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Theobald S, Vesth TC, Geib E, Nybo JL, Frisvad JC, Larsen TO, Kuo A, LaButti K, Lyhne EK, Kjærbølling I, Ledsgaard L, Barry K, Clum A, Chen C, Nolan M, Sandor L, Lipzen A, Mondo S, Pangilinan J, Salamov A, Riley R, Wiebenga A, Müller A, Kun RS, dos Santos Gomes AC, Henrissat B, Magnuson JK, Simmons BA, Mäkelä MR, Mortensen UH, Grigoriev IV, Brock M, Baker SE, de Vries RP, Andersen MR. Genomic Analysis of Aspergillus Section Terrei Reveals a High Potential in Secondary Metabolite Production and Plant Biomass Degradation. J Fungi (Basel) 2024; 10:507. [PMID: 39057392 PMCID: PMC11278011 DOI: 10.3390/jof10070507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2024] [Revised: 07/17/2024] [Accepted: 07/18/2024] [Indexed: 07/28/2024] Open
Abstract
Aspergillus terreus has attracted interest due to its application in industrial biotechnology, particularly for the production of itaconic acid and bioactive secondary metabolites. As related species also seem to possess a prosperous secondary metabolism, they are of high interest for genome mining and exploitation. Here, we present draft genome sequences for six species from Aspergillus section Terrei and one species from Aspergillus section Nidulantes. Whole-genome phylogeny confirmed that section Terrei is monophyletic. Genome analyses identified between 70 and 108 key secondary metabolism genes in each of the genomes of section Terrei, the highest rate found in the genus Aspergillus so far. The respective enzymes fall into 167 distinct families with most of them corresponding to potentially unique compounds or compound families. Moreover, 53% of the families were only found in a single species, which supports the suitability of species from section Terrei for further genome mining. Intriguingly, this analysis, combined with heterologous gene expression and metabolite identification, suggested that species from section Terrei use a strategy for UV protection different to other species from the genus Aspergillus. Section Terrei contains a complete plant polysaccharide degrading potential and an even higher cellulolytic potential than other Aspergilli, possibly facilitating additional applications for these species in biotechnology.
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Affiliation(s)
- Sebastian Theobald
- Department of Biotechnology and Bioengineering, Technical University of Denmark, 2800 Kongens Lyngby, Denmark; (S.T.); (T.C.V.); (J.L.N.); (J.C.F.); (T.O.L.); (E.K.L.); (I.K.); (L.L.); (B.H.); (U.H.M.)
| | - Tammi C. Vesth
- Department of Biotechnology and Bioengineering, Technical University of Denmark, 2800 Kongens Lyngby, Denmark; (S.T.); (T.C.V.); (J.L.N.); (J.C.F.); (T.O.L.); (E.K.L.); (I.K.); (L.L.); (B.H.); (U.H.M.)
| | - Elena Geib
- School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, UK; (E.G.); (M.B.)
| | - Jane L. Nybo
- Department of Biotechnology and Bioengineering, Technical University of Denmark, 2800 Kongens Lyngby, Denmark; (S.T.); (T.C.V.); (J.L.N.); (J.C.F.); (T.O.L.); (E.K.L.); (I.K.); (L.L.); (B.H.); (U.H.M.)
| | - Jens C. Frisvad
- Department of Biotechnology and Bioengineering, Technical University of Denmark, 2800 Kongens Lyngby, Denmark; (S.T.); (T.C.V.); (J.L.N.); (J.C.F.); (T.O.L.); (E.K.L.); (I.K.); (L.L.); (B.H.); (U.H.M.)
| | - Thomas O. Larsen
- Department of Biotechnology and Bioengineering, Technical University of Denmark, 2800 Kongens Lyngby, Denmark; (S.T.); (T.C.V.); (J.L.N.); (J.C.F.); (T.O.L.); (E.K.L.); (I.K.); (L.L.); (B.H.); (U.H.M.)
| | - Alan Kuo
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; (A.K.); (K.L.); (K.B.); (A.C.); (C.C.); (M.N.); (L.S.); (A.L.); (S.M.); (J.P.); (A.S.); (R.R.); (I.V.G.)
| | - Kurt LaButti
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; (A.K.); (K.L.); (K.B.); (A.C.); (C.C.); (M.N.); (L.S.); (A.L.); (S.M.); (J.P.); (A.S.); (R.R.); (I.V.G.)
| | - Ellen K. Lyhne
- Department of Biotechnology and Bioengineering, Technical University of Denmark, 2800 Kongens Lyngby, Denmark; (S.T.); (T.C.V.); (J.L.N.); (J.C.F.); (T.O.L.); (E.K.L.); (I.K.); (L.L.); (B.H.); (U.H.M.)
| | - Inge Kjærbølling
- Department of Biotechnology and Bioengineering, Technical University of Denmark, 2800 Kongens Lyngby, Denmark; (S.T.); (T.C.V.); (J.L.N.); (J.C.F.); (T.O.L.); (E.K.L.); (I.K.); (L.L.); (B.H.); (U.H.M.)
| | - Line Ledsgaard
- Department of Biotechnology and Bioengineering, Technical University of Denmark, 2800 Kongens Lyngby, Denmark; (S.T.); (T.C.V.); (J.L.N.); (J.C.F.); (T.O.L.); (E.K.L.); (I.K.); (L.L.); (B.H.); (U.H.M.)
| | - Kerrie Barry
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; (A.K.); (K.L.); (K.B.); (A.C.); (C.C.); (M.N.); (L.S.); (A.L.); (S.M.); (J.P.); (A.S.); (R.R.); (I.V.G.)
| | - Alicia Clum
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; (A.K.); (K.L.); (K.B.); (A.C.); (C.C.); (M.N.); (L.S.); (A.L.); (S.M.); (J.P.); (A.S.); (R.R.); (I.V.G.)
| | - Cindy Chen
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; (A.K.); (K.L.); (K.B.); (A.C.); (C.C.); (M.N.); (L.S.); (A.L.); (S.M.); (J.P.); (A.S.); (R.R.); (I.V.G.)
| | - Matt Nolan
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; (A.K.); (K.L.); (K.B.); (A.C.); (C.C.); (M.N.); (L.S.); (A.L.); (S.M.); (J.P.); (A.S.); (R.R.); (I.V.G.)
| | - Laura Sandor
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; (A.K.); (K.L.); (K.B.); (A.C.); (C.C.); (M.N.); (L.S.); (A.L.); (S.M.); (J.P.); (A.S.); (R.R.); (I.V.G.)
| | - Anna Lipzen
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; (A.K.); (K.L.); (K.B.); (A.C.); (C.C.); (M.N.); (L.S.); (A.L.); (S.M.); (J.P.); (A.S.); (R.R.); (I.V.G.)
| | - Stephen Mondo
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; (A.K.); (K.L.); (K.B.); (A.C.); (C.C.); (M.N.); (L.S.); (A.L.); (S.M.); (J.P.); (A.S.); (R.R.); (I.V.G.)
| | - Jasmyn Pangilinan
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; (A.K.); (K.L.); (K.B.); (A.C.); (C.C.); (M.N.); (L.S.); (A.L.); (S.M.); (J.P.); (A.S.); (R.R.); (I.V.G.)
| | - Asaf Salamov
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; (A.K.); (K.L.); (K.B.); (A.C.); (C.C.); (M.N.); (L.S.); (A.L.); (S.M.); (J.P.); (A.S.); (R.R.); (I.V.G.)
| | - Robert Riley
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; (A.K.); (K.L.); (K.B.); (A.C.); (C.C.); (M.N.); (L.S.); (A.L.); (S.M.); (J.P.); (A.S.); (R.R.); (I.V.G.)
| | - Ad Wiebenga
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute and Fungal Molecular Physiology, Utrecht University, 3584 Utrecht, The Netherlands; (A.W.); (A.M.); (R.S.K.); (A.C.d.S.G.)
| | - Astrid Müller
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute and Fungal Molecular Physiology, Utrecht University, 3584 Utrecht, The Netherlands; (A.W.); (A.M.); (R.S.K.); (A.C.d.S.G.)
| | - Roland S. Kun
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute and Fungal Molecular Physiology, Utrecht University, 3584 Utrecht, The Netherlands; (A.W.); (A.M.); (R.S.K.); (A.C.d.S.G.)
| | - Ana Carolina dos Santos Gomes
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute and Fungal Molecular Physiology, Utrecht University, 3584 Utrecht, The Netherlands; (A.W.); (A.M.); (R.S.K.); (A.C.d.S.G.)
| | - Bernard Henrissat
- Department of Biotechnology and Bioengineering, Technical University of Denmark, 2800 Kongens Lyngby, Denmark; (S.T.); (T.C.V.); (J.L.N.); (J.C.F.); (T.O.L.); (E.K.L.); (I.K.); (L.L.); (B.H.); (U.H.M.)
- Department of Biological Sciences, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Jon K. Magnuson
- Environmental Molecular Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99354, USA; (J.K.M.); (B.A.S.)
- US Department of Energy Joint Bioenergy Institute, 5885 Hollis St., Emeryville, CA 94608, USA
| | - Blake A. Simmons
- Environmental Molecular Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99354, USA; (J.K.M.); (B.A.S.)
- Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Miia R. Mäkelä
- Department of Microbiology, University of Helsinki, Viikinkaari 9, 00014 Helsinki, Finland;
| | - Uffe H. Mortensen
- Department of Biotechnology and Bioengineering, Technical University of Denmark, 2800 Kongens Lyngby, Denmark; (S.T.); (T.C.V.); (J.L.N.); (J.C.F.); (T.O.L.); (E.K.L.); (I.K.); (L.L.); (B.H.); (U.H.M.)
| | - Igor V. Grigoriev
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; (A.K.); (K.L.); (K.B.); (A.C.); (C.C.); (M.N.); (L.S.); (A.L.); (S.M.); (J.P.); (A.S.); (R.R.); (I.V.G.)
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA 94720, USA
| | - Matthias Brock
- School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, UK; (E.G.); (M.B.)
| | - Scott E. Baker
- Environmental Molecular Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99354, USA; (J.K.M.); (B.A.S.)
- US Department of Energy Joint Bioenergy Institute, 5885 Hollis St., Emeryville, CA 94608, USA
| | - Ronald P. de Vries
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute and Fungal Molecular Physiology, Utrecht University, 3584 Utrecht, The Netherlands; (A.W.); (A.M.); (R.S.K.); (A.C.d.S.G.)
| | - Mikael R. Andersen
- Department of Biotechnology and Bioengineering, Technical University of Denmark, 2800 Kongens Lyngby, Denmark; (S.T.); (T.C.V.); (J.L.N.); (J.C.F.); (T.O.L.); (E.K.L.); (I.K.); (L.L.); (B.H.); (U.H.M.)
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Huang Z, Wu D, Yang S, Fu W, Ma D, Yao Y, Lin H, Yuan J, Yang Y, Zhuang Z. Regulation of Fungal Morphogenesis and Pathogenicity of Aspergillus flavus by Hexokinase AfHxk1 through Its Domain Hexokinase_2. J Fungi (Basel) 2023; 9:1077. [PMID: 37998882 PMCID: PMC10671980 DOI: 10.3390/jof9111077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 10/28/2023] [Accepted: 11/02/2023] [Indexed: 11/25/2023] Open
Abstract
As a filamentous pathogenic fungus with high-yield of aflatoxin B1, Aspergillus flavus is commonly found in various agricultural products. It is crucial to develop effective strategies aimed at the prevention of the contamination of A. flavus and aflatoxin. Hexokinase AfHxk1 is a critical enzyme in fungal glucose metabolism. However, the role of AfHxk1 in A. flavus development, aflatoxin biosynthesis, and virulence has not yet been explored. In this study, afHxk1 gene deletion mutant (ΔafHxk1), complementary strain (Com-afHxk1), and the domain deletion strains (afHxk1ΔD1 and afHxk1ΔD2) were constructed by homologous recombination. Phenotype study and RT-qPCR revealed that AfHxk1 upregulates mycelium growth and spore and sclerotia formation, but downregulates AFB1 biosynthesis through related classical signaling pathways. Invading models and environmental stress analysis revealed that through involvement in carbon source utilization, conidia germination, and the sensitivity response of A. flavus to a series of environmental stresses, AfHxk1 deeply participates in the regulation of pathogenicity of A. flavus to crop kernels and Galleria mellonella larvae. The construction of domain deletion strains, afHxk1ΔD1 and afHxk1ΔD2, further revealed that AfHxk1 regulates the morphogenesis, mycotoxin biosynthesis, and the fungal pathogenicity mainly through its domain, Hexokinase_2. The results of this study revealed the biological role of AfHxk1 in Aspergillus spp., and might provide a novel potential target for the early control of the contamination of A. flavus.
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Affiliation(s)
- Zongting Huang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Z.H.); (D.W.); (S.Y.); (W.F.); (Y.Y.); (H.L.); (J.Y.); (Y.Y.)
| | - Dandan Wu
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Z.H.); (D.W.); (S.Y.); (W.F.); (Y.Y.); (H.L.); (J.Y.); (Y.Y.)
| | - Sile Yang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Z.H.); (D.W.); (S.Y.); (W.F.); (Y.Y.); (H.L.); (J.Y.); (Y.Y.)
| | - Wangzhuo Fu
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Z.H.); (D.W.); (S.Y.); (W.F.); (Y.Y.); (H.L.); (J.Y.); (Y.Y.)
| | - Dongmei Ma
- College of Animal Sciences (College of Bee Science), Fujian Agriculture and Forestry University, Fuzhou 350002, China;
| | - Yanfang Yao
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Z.H.); (D.W.); (S.Y.); (W.F.); (Y.Y.); (H.L.); (J.Y.); (Y.Y.)
| | - Hong Lin
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Z.H.); (D.W.); (S.Y.); (W.F.); (Y.Y.); (H.L.); (J.Y.); (Y.Y.)
| | - Jun Yuan
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Z.H.); (D.W.); (S.Y.); (W.F.); (Y.Y.); (H.L.); (J.Y.); (Y.Y.)
| | - Yanling Yang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Z.H.); (D.W.); (S.Y.); (W.F.); (Y.Y.); (H.L.); (J.Y.); (Y.Y.)
| | - Zhenhong Zhuang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Z.H.); (D.W.); (S.Y.); (W.F.); (Y.Y.); (H.L.); (J.Y.); (Y.Y.)
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Peres da Silva R, Brock M. NIH4215: A mutation-prone thiamine auxotrophic clinical Aspergillus fumigatus isolate. FRONTIERS IN FUNGAL BIOLOGY 2022; 3:908343. [PMID: 37746208 PMCID: PMC10512395 DOI: 10.3389/ffunb.2022.908343] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 06/30/2022] [Indexed: 09/26/2023]
Abstract
Aspergillus fumigatus is the main cause of life-threatening invasive aspergillosis. Despite the availability of various antifungals, therapy remains challenging and requires further studies. Accordingly, the clinical A. fumigatus isolate NIH4215 deriving from a fatal case of human pulmonary aspergillosis has frequently been used in drug efficacy studies. Unexpectedly, our initial attempts to generate a bioluminescent reporter of strain NIH4215 for in vivo drug efficacy studies failed, as NIH4215 was unable to grow on defined minimal medium. Subsequent analyses discovered a previously undescribed thiamine auxotrophy of strain NIH4215 and transformation with thiamine biosynthesis genes from A. fumigatus strain Af293 identified the nmt1 gene as cause of the thiamine auxotrophy. Sequencing of the defective nmt1 gene revealed the loss of a cysteine codon within an essential iron-binding motif. Subsequently, the wild-type nmt1 gene was successfully used to generate a bioluminescent reporter strain in NIH4215 by simultaneously deleting the akuB locus. The resulting bioluminescent ΔakuB strains showed a high frequency of homologous integration as confirmed by generation of pyrG and niaD deletion mutants. When tested in a Galleria mellonella infection model, neither thiamine auxotrophy nor the deletion of the akuB locus had a significant effect on virulence. However, besides thiamine auxotrophy, sectors with altered morphology and albino mutants frequently arose on colony edges of strain NIH4215 and its derivatives, and stable albino mutants were successfully isolated. A proposed increased mutation rate of NIH4215 was confirmed by screening for spontaneous occurrence of fluoorotic acid resistant mutants. Independent mutations in the pyrG and pyrE gene were identified in the fluoroorotic acid resistant NIH4215 isolates and the frequency of mutation was by at least one order of magnitude higher than that observed for the clinical A. fumigatus isolate CBS144.89. In summary, despite its virulence in animal models, strain NIH4215 is a thiamine auxotroph and prone to accumulate mutations. Our results suggest that thiamine biosynthesis is dispensable for host infection and mutation-prone strains such as NIH4215 could potentially facilitate the evolution of azole resistant strains as increasingly observed in the environment.
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Affiliation(s)
| | - Matthias Brock
- University of Nottingham, School of Life Sciences, University Park, Nottingham, United Kingdom
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Resendiz-Sharpe A, da Silva RP, Geib E, Vanderbeke L, Seldeslachts L, Hupko C, Brock M, Lagrou K, Vande Velde G. Longitudinal multimodal imaging-compatible mouse model of triazole-sensitive and -resistant invasive pulmonary aspergillosis. Dis Model Mech 2022; 15:274857. [PMID: 35352801 PMCID: PMC8990085 DOI: 10.1242/dmm.049165] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Accepted: 01/09/2022] [Indexed: 12/18/2022] Open
Abstract
Invasive pulmonary aspergillosis (IPA) caused by the mold Aspergillus fumigatus is one of the most important life-threatening infections in immunocompromised patients. The alarming increase of isolates resistant to the first-line recommended antifungal therapy urges more insights into triazole-resistant A. fumigatus infections. In this study, we systematically optimized a longitudinal multimodal imaging-compatible neutropenic mouse model of IPA. Reproducible rates of pulmonary infection were achieved through immunosuppression (sustained neutropenia) with 150 mg/kg cyclophosphamide at day −4, −1 and 2, and an orotracheal inoculation route in both sexes. Furthermore, increased sensitivity of in vivo bioluminescence imaging for fungal burden detection, as early as the day after infection, was achieved by optimizing luciferin dosing and through engineering isogenic red-shifted bioluminescent A. fumigatus strains, one wild type and two triazole-resistant mutants. We successfully tested appropriate and inappropriate antifungal treatment scenarios in vivo with our optimized multimodal imaging strategy, according to the in vitro susceptibility of our luminescent fungal strains. Therefore, we provide novel essential mouse models with sensitive imaging tools for investigating IPA development and therapy in triazole-susceptible and triazole-resistant scenarios. Summary: A novel reproducible longitudinal multimodal imaging-compatible neutropenic mouse model of invasive pulmonary aspergillosis provides increased early fungal detection through novel red-shifted luciferase-expressing triazole-susceptible and -resistant Aspergillus fumigatus strains, and boosted bioluminescence.
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Affiliation(s)
- Agustin Resendiz-Sharpe
- Laboratory of Clinical Microbiology, Department of Microbiology, Immunology and Transplantation, Katholieke Universiteit (KU) Leuven, 3000 Leuven, Belgium
| | - Roberta Peres da Silva
- Fungal Biology Group, School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Elena Geib
- Fungal Biology Group, School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Lore Vanderbeke
- Laboratory of Clinical Microbiology, Department of Microbiology, Immunology and Transplantation, Katholieke Universiteit (KU) Leuven, 3000 Leuven, Belgium
| | - Laura Seldeslachts
- Department of Imaging and Pathology, Biomedical MRI unit/MoSAIC, KU Leuven, 3000 Leuven, Belgium
| | - Charlien Hupko
- Laboratory of Clinical Microbiology, Department of Microbiology, Immunology and Transplantation, Katholieke Universiteit (KU) Leuven, 3000 Leuven, Belgium
| | - Matthias Brock
- Fungal Biology Group, School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Katrien Lagrou
- Laboratory of Clinical Microbiology, Department of Microbiology, Immunology and Transplantation, Katholieke Universiteit (KU) Leuven, 3000 Leuven, Belgium.,Department of Laboratory Medicine and National Reference Centre for Mycosis, Excellence Centre for Medical Mycology (ECMM), University Hospitals Leuven, 3000 Leuven, Belgium
| | - Greetje Vande Velde
- Department of Imaging and Pathology, Biomedical MRI unit/MoSAIC, KU Leuven, 3000 Leuven, Belgium
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Neofunctionalization of Glycolytic Enzymes: An Evolutionary Route to Plant Parasitism in the Oomycete Phytophthora nicotianae. Microorganisms 2022; 10:microorganisms10020281. [PMID: 35208735 PMCID: PMC8879444 DOI: 10.3390/microorganisms10020281] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 01/12/2022] [Accepted: 01/23/2022] [Indexed: 02/04/2023] Open
Abstract
Oomycetes, of the genus Phytophthora, comprise of some of the most devastating plant pathogens. Parasitism of Phytophthora results from evolution from an autotrophic ancestor and adaptation to a wide range of environments, involving metabolic adaptation. Sequence mining showed that Phytophthora spp. display an unusual repertoire of glycolytic enzymes, made of multigene families and enzyme replacements. To investigate the impact of these gene duplications on the biology of Phytophthora and, eventually, identify novel functions associated to gene expansion, we focused our study on the first glycolytic step on P. nicotianae, a broad host range pathogen. We reveal that this step is committed by a set of three glucokinase types that differ by their structure, enzymatic properties, and evolutionary histories. In addition, they are expressed differentially during the P. nicotianae life cycle, including plant infection. Last, we show that there is a strong association between the expression of a glucokinase member in planta and extent of plant infection. Together, these results suggest that metabolic adaptation is a component of the processes underlying evolution of parasitism in Phytophthora, which may possibly involve the neofunctionalization of metabolic enzymes.
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Seldeslachts L, Vanderbeke L, Fremau A, Reséndiz-Sharpe A, Jacobs C, Laeveren B, Ostyn T, Naesens L, Brock M, Van De Veerdonk FL, Humblet-Baron S, Verbeken E, Lagrou K, Wauters J, Vande Velde G. Early oseltamivir reduces risk for influenza-associated aspergillosis in a double-hit murine model. Virulence 2021; 12:2493-2508. [PMID: 34546839 PMCID: PMC8923074 DOI: 10.1080/21505594.2021.1974327] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 07/09/2021] [Accepted: 08/25/2021] [Indexed: 12/01/2022] Open
Abstract
Invasive pulmonary aspergillosis (IPA) is a life-threatening fungal infection occurring mainly in immunocompromised patients. We recently identified IPA as an emerging co-infection with high mortality in critically ill, but otherwise immunocompetent influenza patients. The neuraminidase inhibitor oseltamivir is the current standard-of-care treatment in hospitalized influenza patients; however, its efficacy in influenza-associated pulmonary aspergillosis (IAPA) is not known. Therefore, we have established an imaging-supported double-hit mouse model to investigate the therapeutic effect of oseltamivir on the development of IAPA. Immunocompetent mice received intranasal instillation influenza A or PBS followed by orotracheal inoculation with Aspergillus fumigatus 4 days later. Oseltamivir treatment or placebo was started at day 0, day 2, or day 4. Daily monitoring included micro-computed tomography and bioluminescence imaging of pneumonia and fungal burden. Non-invasive biomarkers were complemented with imaging, molecular, immunological, and pathological analysis. Influenza virus-infected immunocompetent mice developed proven airway IPA upon co-infection with Aspergillus fumigatus, whereas non-influenza-infected mice fully cleared Aspergillus, confirming influenza as a risk factor for developing IPA. Longitudinal micro-CT showed pulmonary lesions after influenza infection worsening after Aspergillus co-infection, congruent with bioluminescence imaging and histology confirming Aspergillus pneumonia. Early oseltamivir treatment prevented severe influenza pneumonia and mitigated the development of IPA and associated mortality. A time-dependent treatment effect was consistently observed with imaging, molecular, and pathological analyses. Hence, our findings underscore the importance of initiating oseltamivir as soon as possible, to suppress influenza infection and mitigate the risk of potentially lethal IAPA disease.
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Affiliation(s)
- Laura Seldeslachts
- Department of Imaging and Pathology, Biomedical MRI unit/MoSAIC, Ku Leuven, Leuven, Belgium
| | - Lore Vanderbeke
- Department of Microbiology, Immunology and Transplantation, Laboratory of Clinical Bacteriology and Mycology, Ku Leuven, Leuven, Belgium
| | - Astrid Fremau
- Department of Imaging and Pathology, Biomedical MRI unit/MoSAIC, Ku Leuven, Leuven, Belgium
| | - Agustin Reséndiz-Sharpe
- Department of Microbiology, Immunology and Transplantation, Laboratory of Clinical Bacteriology and Mycology, Ku Leuven, Leuven, Belgium
| | - Cato Jacobs
- Department of Microbiology, Immunology and Transplantation,Laboratory for Clinical Infectious and Inflammatory Disorders, Ku Leuven, Leuven, Belgium
| | - Bo Laeveren
- Department of Imaging and Pathology, Biomedical MRI unit/MoSAIC, Ku Leuven, Leuven, Belgium
| | - Tessa Ostyn
- Department of Imaging and Pathology, Biomedical MRI unit/MoSAIC, Ku Leuven, Leuven, Belgium
| | - Lieve Naesens
- Department of Microbiology, Immunology and Transplantation, Laboratory of Virology and Chemotherapy (Rega Institute), Ku Leuven, Leuven, Belgium
| | - Matthias Brock
- Fungal Biology Group, School of Life Sciences, University of Nottingham, Nottingham, UK
| | | | - Stephanie Humblet-Baron
- Department of Microbiology, Immunology and Transplantation, Laboratory of Adaptive Immunity, Ku Leuven, Leuven, Belgium
| | - Erik Verbeken
- Department of Imaging and Pathology, Ku Leuven, Leuven, Belgium
| | - Katrien Lagrou
- Department of Microbiology, Immunology and Transplantation, Laboratory of Clinical Bacteriology and Mycology, Ku Leuven, Leuven, Belgium
| | - Joost Wauters
- Department of Microbiology, Immunology and Transplantation,Laboratory for Clinical Infectious and Inflammatory Disorders, Ku Leuven, Leuven, Belgium
| | - Greetje Vande Velde
- Department of Imaging and Pathology, Biomedical MRI unit/MoSAIC, Ku Leuven, Leuven, Belgium
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Polozsányi Z, Kaliňák M, Babjak M, Šimkovič M, Varečka Ľ. How to enter the state of dormancy? A suggestion by Trichoderma atroviride conidia. Fungal Biol 2021; 125:934-949. [PMID: 34649680 DOI: 10.1016/j.funbio.2021.07.001] [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: 07/18/2020] [Revised: 06/12/2021] [Accepted: 07/01/2021] [Indexed: 10/20/2022]
Abstract
It is generally accepted that conidia, propagules of filamentous fungi, exist in the state of dormancy. This state is defined mostly phenomenologically, e.g., by germination requirements. Its molecular characteristics are scarce and are concentrated on the water or osmolyte content, and/or respiration. However, a question of whether conidia are metabolic or ametabolic forms of life cannot be answered on the basis of available experimental data. In other words, are mature conidia open thermodynamic systems as are mycelia, or do they become closed upon the transition to the dormant state? In this article, we present observations which may help to define the transition of freshly formed conidia to the putative dormant forms using measurements of selected enzyme activities, 1H- and 13C-NMR and LC-MS-metabolomes, and 14C-bicarbonate or 45Ca2+ inward transport. We have found that Trichoderma atroviride and Aspergillus niger conidia arrest the 45Ca2+ uptake during the development stopping thereby the cyclic (i.e., bidirectional) Ca2+ flow existing in vegetative mycelia and conidia of T. atroviride across the cytoplasmic membrane. Furthermore, we have found that the activity of α-ketoglutarate dehydrogenase was rendered completely inactive after 3 weeks from the conidia formation unlike of other central carbon metabolism enzymes. This may explain the loss of conidial respiration. Finally, we found that conidia take up the H14CO3- and convert it into few stable compounds within 80 d of maturation, with minor quantitative differences in the extent of this process. The uptake of H13CO3- confirmed these observation and demonstrated the incorporation of H13CO3- even in the absence of exogenous substrates. These results suggest that T. atroviride conidia remain metabolically active during first ten weeks of maturation. Under these circumstances, their metabolism displays features similar to those of chemoautotrophic microorganisms. However, the Ca2+ homeostasis changed from the open to the closed thermodynamic state during the early period of conidial maturation. These results may be helpful for studying the conidial ageing and/or maturation, and for defining the conidial dormant state in biochemical terms.
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Affiliation(s)
- Zoltán Polozsányi
- Institute of Biochemistry and Microbiology, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, 812 37, Bratislava, Slovakia
| | - Michal Kaliňák
- Central Laboratories, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, 812 37, Bratislava, Slovakia
| | - Matej Babjak
- Department of Organic Chemistry, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, 812 37, Bratislava, Slovakia
| | - Martin Šimkovič
- Institute of Biochemistry and Microbiology, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, 812 37, Bratislava, Slovakia.
| | - Ľudovít Varečka
- Institute of Biochemistry and Microbiology, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, 812 37, Bratislava, Slovakia
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8
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Gressler AE, Volke D, Firacative C, Schnabel CL, Müller U, Krizsan A, Schulze-Richter B, Brock M, Brombacher F, Escandón P, Hoffmann R, Alber G. Identification of Disease-Associated Cryptococcal Proteins Reactive With Serum IgG From Cryptococcal Meningitis Patients. Front Immunol 2021; 12:709695. [PMID: 34367172 PMCID: PMC8342929 DOI: 10.3389/fimmu.2021.709695] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 06/21/2021] [Indexed: 01/16/2023] Open
Abstract
Cryptococcus neoformans, an opportunistic fungal pathogen ubiquitously present in the environment, causes cryptococcal meningitis (CM) mainly in immunocompromised patients, such as AIDS patients. We aimed to identify disease-associated cryptococcal protein antigens targeted by the human humoral immune response. Therefore, we used sera from Colombian CM patients, with or without HIV infection, and from healthy individuals living in the same region. Serological analysis revealed increased titers of anti-cryptococcal IgG in HIV-negative CM patients, but not HIV-positive CM patients, compared to healthy controls. In contrast, titers of anti-cryptococcal IgM were not affected by CM. Furthermore, we detected pre-existing IgG and IgM antibodies even in sera from healthy individuals. The observed induction of anti-cryptococcal IgG but not IgM during CM was supported by analysis of sera from C. neoformans-infected mice. Stronger increase in IgG was found in wild type mice with high lung fungal burden compared to IL-4Rα-deficient mice showing low lung fungal burden. To identify the proteins targeted by human anti-cryptococcal IgG antibodies, we applied a quantitative 2D immunoproteome approach identifying cryptococcal protein spots preferentially recognized by sera from CM patients or healthy individuals followed by mass spectrometry analysis. Twenty-three cryptococcal proteins were recombinantly expressed and confirmed to be immunoreactive with human sera. Fourteen of them were newly described as immunoreactive proteins. Twelve proteins were classified as disease-associated antigens, based on significantly stronger immunoreactivity with sera from CM patients compared to healthy individuals. The proteins identified in our screen significantly expand the pool of cryptococcal proteins with potential for (i) development of novel anti-cryptococcal agents based on implications in cryptococcal virulence or survival, or (ii) development of an anti-cryptococcal vaccine, as several candidates lack homology to human proteins and are localized extracellularly. Furthermore, this study defines pre-existing anti-cryptococcal immunoreactivity in healthy individuals at a molecular level, identifying target antigens recognized by sera from healthy control persons.
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Affiliation(s)
- A Elisabeth Gressler
- Institute of Immunology, Faculty of Veterinary Medicine, Leipzig University, Leipzig, Germany
| | - Daniela Volke
- Institute of Bioanalytical Chemistry, Leipzig University, Leipzig, Germany
| | - Carolina Firacative
- Studies in Translational Microbiology and Emerging Diseases (MICROS) Research Group, School of Medicine and Health Sciences, Universidad del Rosario, Bogota, Colombia
| | - Christiane L Schnabel
- Institute of Immunology, Faculty of Veterinary Medicine, Leipzig University, Leipzig, Germany
| | - Uwe Müller
- Institute of Immunology, Faculty of Veterinary Medicine, Leipzig University, Leipzig, Germany
| | - Andor Krizsan
- Institute of Bioanalytical Chemistry, Leipzig University, Leipzig, Germany
| | - Bianca Schulze-Richter
- Institute of Immunology, Faculty of Veterinary Medicine, Leipzig University, Leipzig, Germany
| | - Matthias Brock
- Fungal Genetics and Biology Group, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Frank Brombacher
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Cape Town Component, Cape Town, South Africa
| | | | - Ralf Hoffmann
- Institute of Bioanalytical Chemistry, Leipzig University, Leipzig, Germany
| | - Gottfried Alber
- Institute of Immunology, Faculty of Veterinary Medicine, Leipzig University, Leipzig, Germany
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9
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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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10
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Pennerman KK, Yin G, Glenn AE, Bennett JW. Identifying candidate Aspergillus pathogenicity factors by annotation frequency. BMC Microbiol 2020; 20:342. [PMID: 33176679 PMCID: PMC7661267 DOI: 10.1186/s12866-020-02031-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 11/02/2020] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Members of the genus Aspergillus display a variety of lifestyles, ranging from saprobic to pathogenic on plants and/or animals. Increased genome sequencing of economically important members of the genus permits effective use of "-omics" comparisons between closely related species and strains to identify candidate genes that may contribute to phenotypes of interest, especially relating to pathogenicity. Protein-coding genes were predicted from 216 genomes of 12 Aspergillus species, and the frequencies of various structural aspects (exon count and length, intron count and length, GC content, and codon usage) and functional annotations (InterPro, Gene Ontology, and Kyoto Encyclopedia of Genes and Genomes terms) were compared. RESULTS Using principal component analyses, the three sets of functional annotations for each strain were clustered by species. The species clusters appeared to separate by pathogenicity on plants along the first dimensions, which accounted for over 20% of the variance. More annotations for genes encoding pectinases and secondary metabolite biosynthetic enzymes were assigned to phytopathogenic strains from species such as Aspergillus flavus. In contrast, Aspergillus fumigatus strains, which are pathogenic to animals but not plants, were assigned relatively more terms related to phosphate transferases, and carbohydrate and amino-sugar metabolism. Analyses of publicly available RNA-Seq data indicated that one A. fumigatus protein among 17 amino-sugar processing candidates, a hexokinase, was up-regulated during co-culturing with human immune system cells. CONCLUSION Genes encoding hexokinases and other proteins of interest may be subject to future manipulations to further refine understanding of Aspergillus pathogenicity factors.
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Affiliation(s)
- Kayla K Pennerman
- United States Department of Agriculture, Toxicology and Mycotoxin Research Unit, Athens, GA, 30605, USA.
| | - Guohua Yin
- Department of Plant Biology, Rutgers University, The State University of New Jersey, New Brunswick, NJ, 08901, USA
| | - Anthony E Glenn
- United States Department of Agriculture, Toxicology and Mycotoxin Research Unit, Athens, GA, 30605, USA
| | - Joan W Bennett
- Department of Plant Biology, Rutgers University, The State University of New Jersey, New Brunswick, NJ, 08901, USA
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Tomimoto K, Osafune Y, Kakizono D, Han J, Mukai N. Isolation methods of high glycosidase-producing mutants of Aspergillus luchuensis and its mutated genes. Biosci Biotechnol Biochem 2019; 84:198-207. [PMID: 31566090 DOI: 10.1080/09168451.2019.1671788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
High glycosidase-producing strains of Aspergillus luchuensis were isolated from 2-deoxyglucose (2-DG) resistant mutants. α-Amylase, exo-α-1,4-glucosidase, β-glucosidase and β-xylosidase activity in the mutants was ~3, ~2, ~4 and ~2.5 times higher than the parental strain RIB2604 on koji-making conditions, respectively. Citric acid production and mycelia growth of the mutants, however, approximately halved to that of the parent. Compared to the parent, the alcohol yield from rice and sweet potato shochu mash of the mutant increased ~5.7% and 3.0%, respectively. The mutant strains showed significantly low glucose assimilability despite the fructose one was almost normal, and they had a single missense or nonsense mutation in the glucokinase gene glkA. The recombinant strain that was introduced at one of the mutations, glkA Q300K, demonstrated similar but not identical phenotypes to the mutant strain. This result indicates that glkA Q300K is one of the major mutations in 2-DG resistant strains.
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Affiliation(s)
- Kazuya Tomimoto
- Brewing Microbiology Division, National Research Institute of Brewing, Higashi-hiroshima, Japan
| | - Yukio Osafune
- Brewing Technology Division, National Research Institute of Brewing, Higashi-hiroshima, Japan
| | - Dararat Kakizono
- Brewing Technology Division, National Research Institute of Brewing, Higashi-hiroshima, Japan
| | - Jinshun Han
- Brewing Technology Division, National Research Institute of Brewing, Higashi-hiroshima, Japan
| | - Nobuhiko Mukai
- Brewing Technology Division, National Research Institute of Brewing, Higashi-hiroshima, Japan
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12
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de Assis LJ, Manfiolli A, Mattos E, Fabri JHTM, Malavazi I, Jacobsen ID, Brock M, Cramer RA, Thammahong A, Hagiwara D, Ries LNA, Goldman GH. Protein Kinase A and High-Osmolarity Glycerol Response Pathways Cooperatively Control Cell Wall Carbohydrate Mobilization in Aspergillus fumigatus. mBio 2018; 9:e01952-18. [PMID: 30538182 PMCID: PMC6299480 DOI: 10.1128/mbio.01952-18] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 11/06/2018] [Indexed: 02/07/2023] Open
Abstract
Aspergillus fumigatus mitogen-activated protein kinases (MAPKs) are involved in maintaining the normal morphology of the cell wall and providing resistance against cell wall-damaging agents. Upon cell wall stress, cell wall-related sugars need to be synthesized from carbohydrate storage compounds. Here we show that this process is dependent on cAMP-dependent protein kinase A (PKA) activity and regulated by the high-osmolarity glycerol response (HOG) MAPKs SakA and MpkC. These protein kinases are necessary for normal accumulation/degradation of trehalose and glycogen, and the lack of these genes reduces glucose uptake and glycogen synthesis. Alterations in glycogen synthesis were observed for the sakA and mpkC deletion mutants, which also displayed alterations in carbohydrate exposure on the cell wall. Carbohydrate mobilization is controlled by SakA interaction with PkaC1 and PkaR, suggesting a putative mechanism where the PkaR regulatory subunit leaves the complex and releases the SakA-PkaC1 complex for activation of enzymes involved in carbohydrate mobilization. This work reveals the communication between the HOG and PKA pathways for carbohydrate mobilization for cell wall construction.IMPORTANCEAspergillus fumigatus is an opportunistic human pathogen causing allergic reactions or systemic infections such as invasive pulmonary aspergillosis, especially in immunocompromised patients. The fungal cell wall is the main component responsible for recognition by the immune system, due to the specific composition of polysaccharide carbohydrates exposed on the surface of the fungal cell wall called pathogen-associated molecular patterns (PAMPs). Key enzymes in the fungal cell wall biosynthesis are a good target for fungal drug development. This report elucidates the cooperation between the HOG and PKA pathways in the mobilization of carbohydrates for fungal cell wall biosynthesis. We suggest that the reduced mobilization of simple sugars causes defects in the structure of the fungal cell wall. In summary, we propose that SakA is important for PKA activity, therefore regulating the availability and mobilization of monosaccharides for fungal cell wall biosynthesis during cell wall damage and the osmotic stress response.
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Affiliation(s)
- Leandro José de Assis
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
| | - Adriana Manfiolli
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
| | - Eliciane Mattos
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
| | - João H T Marilhano Fabri
- Departamento de Genética e Evolução, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, São Paulo, Brazil
| | - Iran Malavazi
- Departamento de Genética e Evolução, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, São Paulo, Brazil
| | - Ilse D Jacobsen
- Research Group Microbial Immunology, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany
| | - Matthias Brock
- Fungal Genetics and Biology Group, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Robert A Cramer
- Geisel School of Medicine at Dartmouth, Department of Microbiology and Immunology, Hanover, New Hampshire, USA
| | - Arsa Thammahong
- Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Daisuke Hagiwara
- Faculty of Life and Environmental Sciences, University of Tsukuba, Ibaraki, Japan
| | | | - Gustavo Henrique Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
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Geib E, Baldeweg F, Doerfer M, Nett M, Brock M. Cross-Chemistry Leads to Product Diversity from Atromentin Synthetases in Aspergilli from Section Nigri. Cell Chem Biol 2018; 26:223-234.e6. [PMID: 30527997 DOI: 10.1016/j.chembiol.2018.10.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 09/07/2018] [Accepted: 10/22/2018] [Indexed: 01/06/2023]
Abstract
Non-ribosomal peptide synthetase (NRPS)-like enzymes catalyze the non-oxidative homodimerization of aromatic α-keto acids, but the exact reaction mechanism is unknown. The furanone-forming thioesterase domain of the Aspergillus terreus aspulvinone E synthetase MelA displays a predicted quinone-forming motif, whereby its catalytic triad contains an essential cysteine indicating an unusual thioester intermediate. To convert MelA into a quinone-forming atromentin synthetase its thioesterase domain was replaced with that from a Paxillus involutus or A. terreus atromentin synthetase. Phylogenetic proximity of donor and acceptor seems important, as only replacement with the A. terreus thioesterase was functional. Heterologous expression of atromentin synthetases in Aspergillus niger and Aspergillus oryzae revealed host-dependent product formation whereby cross-chemistry directed atromentin biosynthesis in A. niger toward atrofuranic acid. Screening of aspergilli from section Nigri identified an atromentin synthetase in Aspergillus brasiliensis that produced atrofuranic acid in the homologous host. Therefore, cross-chemistry on quinone cores appears common to section Nigri.
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Affiliation(s)
- Elena Geib
- Fungal Genetics and Biology, School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Florian Baldeweg
- Department of Pharmaceutical Microbiology at the Leibniz Institute for Natural Product Research and Infection Biology - Hans Knoell Institute, Friedrich-Schiller-University Jena, Adolf-Reichwein Straße 23a, 07745 Jena, Germany
| | - Maximilian Doerfer
- Department of Pharmaceutical Microbiology at the Leibniz Institute for Natural Product Research and Infection Biology - Hans Knoell Institute, Friedrich-Schiller-University Jena, Adolf-Reichwein Straße 23a, 07745 Jena, Germany
| | - Markus Nett
- Department of Biochemical and Chemical Engineering, TU Dortmund University, Emil-Figge-Straße 66, 44227 Dortmund, Germany
| | - Matthias Brock
- Fungal Genetics and Biology, School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
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The Aspergillus nidulans Pyruvate Dehydrogenase Kinases Are Essential To Integrate Carbon Source Metabolism. G3-GENES GENOMES GENETICS 2018; 8:2445-2463. [PMID: 29794164 PMCID: PMC6027865 DOI: 10.1534/g3.118.200411] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The pyruvate dehydrogenase complex (PDH), that converts pyruvate to acetyl-coA, is regulated by pyruvate dehydrogenase kinases (PDHK) and phosphatases (PDHP) that have been shown to be important for morphology, pathogenicity and carbon source utilization in different fungal species. The aim of this study was to investigate the role played by the three PDHKs PkpA, PkpB and PkpC in carbon source utilization in the reference filamentous fungus Aspergillus nidulans, in order to unravel regulatory mechanisms which could prove useful for fungal biotechnological and biomedical applications. PkpA and PkpB were shown to be mitochondrial whereas PkpC localized to the mitochondria in a carbon source-dependent manner. Only PkpA was shown to regulate PDH activity. In the presence of glucose, deletion of pkpA and pkpC resulted in reduced glucose utilization, which affected carbon catabolite repression (CCR) and hydrolytic enzyme secretion, due to de-regulated glycolysis and TCA cycle enzyme activities. Furthermore, PkpC was shown to be required for the correct metabolic utilization of cellulose and acetate. PkpC negatively regulated the activity of the glyoxylate cycle enzyme isocitrate lyase (ICL), required for acetate metabolism. In summary, this study identified PDHKs important for the regulation of central carbon metabolism in the presence of different carbon sources, with effects on the secretion of biotechnologically important enzymes and carbon source-related growth. This work demonstrates how central carbon metabolism can affect a variety of fungal traits and lays a basis for further investigation into these characteristics with potential interest for different applications.
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15
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Khosravi C, Battaglia E, Kun RS, Dalhuijsen S, Visser J, Aguilar-Pontes MV, Zhou M, Heyman HM, Kim YM, Baker SE, de Vries RP. Blocking hexose entry into glycolysis activates alternative metabolic conversion of these sugars and upregulates pentose metabolism in Aspergillus nidulans. BMC Genomics 2018; 19:214. [PMID: 29566661 PMCID: PMC5863803 DOI: 10.1186/s12864-018-4609-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 03/19/2018] [Indexed: 11/11/2022] Open
Abstract
Background Plant biomass is the most abundant carbon source for many fungal species. In the biobased industry fungi, are used to produce lignocellulolytic enzymes to degrade agricultural waste biomass. Here we evaluated if it would be possible to create an Aspergillus nidulans strain that releases, but does not metabolize hexoses from plant biomass. For this purpose, metabolic mutants were generated that were impaired in glycolysis, by using hexokinase (hxkA) and glucokinase (glkA) negative strains. To prevent repression of enzyme production due to the hexose accumulation, strains were generated that combined these mutations with a deletion in creA, the repressor involved in regulating preferential use of different carbon catabolic pathways. Results Phenotypic analysis revealed reduced growth for the hxkA1 glkA4 mutant on wheat bran. However, hexoses did not accumulate during growth of the mutants on wheat bran, suggesting that glucose metabolism is re-routed towards alternative carbon catabolic pathways. The creAΔ4 mutation in combination with preventing initial phosphorylation in glycolysis resulted in better growth than the hxkA/glkA mutant and an increased expression of pentose catabolic and pentose phosphate pathway genes. This indicates that the reduced ability to use hexoses as carbon sources created a shift towards the pentose fraction of wheat bran as a major carbon source to support growth. Conclusion Blocking the direct entry of hexoses to glycolysis activates alternative metabolic conversion of these sugars in A. nidulans during growth on plant biomass, but also upregulates conversion of other sugars, such as pentoses. Electronic supplementary material The online version of this article (10.1186/s12864-018-4609-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Claire Khosravi
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands
| | - Evy Battaglia
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands
| | - Roland S Kun
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands
| | - Sacha Dalhuijsen
- Microbiology, Utrecht University, Padualaan 8, 3584, CH, Utrecht, The Netherlands
| | - Jaap Visser
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands.,Fungal Genetics and Technology Consultancy, P.O. Box 396, 6700, AJ, Wageningen, The Netherlands
| | - María Victoria Aguilar-Pontes
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands
| | - Miaomiao Zhou
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands
| | - Heino M Heyman
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Young-Mo Kim
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Scott E Baker
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Ronald P de Vries
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands. .,Microbiology, Utrecht University, Padualaan 8, 3584, CH, Utrecht, The Netherlands.
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16
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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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17
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Adnan M, Zheng W, Islam W, Arif M, Abubakar YS, Wang Z, Lu G. Carbon Catabolite Repression in Filamentous Fungi. Int J Mol Sci 2017; 19:ijms19010048. [PMID: 29295552 PMCID: PMC5795998 DOI: 10.3390/ijms19010048] [Citation(s) in RCA: 122] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2017] [Revised: 12/13/2017] [Accepted: 12/20/2017] [Indexed: 12/18/2022] Open
Abstract
Carbon Catabolite Repression (CCR) has fascinated scientists and researchers around the globe for the past few decades. This important mechanism allows preferential utilization of an energy-efficient and readily available carbon source over relatively less easily accessible carbon sources. This mechanism helps microorganisms to obtain maximum amount of glucose in order to keep pace with their metabolism. Microorganisms assimilate glucose and highly favorable sugars before switching to less-favored sources of carbon such as organic acids and alcohols. In CCR of filamentous fungi, CreA acts as a transcription factor, which is regulated to some extent by ubiquitination. CreD-HulA ubiquitination ligase complex helps in CreA ubiquitination, while CreB-CreC deubiquitination (DUB) complex removes ubiquitin from CreA, which causes its activation. CCR of fungi also involves some very crucial elements such as Hexokinases, cAMP, Protein Kinase (PKA), Ras proteins, G protein-coupled receptor (GPCR), Adenylate cyclase, RcoA and SnfA. Thorough study of molecular mechanism of CCR is important for understanding growth, conidiation, virulence and survival of filamentous fungi. This review is a comprehensive revision of the regulation of CCR in filamentous fungi as well as an updated summary of key regulators, regulation of different CCR-dependent mechanisms and its impact on various physical characteristics of filamentous fungi.
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Affiliation(s)
- Muhammad Adnan
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
- Key Laboratory of Bio-Pesticides and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Wenhui Zheng
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
- Key Laboratory of Bio-Pesticides and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Waqar Islam
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Muhammad Arif
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Yakubu Saddeeq Abubakar
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
- Key Laboratory of Bio-Pesticides and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Zonghua Wang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
- Key Laboratory of Bio-Pesticides and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Guodong Lu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
- Key Laboratory of Bio-Pesticides and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
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18
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Geib E, Brock M. ATNT: an enhanced system for expression of polycistronic secondary metabolite gene clusters in Aspergillus niger. Fungal Biol Biotechnol 2017; 4:13. [PMID: 29270299 PMCID: PMC5735947 DOI: 10.1186/s40694-017-0042-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 12/12/2017] [Indexed: 11/16/2022] Open
Abstract
Background Fungi are treasure chests for yet unexplored natural products. However, exploitation of their real potential remains difficult as a significant proportion of biosynthetic gene clusters appears silent under standard laboratory conditions. Therefore, elucidation of novel products requires gene activation or heterologous expression. For heterologous gene expression, we previously developed an expression platform in Aspergillus niger that is based on the transcriptional regulator TerR and its target promoter PterA. Results In this study, we extended this system by regulating expression of terR by the doxycycline inducible Tet-on system. Reporter genes cloned under the control of the target promoter PterA remained silent in the absence of doxycycline, but were strongly expressed when doxycycline was added. Reporter quantification revealed that the coupled system results in about five times higher expression rates compared to gene expression under direct control of the Tet-on system. As production of secondary metabolites generally requires the expression of several biosynthetic genes, the suitability of the self-cleaving viral peptide sequence P2A was tested in this optimised expression system. P2A allowed polycistronic expression of genes required for Asp-melanin formation in combination with the gene coding for the red fluorescent protein tdTomato. Gene expression and Asp-melanin formation was prevented in the absence of doxycycline and strongly induced by addition of doxycycline. Fluorescence studies confirmed the correct subcellular localisation of the respective enzymes. Conclusion This tightly regulated but strongly inducible expression system enables high level production of secondary metabolites most likely even those with toxic potential. Furthermore, this system is compatible with polycistronic gene expression and, thus, suitable for the discovery of novel natural products. Electronic supplementary material The online version of this article (10.1186/s40694-017-0042-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Elena Geib
- Fungal Genetics and Biology, School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD UK
| | - Matthias Brock
- Fungal Genetics and Biology, School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD UK
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19
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Boral H, Metin B, Döğen A, Seyedmousavi S, Ilkit M. Overview of selected virulence attributes in Aspergillus fumigatus, Candida albicans, Cryptococcus neoformans, Trichophyton rubrum, and Exophiala dermatitidis. Fungal Genet Biol 2017; 111:92-107. [PMID: 29102684 DOI: 10.1016/j.fgb.2017.10.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 10/24/2017] [Accepted: 10/27/2017] [Indexed: 12/13/2022]
Abstract
The incidence of fungal diseases has been increasing since 1980, and is associated with excessive morbidity and mortality, particularly among immunosuppressed patients. Of the known 625 pathogenic fungal species, infections caused by the genera Aspergillus, Candida, Cryptococcus, and Trichophyton are responsible for more than 300 million estimated episodes of acute or chronic infections worldwide. In addition, a rather neglected group of opportunistic fungi known as black yeasts and their filamentous relatives cause a wide variety of recalcitrant infections in both immunocompetent and immunosuppressed hosts. This article provides an overview of selected virulence factors that are known to suppress host immunity and enhance the infectivity of these fungi.
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Affiliation(s)
- Hazal Boral
- Division of Mycology, Department of Microbiology, Faculty of Medicine, University of Çukurova, Adana, Turkey
| | - Banu Metin
- Department of Food Engineering, Faculty of Engineering and Natural Sciences, Istanbul Sabahattin Zaim University, Istanbul, Turkey
| | - Aylin Döğen
- Department of Pharmaceutical Microbiology, Faculty of Pharmacy, University of Mersin, Mersin, Turkey
| | - Seyedmojtaba Seyedmousavi
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands; Invasive Fungi Research Center, Mazandaran University of Medical Sciences, Sari, Iran; Center of Excellence for Infection Biology and Antimicrobial Pharmacology, Tehran, Iran
| | - Macit Ilkit
- Division of Mycology, Department of Microbiology, Faculty of Medicine, University of Çukurova, Adana, Turkey.
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20
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Wang J, Guo J, Wang S, Zeng Z, Zheng D, Yao X, Yu H, Ruan L. The global strategy employed by Xanthomonas oryzae pv. oryzae to conquer low-oxygen tension. J Proteomics 2017; 161:68-77. [PMID: 28412528 DOI: 10.1016/j.jprot.2017.04.006] [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: 08/04/2016] [Revised: 03/21/2017] [Accepted: 04/09/2017] [Indexed: 10/19/2022]
Abstract
Xanthomonas oryzae pv. oryzae (Xoo) is a notorious rice pathogen that causes bacterial leaf blight (BLB), a destructive rice disease. Low-oxygen tension in the xylem vessels of rice stresses Xoo during infection. In this study, differentially expressed proteins under normoxic and hypoxic conditions were identified using high-performance liquid chromatography (HPLC) coupled with LC-MS/MS to investigate the global effects of low oxygen environment on Xoo PXO99A. A statistically validated list of 187 (normoxia) and 140 (hypoxia) proteins with functional assignments was generated, allowing the reconstruction of central metabolic pathways. Ten proteins involved in aromatic amino acid biosynthesis, glycolysis, butanoate metabolism, propanoate metabolism and biological adhesion were significantly modulated under low-oxygen tension. The genes encoded by these proteins were in-frame deleted, and three of them were determined to be required for full virulence in Xoo. The contributions of these three genes to important virulence-associated functions, including extracellular polysaccharide, cell motility and antioxidative ability, are presented. BIOLOGICAL SIGNIFICANCE To study how Xanthomonas oryzae pv. oryzae (Xoo) conquers low-oxygen tension in the xylem of rice, we identified differentially expressed proteins under normoxic and hypoxia. We found 140 proteins that uniquely expressed under the hypoxia were involved in 33 metabolism pathways. We identified 3 proteins were required for full virulence in Xoo and related to the ability of extracellular polysaccharide, cell motility, and antioxidative. This study is helpful for broadening our knowledge of the metabolism processed of Xoo in the xylem of rice.
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Affiliation(s)
- Jianliang Wang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Jing Guo
- Agricultural Bioinformatics Key Laboratory of Hubei Province, College of Informatics, Huazhong Agricultural University, Wuhan 430070, China
| | - Shasha Wang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Zhiyong Zeng
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Dehong Zheng
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Xiaoyan Yao
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Haoquan Yu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Lifang Ruan
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
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21
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Central Role of the Trehalose Biosynthesis Pathway in the Pathogenesis of Human Fungal Infections: Opportunities and Challenges for Therapeutic Development. Microbiol Mol Biol Rev 2017; 81:81/2/e00053-16. [PMID: 28298477 DOI: 10.1128/mmbr.00053-16] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Invasive fungal infections cause significant morbidity and mortality in part due to a limited antifungal drug arsenal. One therapeutic challenge faced by clinicians is the significant host toxicity associated with antifungal drugs. Another challenge is the fungistatic mechanism of action of some drugs. Consequently, the identification of fungus-specific drug targets essential for fitness in vivo remains a significant goal of medical mycology research. The trehalose biosynthetic pathway is found in a wide variety of organisms, including human-pathogenic fungi, but not in humans. Genes encoding proteins involved in trehalose biosynthesis are mechanistically linked to the metabolism, cell wall homeostasis, stress responses, and virulence of Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus. While there are a number of pathways for trehalose production across the tree of life, the TPS/TPP (trehalose-6-phosphate synthase/trehalose-6-phosphate phosphatase) pathway is the canonical pathway found in human-pathogenic fungi. Importantly, data suggest that proteins involved in trehalose biosynthesis play other critical roles in fungal metabolism and in vivo fitness that remain to be fully elucidated. By further defining the biology and functions of trehalose and its biosynthetic pathway components in pathogenic fungi, an opportunity exists to leverage this pathway as a potent antifungal drug target. The goal of this review is to cover the known roles of this important molecule and its associated biosynthesis-encoding genes in the human-pathogenic fungi studied to date and to employ these data to critically assess the opportunities and challenges facing development of this pathway as a therapeutic target.
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22
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Matar KAO, Chen X, Chen D, Anjago WM, Norvienyeku J, Lin Y, Chen M, Wang Z, Ebbole DJ, Lu GD. WD40-repeat protein MoCreC is essential for carbon repression and is involved in conidiation, growth and pathogenicity of Magnaporthe oryzae. Curr Genet 2016; 63:685-696. [DOI: 10.1007/s00294-016-0668-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 11/20/2016] [Accepted: 11/25/2016] [Indexed: 01/13/2023]
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23
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Novodvorska M, Stratford M, Blythe MJ, Wilson R, Beniston RG, Archer DB. Metabolic activity in dormant conidia of Aspergillus niger and developmental changes during conidial outgrowth. Fungal Genet Biol 2016; 94:23-31. [PMID: 27378203 PMCID: PMC4981222 DOI: 10.1016/j.fgb.2016.07.002] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 06/21/2016] [Accepted: 07/01/2016] [Indexed: 01/15/2023]
Abstract
Resting conidia are demonstrated to be metabolically active. After triggering of conidial outgrowth fermentation occurs, followed by respiration. Sorbic acid inhibits O2 uptake and delays the onset of respiration.
The early stages of development of Aspergillus niger conidia during outgrowth were explored by combining genome-wide gene expression analysis (RNAseq), proteomics, Warburg manometry and uptake studies. Resting conidia suspended in water were demonstrated for the first time to be metabolically active as low levels of oxygen uptake and the generation of carbon dioxide were detected, suggesting that low-level respiratory metabolism occurs in conidia for maintenance. Upon triggering of spore germination, generation of CO2 increased dramatically. For a short period, which coincided with mobilisation of the intracellular polyol, trehalose, there was no increase in uptake of O2 indicating that trehalose was metabolised by fermentation. Data from genome-wide mRNA profiling showed the presence of transcripts associated with fermentative and respiratory metabolism in resting conidia. Following triggering of conidial outgrowth, there was a clear switch to respiration after 25 min, confirmed by cyanide inhibition. No effect of SHAM, salicylhydroxamic acid, on respiration suggests electron flow via cytochrome c oxidase. Glucose entry into spores was not detectable before 1 h after triggering germination. The impact of sorbic acid on germination was examined and we showed that it inhibits glucose uptake. O2 uptake was also inhibited, delaying the onset of respiration and extending the period of fermentation. In conclusion, we show that conidia suspended in water are not completely dormant and that conidial outgrowth involves fermentative metabolism that precedes respiration.
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Affiliation(s)
| | - Malcolm Stratford
- School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, UK; Mologic Ltd, Bedford Technology Park, Thurleigh, Bedfordshire MK44 2YA, UK.
| | - Martin J Blythe
- Deep Seq, Faculty of Medicine and Health Sciences, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2RD, UK.
| | - Raymond Wilson
- Deep Seq, Faculty of Medicine and Health Sciences, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2RD, UK.
| | - Richard G Beniston
- Biological Mass Spectrometry Facility biOMICS, University of Sheffield, Brook Hill Road, Sheffield S3 7HF, UK.
| | - David B Archer
- School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, UK.
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24
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Zhang L, Li B, Zhang Y, Jia X, Zhou M. Hexokinase plays a critical role in deoxynivalenol (DON) production and fungal development in Fusarium graminearum. MOLECULAR PLANT PATHOLOGY 2016; 17:16-28. [PMID: 25808544 PMCID: PMC6638496 DOI: 10.1111/mpp.12258] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Fusarium graminearum, the causal agent of Fusarium head blight, is a common pathogen on small grain cereals worldwide and produces various trichothecenes [deoxynivalenol (DON) is predominant] during infection. A previous study has revealed that DON production is positively correlated with the occurrence of carbendazim (MBC) resistance. Here, we identified and characterized two putative genes encoding hexokinase in F. graminearum (FgHXK1 and FgHXK2), which is a rate-limiting enzyme in DON biosynthesis. The expression level of hexokinase genes and the production of pyruvate, which is the precursor of DON, were up-regulated in the MBC-resistant strain, indicating that hexokinase genes might be involved in increased DON production. Phylogenetic and comparative analyses indicated that FgHXK1 was the predominant hexokinase gene. Gene disruption showed that ΔFgHXK1 severely affected DON production, indicating that FgHXK1 played a role in the regulation of DON biosynthesis. Morphological characterization showed that ΔFgHXK1 led to inhibited vegetative growth and conidiation. Sensitivity tests to MBC and various stresses indicated that both ΔFgHXK1 and ΔFgHXK2 mutants showed no significant difference from parental strains. Pathogencity assays showed that ΔFgHXK1 mutants lost virulence on wheat head and corn stigma; however, they showed no change in sexual reproduction. The FgHXK1-overexpressing transformants were obtained subsequently. Their pyruvate and DON production was confirmed to be increased, indicating that FgHXK1 positively regulated DON biosynthesis. Although additional defects appeared in overexpression mutants, MBC sensitivity showed no change. All of the results indicated that the transcriptional level of FgHXK1 regulated DON biosynthesis, but showed no direct relationship with MBC resistance.
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Affiliation(s)
- Leigang Zhang
- College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China
- State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing Agricultural University, Nanjing, 210095, China
- Institute of Agricultural Products Processing, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China
| | - Baicun Li
- College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China
- State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yu Zhang
- College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China
- State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing Agricultural University, Nanjing, 210095, China
| | - Xiaojing Jia
- College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China
- State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing Agricultural University, Nanjing, 210095, China
| | - Mingguo Zhou
- College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China
- State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing Agricultural University, Nanjing, 210095, China
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25
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Gressler M, Meyer F, Heine D, Hortschansky P, Hertweck C, Brock M. Phytotoxin production in Aspergillus terreus is regulated by independent environmental signals. eLife 2015; 4. [PMID: 26173180 PMCID: PMC4528345 DOI: 10.7554/elife.07861] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 07/13/2015] [Indexed: 01/09/2023] Open
Abstract
Secondary metabolites have a great potential as pharmaceuticals, but there are only a few examples where regulation of gene cluster expression has been correlated with ecological and physiological relevance for the producer. Here, signals, mediators, and biological effects of terrein production were studied in the fungus Aspergillus terreus to elucidate the contribution of terrein to ecological competition. Terrein causes fruit surface lesions and inhibits plant seed germination. Additionally, terrein is moderately antifungal and reduces ferric iron, thereby supporting growth of A. terreus under iron starvation. In accordance, the lack of nitrogen or iron or elevated methionine levels induced terrein production and was dependent on either the nitrogen response regulators AreA and AtfA or the iron response regulator HapX. Independent signal transduction allows complex sensing of the environment and, combined with its broad spectrum of biological activities, terrein provides a prominent example of adapted secondary metabolite production in response to environmental competition. DOI:http://dx.doi.org/10.7554/eLife.07861.001 Organisms produce a wide variety of small molecules called metabolites through the break down of food and other chemical reactions. Some of these molecules—known as primary metabolites—are required for growth, reproduction and other vital processes. Other molecules called secondary metabolites are not strictly required by the organism, but generally have other roles that may improve the individual’s ability to survive and reproduce. Fungi and other microbes produce a large variety of secondary metabolites, many of which are used as medicines to treat diseases in humans and other animals. For example, a molecule called lovastatin—which is produced by a fungus known as Aspergillus terreus—can reduce a human patient's risk of heart disease. However, it is not known what role many secondary metabolites play in the microbe that produced them. A. terreus lives in the soil, but it can also infect plants and animals. In addition to lovastatin, it also makes another secondary metabolite called terrein. A recent study identified the genes responsible for making terrein, and discovered that this molecule is harmful to plant cells and may help the fungus to colonize and thrive in the area immediately around plant roots, which is known as the rhizosphere. Here, Gressler et al. studied how terrein may help the fungus to cope with competitors in this environment. The experiments show that terrein increases the availability of iron and inhibits the growth of competing microbes. A shortage of iron or nitrogen-containing nutrients can stimulate the fungus to produce terrein, and elevated levels of a molecule called methionine have the same effect. These conditions are commonly found in the rhizosphere and further experiments identified several proteins in the fungus that are required for sensing them. Gressler et al.'s findings suggest that terrein helps to ensure that the fungus has sufficient nitrogen and iron to thrive in the rhizosphere. Also, this study confirms that the production of secondary metabolites in microbes can happen in response to elaborate cues from the environment, which may explain why only a limited number of secondary metabolites are produced by microbes when they are grown in the laboratory. Future studies will analyze other ways to activate the production of secondary metabolites outside of the microbe's normal environment, which may lead to the discovery of new important drugs. DOI:http://dx.doi.org/10.7554/eLife.07861.002
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Affiliation(s)
- Markus Gressler
- Microbial Biochemistry and Physiology, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany
| | - Florian Meyer
- Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany
| | - Daniel Heine
- Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany
| | - Peter Hortschansky
- Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany
| | - Christian Hertweck
- Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany
| | - Matthias Brock
- Institute for Microbiology, Friedrich Schiller University, Jena, Germany.,Fungal Genetics and Biology Group, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
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26
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Evidence of a New Intermediate Compound of the Chitin Biogenesis Found in a Marine-Derived Fungus. Appl Biochem Biotechnol 2014; 174:2426-34. [DOI: 10.1007/s12010-014-1180-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 08/15/2014] [Indexed: 01/07/2023]
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27
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Zaehle C, Gressler M, Shelest E, Geib E, Hertweck C, Brock M. Terrein biosynthesis in Aspergillus terreus and its impact on phytotoxicity. ACTA ACUST UNITED AC 2014; 21:719-31. [PMID: 24816227 DOI: 10.1016/j.chembiol.2014.03.010] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 03/19/2014] [Accepted: 03/26/2014] [Indexed: 12/18/2022]
Abstract
Terrein is a fungal metabolite with ecological, antimicrobial, antiproliferative, and antioxidative activities. Although it is produced by Aspergillus terreus as one of its major secondary metabolites, not much is known about its biosynthetic pathway. Here, we describe an unexpected discovery of the terrein biosynthesis gene locus made while we were looking for a PKS gene involved in production of conidia coloration pigments common for Aspergilli. The gene, ATEG_00145, here named terA, is essential for terrein biosynthesis and heterologous production of TerA in Aspergillus niger revealed an unusual plasticity in the products formed, yielding a mixture of 4-hydroxy-6-methylpyranone, orsellinic acid, and 6,7-dihydroxymellein. Biochemical and molecular genetic analyses indicate a low extension cycle specificity of TerA. Furthermore, 6-hydroxymellein was identified as a key intermediate in terrein biosynthesis. We find that terrein production is highly induced on plant-derived media, that terrein has phytotoxic activity on plant growth, and induces lesions on fruit surfaces.
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Affiliation(s)
- Christoph Zaehle
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Beutenbergstrasse 11a, 07745 Jena, Germany
| | - Markus Gressler
- Research Group Microbial Biochemistry and Physiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Beutenbergstrasse 11a, 07745 Jena, Germany
| | - Ekaterina Shelest
- Research Group Systems Biology/Bioinformatics, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Beutenbergstrasse 11a, 07743 Jena, Germany
| | - Elena Geib
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Beutenbergstrasse 11a, 07745 Jena, Germany
| | - Christian Hertweck
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Beutenbergstrasse 11a, 07745 Jena, Germany.
| | - Matthias Brock
- Research Group Microbial Biochemistry and Physiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Beutenbergstrasse 11a, 07745 Jena, Germany; Institute for Microbiology, Friedrich-Schiller University, 07743 Jena, Germany.
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Structural features of sugars that trigger or support conidial germination in the filamentous fungus Aspergillus niger. Appl Environ Microbiol 2013; 79:6924-31. [PMID: 23995938 DOI: 10.1128/aem.02061-13] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The asexual spores (conidia) of Aspergillus niger germinate to produce hyphae under appropriate conditions. Germination is initiated by conidial swelling and mobilization of internal carbon and energy stores, followed by polarization and emergence of a hyphal germ tube. The effects of different pyranose sugars, all analogues of d-glucose, on the germination of A. niger conidia were explored, and we define germination as the transition from a dormant conidium into a germling. Within germination, we distinguish two distinct stages, the initial swelling of the conidium and subsequent polarized growth. The stage of conidial swelling requires a germination trigger, which we define as a compound that is sensed by the conidium and which leads to catabolism of d-trehalose and isotropic growth. Sugars that triggered germination and outgrowth included d-glucose, d-mannose, and d-xylose. Sugars that triggered germination but did not support subsequent outgrowth included d-tagatose, d-lyxose, and 2-deoxy-d-glucose. Nontriggering sugars included d-galactose, l-glucose, and d-arabinose. Certain nontriggering sugars, including d-galactose, supported outgrowth if added in the presence of a complementary triggering sugar. This division of functions indicates that sugars are involved in two separate events in germination, triggering and subsequent outgrowth, and the structural features of sugars that support each, both, or none of these events are discussed. We also present data on the uptake of sugars during the germination process and discuss possible mechanisms of triggering in the absence of apparent sugar uptake during the initial swelling of conidia.
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29
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Boettger D, Bergmann H, Kuehn B, Shelest E, Hertweck C. Evolutionary Imprint of Catalytic Domains in Fungal PKS-NRPS Hybrids. Chembiochem 2012; 13:2363-73. [DOI: 10.1002/cbic.201200449] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2012] [Indexed: 12/13/2022]
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Fernandez J, Wright JD, Hartline D, Quispe CF, Madayiputhiya N, Wilson RA. Principles of carbon catabolite repression in the rice blast fungus: Tps1, Nmr1-3, and a MATE-family pump regulate glucose metabolism during infection. PLoS Genet 2012; 8:e1002673. [PMID: 22570632 PMCID: PMC3342947 DOI: 10.1371/journal.pgen.1002673] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Accepted: 03/12/2012] [Indexed: 12/14/2022] Open
Abstract
Understanding the genetic pathways that regulate how pathogenic fungi respond to their environment is paramount to developing effective mitigation strategies against disease. Carbon catabolite repression (CCR) is a global regulatory mechanism found in a wide range of microbial organisms that ensures the preferential utilization of glucose over less favourable carbon sources, but little is known about the components of CCR in filamentous fungi. Here we report three new mediators of CCR in the devastating rice blast fungus Magnaporthe oryzae: the sugar sensor Tps1, the Nmr1-3 inhibitor proteins, and the multidrug and toxin extrusion (MATE)-family pump, Mdt1. Using simple plate tests coupled with transcriptional analysis, we show that Tps1, in response to glucose-6-phosphate sensing, triggers CCR via the inactivation of Nmr1-3. In addition, by dissecting the CCR pathway using Agrobacterium tumefaciens-mediated mutagenesis, we also show that Mdt1 is an additional and previously unknown regulator of glucose metabolism. Mdt1 regulates glucose assimilation downstream of Tps1 and is necessary for nutrient utilization, sporulation, and pathogenicity. This is the first functional characterization of a MATE-family protein in filamentous fungi and the first description of a MATE protein in genetic regulation or plant pathogenicity. Perturbing CCR in Δtps1 and MDT1 disruption strains thus results in physiological defects that impact pathogenesis, possibly through the early expression of cell wall-degrading enzymes. Taken together, the importance of discovering three new regulators of carbon metabolism lies in understanding how M. oryzae and other pathogenic fungi respond to nutrient availability and control development during infection.
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Affiliation(s)
- Jessie Fernandez
- Department of Plant Pathology, University of Nebraska–Lincoln, Lincoln, Nebraska, United States of America
| | - Janet D. Wright
- Department of Plant Pathology, University of Nebraska–Lincoln, Lincoln, Nebraska, United States of America
| | - David Hartline
- Department of Plant Pathology, University of Nebraska–Lincoln, Lincoln, Nebraska, United States of America
| | - Cristian F. Quispe
- Department of Plant Pathology, University of Nebraska–Lincoln, Lincoln, Nebraska, United States of America
| | - Nandakumar Madayiputhiya
- Proteomic and Metabolomic Core Facility, Redox Biology Center, Department of Biochemistry, University of Nebraska–Lincoln, Lincoln, Nebraska, United States of America
| | - Richard A. Wilson
- Department of Plant Pathology, University of Nebraska–Lincoln, Lincoln, Nebraska, United States of America
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31
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DIGE enables the detection of a putative serum biomarker of fungal origin in a mouse model of invasive aspergillosis. J Proteomics 2012; 75:2536-49. [DOI: 10.1016/j.jprot.2012.01.040] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2011] [Revised: 01/27/2012] [Accepted: 01/30/2012] [Indexed: 11/20/2022]
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32
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Fuller KK, Rhodes JC. Protein kinase A and fungal virulence: a sinister side to a conserved nutrient sensing pathway. Virulence 2012; 3:109-21. [PMID: 22460637 PMCID: PMC3396691 DOI: 10.4161/viru.19396] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Diverse fungal species are the cause of devastating agricultural and human diseases. As successful pathogenesis is dependent upon the ability of the fungus to adapt to the nutritional and chemical environment of the host, the understanding of signaling pathways required for such adaptation will provide insights into the virulence of these pathogens and the potential identification of novel targets for antifungal intervention. The cAMP-PKA signaling pathway is well conserved across eukaryotes. In the nonpathogenic yeast, S. cerevisiae, PKA is activated in response to extracellular nutrients and subsequently regulates metabolism and growth. Importantly, this pathway is also a regulator of pathogenesis, as defects in PKA signaling lead to an attenuation of virulence in diverse plant and human pathogenic fungi. This review will compare and contrast PKA signaling in S. cerevisiae vs. various pathogenic species and provide a framework for the role of this pathway in regulating fungal virulence.
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Affiliation(s)
- Kevin K Fuller
- Department of Pathology, University of Cincinnati College of Medicine, Cincinnati, OH, USA.
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Barker BM, Kroll K, Vödisch M, Mazurie A, Kniemeyer O, Cramer RA. Transcriptomic and proteomic analyses of the Aspergillus fumigatus hypoxia response using an oxygen-controlled fermenter. BMC Genomics 2012; 13:62. [PMID: 22309491 PMCID: PMC3293747 DOI: 10.1186/1471-2164-13-62] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Accepted: 02/06/2012] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Aspergillus fumigatus is a mold responsible for the majority of cases of aspergillosis in humans. To survive in the human body, A. fumigatus must adapt to microenvironments that are often characterized by low nutrient and oxygen availability. Recent research suggests that the ability of A. fumigatus and other pathogenic fungi to adapt to hypoxia contributes to their virulence. However, molecular mechanisms of A. fumigatus hypoxia adaptation are poorly understood. Thus, to better understand how A. fumigatus adapts to hypoxic microenvironments found in vivo during human fungal pathogenesis, the dynamic changes of the fungal transcriptome and proteome in hypoxia were investigated over a period of 24 hours utilizing an oxygen-controlled fermenter system. RESULTS Significant increases in transcripts associated with iron and sterol metabolism, the cell wall, the GABA shunt, and transcriptional regulators were observed in response to hypoxia. A concomitant reduction in transcripts was observed with ribosome and terpenoid backbone biosynthesis, TCA cycle, amino acid metabolism and RNA degradation. Analysis of changes in transcription factor mRNA abundance shows that hypoxia induces significant positive and negative changes that may be important for regulating the hypoxia response in this pathogenic mold. Growth in hypoxia resulted in changes in the protein levels of several glycolytic enzymes, but these changes were not always reflected by the corresponding transcriptional profiling data. However, a good correlation overall (R(2) = 0.2, p < 0.05) existed between the transcriptomic and proteomics datasets for all time points. The lack of correlation between some transcript levels and their subsequent protein levels suggests another regulatory layer of the hypoxia response in A. fumigatus. CONCLUSIONS Taken together, our data suggest a robust cellular response that is likely regulated both at the transcriptional and post-transcriptional level in response to hypoxia by the human pathogenic mold A. fumigatus. As with other pathogenic fungi, the induction of glycolysis and transcriptional down-regulation of the TCA cycle and oxidative phosphorylation appear to major components of the hypoxia response in this pathogenic mold. In addition, a significant induction of the transcripts involved in ergosterol biosynthesis is consistent with previous observations in the pathogenic yeasts Candida albicans and Cryptococcus neoformans indicating conservation of this response to hypoxia in pathogenic fungi. Because ergosterol biosynthesis enzymes also require iron as a co-factor, the increase in iron uptake transcripts is consistent with an increased need for iron under hypoxia. However, unlike C. albicans and C. neoformans, the GABA shunt appears to play an important role in reducing NADH levels in response to hypoxia in A. fumigatus and it will be intriguing to determine whether this is critical for fungal virulence. Overall, regulatory mechanisms of the A. fumigatus hypoxia response appear to involve both transcriptional and post-transcriptional control of transcript and protein levels and thus provide candidate genes for future analysis of their role in hypoxia adaptation and fungal virulence.
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Affiliation(s)
- Bridget M Barker
- Department of Immunology and Infectious Disease, Montana State University, Bozeman, MT, USA
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Slesiona S, Gressler M, Mihlan M, Zaehle C, Schaller M, Barz D, Hube B, Jacobsen ID, Brock M. Persistence versus escape: Aspergillus terreus and Aspergillus fumigatus employ different strategies during interactions with macrophages. PLoS One 2012; 7:e31223. [PMID: 22319619 PMCID: PMC3272006 DOI: 10.1371/journal.pone.0031223] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2011] [Accepted: 01/04/2012] [Indexed: 12/02/2022] Open
Abstract
Invasive bronchopulmonary aspergillosis (IBPA) is a life-threatening disease in immunocompromised patients. Although Aspergillus terreus is frequently found in the environment, A. fumigatus is by far the main cause of IBPA. However, once A. terreus establishes infection in the host, disease is as fatal as A. fumigatus infections. Thus, we hypothesized that the initial steps of disease establishment might be fundamentally different between these two species. Since alveolar macrophages represent one of the first phagocytes facing inhaled conidia, we compared the interaction of A. terreus and A. fumigatus conidia with alveolar macrophages. A. terreus conidia were phagocytosed more rapidly than A. fumigatus conidia, possibly due to higher exposure of β-1,3-glucan and galactomannan on the surface. In agreement, blocking of dectin-1 and mannose receptors significantly reduced phagocytosis of A. terreus, but had only a moderate effect on phagocytosis of A. fumigatus. Once phagocytosed, and in contrast to A. fumigatus, A. terreus did not inhibit acidification of phagolysosomes, but remained viable without signs of germination both in vitro and in immunocompetent mice. The inability of A. terreus to germinate and pierce macrophages resulted in significantly lower cytotoxicity compared to A. fumigatus. Blocking phagolysosome acidification by the v-ATPase inhibitor bafilomycin increased A. terreus germination rates and cytotoxicity. Recombinant expression of the A. nidulans wA naphthopyrone synthase, a homologue of A. fumigatus PksP, inhibited phagolysosome acidification and resulted in increased germination, macrophage damage and virulence in corticosteroid-treated mice. In summary, we show that A. terreus and A. fumigatus have evolved significantly different strategies to survive the attack of host immune cells. While A. fumigatus prevents phagocytosis and phagolysosome acidification and escapes from macrophages by germination, A. terreus is rapidly phagocytosed, but conidia show long-term persistence in macrophages even in immunocompetent hosts.
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Affiliation(s)
- Silvia Slesiona
- Microbial Biochemistry and Physiology, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany
- Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany
| | - Markus Gressler
- Microbial Biochemistry and Physiology, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany
| | - Michael Mihlan
- Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany
| | - Christoph Zaehle
- Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany
| | - Martin Schaller
- Department of Dermatology, Eberhard-Karls-University, Tübingen, Germany
| | - Dagmar Barz
- Institute for Transfusion Medicine, University Hospital, Jena, Germany
| | - Bernhard Hube
- Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany
- Friedrich Schiller University, Jena, Germany
| | - Ilse D. Jacobsen
- Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany
- * E-mail: (IDJ); (MB)
| | - Matthias Brock
- Microbial Biochemistry and Physiology, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany
- * E-mail: (IDJ); (MB)
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Kim H, Smith JE, Ridenour JB, Woloshuk CP, Bluhm BH. HXK1 regulates carbon catabolism, sporulation, fumonisin B₁ production and pathogenesis in Fusarium verticillioides. MICROBIOLOGY-SGM 2011; 157:2658-2669. [PMID: 21719539 DOI: 10.1099/mic.0.052506-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In Fusarium verticillioides, a ubiquitous pathogen of maize, virulence and mycotoxigenesis are regulated in response to the types and amounts of carbohydrates present in maize kernels. In this study, we investigated the role of a putative hexokinase-encoding gene (HXK1) in growth, development and pathogenesis. A deletion mutant (Δhxk1) of HXK1 was not able to grow when supplied with fructose as the sole carbon source, and growth was impaired when glucose, sucrose or maltotriose was provided. Additionally, the Δhxk1 mutant produced unusual swollen hyphae when provided with fructose, but not glucose, as the sole carbon source. Moreover, the Δhxk1 mutant was impaired in fructose uptake, although glucose uptake was unaffected. On maize kernels, the Δhxk1 mutant was substantially less virulent than the wild-type, but virulence on maize stalks was not impaired, possibly indicating a metabolic response to tissue-specific differences in plant carbohydrate content. Finally, disruption of HXK1 had a pronounced effect on fungal metabolites produced during colonization of maize kernels; the Δhxk1 mutant produced approximately 50 % less trehalose and 80 % less fumonisin B₁ (FB₁) than the wild-type. The reduction in trehalose biosynthesis likely explains observations of increased sensitivity to osmotic stress in the Δhxk1 mutant. In summary, this study links early events in carbohydrate sensing and glycolysis to virulence and secondary metabolism in F. verticillioides, and thus provides a new foothold from which the genetic regulatory networks that underlie pathogenesis and mycotoxigenesis can be unravelled and defined.
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Affiliation(s)
- Hun Kim
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA.,Department of Plant Pathology, University of Arkansas, Fayetteville, AR 72701, USA
| | - Jonathon E Smith
- Department of Plant Pathology, University of Arkansas, Fayetteville, AR 72701, USA
| | - John B Ridenour
- Department of Plant Pathology, University of Arkansas, Fayetteville, AR 72701, USA
| | - Charles P Woloshuk
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA
| | - Burton H Bluhm
- Department of Plant Pathology, University of Arkansas, Fayetteville, AR 72701, USA
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Müller S, Fleck CB, Wilson D, Hummert C, Hube B, Brock M. Gene acquisition, duplication and metabolic specification: the evolution of fungal methylisocitrate lyases. Environ Microbiol 2011; 13:1534-48. [PMID: 21453403 DOI: 10.1111/j.1462-2920.2011.02458.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Gene duplication represents an evolutionary mechanism for expanding metabolic potential. Here we analysed the evolutionary relatedness of isocitrate and methylisocitrate lyases, which are key enzymes of the glyoxylate and methylcitrate cycle respectively. Phylogenetic analyses imply that ancient eukaryotes acquired an isocitrate lyase gene from a prokaryotic source, but it was lost in some eukaryotic lineages. However, protists, oomycetes and most fungi maintained this gene and successfully integrated the corresponding enzyme into the glyoxylate cycle. A second gene, encoding a highly related enzyme, is present in fungi, but absent from other eukaryotes. This methylisocitrate lyase is specifically involved in propionyl-CoA degradation via the methylcitrate cycle. Although bacteria possess methylisocitrate lyases with a structural fold similar to that of isocitrate lyases, their sequence identity to fungal methylisocitrate lyases is low. Phylogenetic analyses imply that fungal methylisocitrate lyases arose from gene duplication of an ancient isocitrate lyase gene from the basidiomycete lineage. Mutagenesis of active-site residues of a bacterial and fungal isocitrate lyase, which have been predicted to direct the substrate specificity of iso- and methylisocitrate lyases, experimentally confirmed the possibility of direct evolution of methylisocitrate lyases from isocitrate lyases. Thus, gene duplication has increased the metabolic capacity of fungi.
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Affiliation(s)
- Sebastian Müller
- Leibniz Institute for Natural Product Research and Infection Biology e.V., -Hans Knoell Institute-, Jena, Germany
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Multifactorial induction of an orphan PKS-NRPS gene cluster in Aspergillus terreus. ACTA ACUST UNITED AC 2011; 18:198-209. [PMID: 21236704 DOI: 10.1016/j.chembiol.2010.12.011] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Revised: 11/16/2010] [Accepted: 12/13/2010] [Indexed: 12/26/2022]
Abstract
Mining the genome of the pathogenic fungus Aspergillus terreus revealed the presence of an orphan polyketide-nonribosomal-peptide synthetase (PKS-NRPS) gene cluster. Induced expression of the transcriptional activator gene adjacent to the PKS-NRPS gene was not sufficient for the activation of the silent pathway. Monitoring gene expression, metabolic profiling, and using a lacZ reporter strain allowed for the systematic investigation of physiological conditions that eventually led to the discovery of isoflavipucine and dihydroisoflavipucine. Phytotoxin formation is only activated in the presence of certain amino acids, stimulated at alkaline pH, but strictly repressed in the presence of glucose. Global carbon catabolite repression by CreA cannot be abolished by positive-acting factors such as PacC and overrides the pathway activator. Gene inactivation and stable isotope labeling experiments unveiled the molecular basis for flavipucine/fruit rot toxin biosynthesis.
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38
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Fuller KK, Richie DL, Feng X, Krishnan K, Stephens TJ, Wikenheiser-Brokamp KA, Askew DS, Rhodes JC. Divergent Protein Kinase A isoforms co-ordinately regulate conidial germination, carbohydrate metabolism and virulence in Aspergillus fumigatus. Mol Microbiol 2011; 79:1045-62. [PMID: 21210869 DOI: 10.1111/j.1365-2958.2010.07509.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The genome of Aspergillus fumigatus encodes two isoforms of the catalytic subunit of the cAMP-dependent Protein Kinase (PKA). Although deletion of the class I isoform, pkaC1, leads to an attenuation of virulence, the function of the class II subunit, PkaC2, was previously uninvestigated. In this report, we demonstrate that both isoforms act in concert to support various physiologic processes that promote the virulence of this pathogen. Whereas pkaC1 and pkaC2 single-deletion mutants display wild-type conidial germination, a double-deletion mutant is delayed in germination in response to environmental nutrients. Furthermore, PkaC1 and PkaC2 interact to positively regulate flux through the carbohydrate catabolic pathway and, consequently, the ΔpkaC1ΔpkaC2 mutant is unable to grow on low glucose concentrations. Importantly, the reduced germinative capacity and inability to utilize glucose observed for the ΔpkaC1ΔpkaC2 strain correlated with an inability of the mutant to establish infection in a murine model. Conversely, overexpression of pkaC2 both promotes the in vitro growth on glucose, and restores the fungal burden and mortality associated with the ΔpkaC1 to that of the wild-type organism. Taken together, these data demonstrate the functional capacity of pkaC2 and emphasize the importance of PKA-mediated metabolic control in the pathogenic potential of A. fumigatus.
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Affiliation(s)
- Kevin K Fuller
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267-0529, USA
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