journal.pone.0033604] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Accepted: 02/13/2012] [Indexed: 01/21/2023] Open
Abstract
Aspergillus fumigatus is the most common opportunistic mold pathogen of humans, infecting immunocompromised patients. The fungus invades the lungs and other organs, causing severe damage. Penetration of the pulmonary epithelium is a key step in the infectious process. A. fumigatus produces extracellular proteases to degrade the host structural barriers. The A. fumigatus transcription factor PrtT controls the expression of multiple secreted proteases. PrtT shows similarity to the fungal Gal4-type Zn(2)-Cys(6) DNA-binding domain of several transcription factors. In this work, we further investigate the function of this transcription factor by performing a transcriptional and a proteomic analysis of the ΔprtT mutant. Unexpectedly, microarray analysis revealed that in addition to the expected decrease in protease expression, expression of genes involved in iron uptake and ergosterol synthesis was dramatically decreased in the ΔprtT mutant. A second finding of interest is that deletion of prtT resulted in the upregulation of four secondary metabolite clusters, including genes for the biosynthesis of toxic pseurotin A. Proteomic analysis identified reduced levels of three secreted proteases (ALP1 protease, TppA, AFUA_2G01250) and increased levels of three secreted polysaccharide-degrading enzymes in the ΔprtT mutant possibly in response to its inability to derive sufficient nourishment from protein breakdown. This report highlights the complexity of gene regulation by PrtT, and suggests a potential novel link between the regulation of protease secretion and the control of iron uptake, ergosterol biosynthesis and secondary metabolite production in A. fumigatus.
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Affiliation(s)
- Shelly Hagag
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine Ramat-Aviv, Tel-Aviv, Israel
| | - Paula Kubitschek-Barreira
- Department of Cellular Biology, The Roberto Alcantara Gomes Institute of Biology, University of Estado Rio de Janeiro, Brazil
| | - Gabriela W. P. Neves
- Department of Cellular Biology, The Roberto Alcantara Gomes Institute of Biology, University of Estado Rio de Janeiro, Brazil
| | - David Amar
- Department of Computer Science, Tel-Aviv University, Ramat-Aviv, Tel-Aviv, Israel
| | - William Nierman
- The J. CraigVenter Institute, Rockville, Maryland, United States of America
| | - Itamar Shalit
- Sackler School of Medicine, Ramat Aviv, Tel-Aviv, Israel
| | - Ron Shamir
- Department of Computer Science, Tel-Aviv University, Ramat-Aviv, Tel-Aviv, Israel
| | - Leila Lopes-Bezerra
- Department of Cellular Biology, The Roberto Alcantara Gomes Institute of Biology, University of Estado Rio de Janeiro, Brazil
| | - Nir Osherov
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine Ramat-Aviv, Tel-Aviv, Israel
- * E-mail:
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Hartmann T, Cairns TC, Olbermann P, Morschhäuser J, Bignell EM, Krappmann S. Oligopeptide transport and regulation of extracellular proteolysis are required for growth of Aspergillus fumigatus on complex substrates but not for virulence. Mol Microbiol 2011; 82:917-35. [DOI: 10.1111/j.1365-2958.2011.07868.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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46
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Sriranganadane D, Waridel P, Salamin K, Feuermann M, Mignon B, Staib P, Neuhaus JM, Quadroni M, Monod M. Identification of novel secreted proteases during extracellular proteolysis by dermatophytes at acidic pH. Proteomics 2011; 11:4422-33. [PMID: 21919205 DOI: 10.1002/pmic.201100234] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Revised: 08/18/2011] [Accepted: 08/29/2011] [Indexed: 02/04/2023]
Abstract
The dermatophytes are a group of closely related fungi which are responsible for the great majority of superficial mycoses in humans and animals. Among various potential virulence factors, their secreted proteolytic activity attracts a lot of attention. Most dermatophyte-secreted proteases which have so far been isolated in vitro are neutral or alkaline enzymes. However, inspection of the recently decoded dermatophyte genomes revealed many other hypothetical secreted proteases, in particular acidic proteases similar to those characterized in Aspergillus spp. The validation of such genome predictions instigated the present study on two dermatophyte species, Microsporum canis and Arthroderma benhamiae. Both fungi were found to grow well in a protein medium at acidic pH, accompanied by extracellular proteolysis. Shotgun MS analysis of secreted protein revealed fundamentally different protease profiles during fungal growth in acidic versus neutral pH conditions. Most notably, novel dermatophyte-secreted proteases were identified at acidic pH such as pepsins, sedolisins and acidic carboxypeptidases. Therefore, our results not only support genome predictions, but demonstrate for the first time the secretion of acidic proteases by dermatophytes. Our findings also suggest the existence of different pathways of protein degradation into amino acids and short peptides in these highly specialized pathogenic fungi.
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Affiliation(s)
- Dev Sriranganadane
- Department of Dermatology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
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Watson DS, Feng X, Askew DS, Jambunathan K, Kodukula K, Galande AK. Substrate specifity profiling of the Aspergillus fumigatus proteolytic secretome reveals consensus motifs with predominance of Ile/Leu and Phe/Tyr. PLoS One 2011; 6:e21001. [PMID: 21695046 PMCID: PMC3117871 DOI: 10.1371/journal.pone.0021001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Accepted: 05/16/2011] [Indexed: 01/12/2023] Open
Abstract
Background The filamentous fungus Aspergillus fumigatus (AF) can cause devastating infections in immunocompromised individuals. Early diagnosis improves patient outcomes but remains challenging because of the limitations of current methods. To augment the clinician's toolkit for rapid diagnosis of AF infections, we are investigating AF secreted proteases as novel diagnostic targets. The AF genome encodes up to 100 secreted proteases, but fewer than 15 of these enzymes have been characterized thus far. Given the large number of proteases in the genome, studies focused on individual enzymes may overlook potential diagnostic biomarkers. Methodology and Principal Findings As an alternative, we employed a combinatorial library of internally quenched fluorogenic probes (IQFPs) to profile the global proteolytic secretome of an AF clinical isolate in vitro. Comparative protease activity profiling revealed 212 substrate sequences that were cleaved by AF secreted proteases but not by normal human serum. A central finding was that isoleucine, leucine, phenylalanine, and tyrosine predominated at each of the three variable positions of the library (44.1%, 59.1%, and 57.0%, respectively) among substrate sequences cleaved by AF secreted proteases. In contrast, fewer than 10% of the residues at each position of cleaved sequences were cationic or anionic. Consensus substrate motifs were cleaved by thermostable serine proteases that retained activity up to 50°C. Precise proteolytic cleavage sites were reliably determined by a simple, rapid mass spectrometry-based method, revealing predominantly non-prime side specificity. A comparison of the secreted protease activities of three AF clinical isolates revealed consistent protease substrate specificity fingerprints. However, secreted proteases of A. flavus, A. nidulans, and A. terreus strains exhibited striking differences in their proteolytic signatures. Conclusions This report provides proof-of-principle for the use of protease substrate specificity profiling to define the proteolytic secretome of Aspergillus fumigatus. Expansion of this technique to protease secretion during infection could lead to development of novel approaches to fungal diagnosis.
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Affiliation(s)
- Douglas S. Watson
- Center for Advanced Drug Research, Biosciences Division, SRI International, Harrisonburg, Virginia, United States of America
| | - Xizhi Feng
- Department of Pathology & Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - David S. Askew
- Department of Pathology & Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Kalyani Jambunathan
- Center for Advanced Drug Research, Biosciences Division, SRI International, Harrisonburg, Virginia, United States of America
| | - Krishna Kodukula
- Center for Advanced Drug Research, Biosciences Division, SRI International, Harrisonburg, Virginia, United States of America
| | - Amit K. Galande
- Center for Advanced Drug Research, Biosciences Division, SRI International, Harrisonburg, Virginia, United States of America
- * E-mail:
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Wartenberg D, Lapp K, Jacobsen ID, Dahse HM, Kniemeyer O, Heinekamp T, Brakhage AA. Secretome analysis of Aspergillus fumigatus reveals Asp-hemolysin as a major secreted protein. Int J Med Microbiol 2011; 301:602-11. [PMID: 21658997 DOI: 10.1016/j.ijmm.2011.04.016] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2011] [Revised: 04/07/2011] [Accepted: 04/10/2011] [Indexed: 11/28/2022] Open
Abstract
Surface-associated and secreted proteins represent primarily exposed components of Aspergillus fumigatus during host infection. Several secreted proteins are known to be involved in defense mechanisms or immune evasion, thus, probably contributing to pathogenicity. Furthermore, several secreted antigens were identified as possible biomarkers for the verification of diseases caused by Aspergillus species. Nevertheless, there is only limited knowledge about the composition of the secretome and about molecular functions of particular proteins. To identify secreted proteins potentially essential for virulence, the core secretome of A. fumigatus grown in minimal medium was determined. Two-dimensional gel electrophoretic separation and subsequent MALDI-TOF-MS/MS analyses resulted in the identification of 64 different proteins. Additionally, secretome analyses of A. fumigatus utilizing elastin, collagen or keratin as main carbon and nitrogen source were performed. Thereby, the alkaline serine protease Alp1 was identified as the most abundant protein and hence presumably represents an important protease during host infection. Interestingly, the Asp-hemolysin (Asp-HS), which belongs to the protein family of aegerolysins and which was often suggested to be involved in fungal virulence, was present in the secretome under all growth conditions tested. In addition, a second, non-secreted protein with an aegerolysin domain annotated as Asp-hemolysin-like (HS-like) protein can be found to be encoded in the genome of A. fumigatus. Generation and analysis of Asp-HS and HS-like deletion strains revealed no differences in phenotype compared to the corresponding wild-type strain. Furthermore, hemolysis and cytotoxicity was not altered in both single-deletion and double-deletion mutants lacking both aegerolysin genes. All mutant strains showed no attenuation in virulence in a mouse infection model for invasive pulmonary aspergillosis. Overall, this study provides a comprehensive analysis of secreted proteins of A. fumigatus and a detailed characterization of hemolysin mutants.
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Affiliation(s)
- Dirk Wartenberg
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (HKI), Jena, Germany
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Fleck CB, Schöbel F, Brock M. Nutrient acquisition by pathogenic fungi: nutrient availability, pathway regulation, and differences in substrate utilization. Int J Med Microbiol 2011; 301:400-7. [PMID: 21550848 DOI: 10.1016/j.ijmm.2011.04.007] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
All pathogenic microorganisms have in common that they need to feed on nutrients available from their host. Therefore, the specific interruption of metabolic pathways is a promising approach which could lead to the discovery of new antimicrobial drugs. However, nutrient availability strongly varies in respect to the infected host niche and pathogens may possess different strategies to acquire nutrients. This review focuses on the differences in regulation and use of key metabolic pathways during infection by pathogenic fungi, especially in the filamentous fungus Aspergillus fumigatus and the dimorphic yeast Candida albicans. Besides universal metabolic pathways, emphasis is given on pathways, which are absent in humans and might, therefore, suit as antifungal drug targets. Niche-specific nutrient availability and different physiological strategies complicate the identification of metabolic pathways, which are essential for all pathogens at each step of the infection process.
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Affiliation(s)
- Christian B Fleck
- Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute, Microbial Biochemistry and Physiology, Beutenbergstr. 11a, 07745 Jena, Germany
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50
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Ben-Ami R, Varga V, Lewis RE, May GS, Nierman WC, Kontoyiannis DP. Characterization of a 5-azacytidine-induced developmental Aspergillus fumigatus variant. Virulence 2011; 1:164-73. [PMID: 21178435 DOI: 10.4161/viru.1.3.11750] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The hypomethylating agent 5-azacytidine (5AC) is widely used in patients at risk of invasive mycoses. We sought to determine whether 5AC affects the developmental competence and virulence of Aspergillus fumigatus. Incubation of A. fumigatus strain 293 with 5AC induced high-frequency conversion to a fluffy-variant (Af293 (FL) ). The conidiation defect was bypassed by exposing Af293 (FL) to light during the initial 18 hours of growth on solid media. Transcriptional profiling revealed differential expression of multiple genes involved in G-protein signaling, including a putative G-protein coupled photoreceptor (opsin), suggesting that impaired signaling through a light-responsive pathway upstream of brlA is responsible for this phenotype. Af293 (FL) was fully virulent in fruit fly and murine models of invasive aspergillosis. Moreover, Af293 (FL) overexpressed aspergillopepsin F, had increased elastase activity and was more angioinvasive than the parental wild-type strain. The 5AC-induced A. fumigatus fluffy variant illustrates the potential effects of chemotherapeutic agents on the developmental and pathobiologic characteristics of opportunistic fungi.
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Affiliation(s)
- Ronen Ben-Ami
- Department of Infectious Diseases, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
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