1
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Sun M, Dai P, Cao Z, Dong J. Purine metabolism in plant pathogenic fungi. Front Microbiol 2024; 15:1352354. [PMID: 38384269 PMCID: PMC10879430 DOI: 10.3389/fmicb.2024.1352354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 01/29/2024] [Indexed: 02/23/2024] Open
Abstract
In eukaryotic cells, purine metabolism is the way to the production of deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) and plays key roles in various biological processes. Purine metabolism mainly consists of de novo, salvage, and catabolic pathways, and some components of these pathways have been characterized in some plant pathogenic fungi, such as the rice blast fungus Magnaporthe oryzae and wheat head blight fungus Fusarium graminearum. The enzymatic steps of the de novo pathway are well-conserved in plant pathogenic fungi and play crucial roles in fungal growth and development. Blocking this pathway inhibits the formation of penetration structures and invasive growth, making it essential for plant infection by pathogenic fungi. The salvage pathway is likely indispensable but requires exogenous purines, implying that purine transporters are functional in these fungi. The catabolic pathway balances purine nucleotides and may have a conserved stage-specific role in pathogenic fungi. The significant difference of the catabolic pathway in planta and in vitro lead us to further explore and identify the key genes specifically regulating pathogenicity in purine metabolic pathway. In this review, we summarized recent advances in the studies of purine metabolism, focusing on the regulation of pathogenesis and growth in plant pathogenic fungi.
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Affiliation(s)
- Manli Sun
- State Key Laboratory of North China Crop Improvement and Regulation/Key Laboratory of Hebei Province for Plant Physiology and Molecular Pathology/College of Plant Protection, Hebei Agricultural University, Baoding, Hebei, China
| | | | | | - Jingao Dong
- State Key Laboratory of North China Crop Improvement and Regulation/Key Laboratory of Hebei Province for Plant Physiology and Molecular Pathology/College of Plant Protection, Hebei Agricultural University, Baoding, Hebei, China
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2
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Wizrah MS, Chua SM, Luo Z, Manik MK, Pan M, Whyte JM, Robertson AA, Kappler U, Kobe B, Fraser JA. AICAR transformylase/IMP cyclohydrolase (ATIC) is essential for de novo purine biosynthesis and infection by Cryptococcus neoformans. J Biol Chem 2022; 298:102453. [PMID: 36063996 PMCID: PMC9525906 DOI: 10.1016/j.jbc.2022.102453] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 08/25/2022] [Accepted: 08/26/2022] [Indexed: 01/27/2023] Open
Abstract
The fungal pathogen Cryptococcus neoformans is a leading cause of meningoencephalitis in the immunocompromised. As current antifungal treatments are toxic to the host, costly, limited in their efficacy, and associated with drug resistance, there is an urgent need to identify vulnerabilities in fungal physiology to accelerate antifungal discovery efforts. Rational drug design was pioneered in de novo purine biosynthesis as the end products of the pathway, ATP and GTP, are essential for replication, transcription, and energy metabolism, and the same rationale applies when considering the pathway as an antifungal target. Here, we describe the identification and characterization of C. neoformans 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) transformylase/5'-inosine monophosphate cyclohydrolase (ATIC), a bifunctional enzyme that catalyzes the final two enzymatic steps in the formation of the first purine base inosine monophosphate. We demonstrate that mutants lacking the ATIC-encoding ADE16 gene are adenine and histidine auxotrophs that are unable to establish an infection in a murine model of virulence. In addition, our assays employing recombinantly expressed and purified C. neoformans ATIC enzyme revealed Km values for its substrates AICAR and 5-formyl-AICAR are 8-fold and 20-fold higher, respectively, than in the human ortholog. Subsequently, we performed crystallographic studies that enabled the determination of the first fungal ATIC protein structure, revealing a key serine-to-tyrosine substitution in the active site, which has the potential to assist the design of fungus-specific inhibitors. Overall, our results validate ATIC as a promising antifungal drug target.
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Affiliation(s)
- Maha S.I. Wizrah
- Australian Infectious Diseases Research Centre, University of Queensland, St Lucia, Queensland, Australia,School of Chemistry & Molecular Biosciences, University of Queensland, St Lucia, Queensland, Australia
| | - Sheena M.H. Chua
- Australian Infectious Diseases Research Centre, University of Queensland, St Lucia, Queensland, Australia,School of Chemistry & Molecular Biosciences, University of Queensland, St Lucia, Queensland, Australia
| | - Zhenyao Luo
- School of Chemistry & Molecular Biosciences, University of Queensland, St Lucia, Queensland, Australia,Institute for Molecular Bioscience, University of Queensland, St Lucia, Queensland, Australia
| | - Mohammad K. Manik
- Australian Infectious Diseases Research Centre, University of Queensland, St Lucia, Queensland, Australia,School of Chemistry & Molecular Biosciences, University of Queensland, St Lucia, Queensland, Australia,Institute for Molecular Bioscience, University of Queensland, St Lucia, Queensland, Australia
| | - Mengqi Pan
- Australian Infectious Diseases Research Centre, University of Queensland, St Lucia, Queensland, Australia,School of Chemistry & Molecular Biosciences, University of Queensland, St Lucia, Queensland, Australia,Institute for Molecular Bioscience, University of Queensland, St Lucia, Queensland, Australia
| | - Jessica M.L. Whyte
- Australian Infectious Diseases Research Centre, University of Queensland, St Lucia, Queensland, Australia,School of Chemistry & Molecular Biosciences, University of Queensland, St Lucia, Queensland, Australia
| | - Avril A.B. Robertson
- Australian Infectious Diseases Research Centre, University of Queensland, St Lucia, Queensland, Australia,School of Chemistry & Molecular Biosciences, University of Queensland, St Lucia, Queensland, Australia,Institute for Molecular Bioscience, University of Queensland, St Lucia, Queensland, Australia
| | - Ulrike Kappler
- Australian Infectious Diseases Research Centre, University of Queensland, St Lucia, Queensland, Australia,School of Chemistry & Molecular Biosciences, University of Queensland, St Lucia, Queensland, Australia
| | - Bostjan Kobe
- Australian Infectious Diseases Research Centre, University of Queensland, St Lucia, Queensland, Australia,School of Chemistry & Molecular Biosciences, University of Queensland, St Lucia, Queensland, Australia,Institute for Molecular Bioscience, University of Queensland, St Lucia, Queensland, Australia
| | - James A. Fraser
- Australian Infectious Diseases Research Centre, University of Queensland, St Lucia, Queensland, Australia,School of Chemistry & Molecular Biosciences, University of Queensland, St Lucia, Queensland, Australia,For correspondence: James A. Fraser
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Wolff DW, Bianchi-Smiraglia A, Nikiforov MA. Compartmentalization and regulation of GTP in control of cellular phenotypes. Trends Mol Med 2022; 28:758-769. [PMID: 35718686 PMCID: PMC9420775 DOI: 10.1016/j.molmed.2022.05.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 05/26/2022] [Accepted: 05/27/2022] [Indexed: 10/18/2022]
Abstract
Genetic or pharmacological inhibition of enzymes involved in GTP biosynthesis has substantial biological effects, underlining the need to better understand the function of GTP levels in regulation of cellular processes and the significance of targeting GTP biosynthesis enzymes for therapeutic intervention. Our current understanding of spatiotemporal regulation of GTP metabolism and its role in physiological and pathological cellular processes is far from complete. Novel methodologies such as genetically encoded sensors of free GTP offered insights into intracellular distribution and function of GTP molecules. In the current Review, we provide analysis of recent discoveries in the field of GTP metabolism and evaluate the key enzymes as molecular targets.
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Affiliation(s)
- David W Wolff
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC 27708, USA.
| | - Anna Bianchi-Smiraglia
- Department of Cell Stress Biology, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14203, USA
| | - Mikhail A Nikiforov
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC 27708, USA; Department of Pathology, Duke University School of Medicine, Durham, NC 27710, USA.
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4
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Aron O, Otieno FJ, Tijjani I, Yang Z, Xu H, Weng S, Guo J, Lu S, Wang Z, Tang W. De novo purine nucleotide biosynthesis mediated by MoAde4 is required for conidiation, host colonization and pathogenicity in Magnaporthe oryzae. Appl Microbiol Biotechnol 2022; 106:5587-5602. [PMID: 35918446 DOI: 10.1007/s00253-022-12100-z] [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: 11/11/2021] [Revised: 07/18/2022] [Accepted: 07/21/2022] [Indexed: 11/02/2022]
Abstract
Amidophosphoribosyltransferase catalyzes the conversion of 5-phosphoribosyl-1-pyrophosphate into 5-phosphoribosyl-1-amine in the de novo purine biosynthetic pathway. Herein, we identified and characterized the functions of MoAde4, an orthologue of yeast Ade4 in Magnaporthe oryzae. MoAde4 is a 537-amino acid protein containing GATase_6 and pribosyltran domains. MoADE4 transcripts were highly expressed during the conidiation, early-infection, and late-infection stages of the fungus. Disruption of the MoADE4 gene resulted in ΔMoade4 exhibiting adenine, adenosine, and hypoxanthine auxotrophy on minimal medium. Conidia quantification assays showed that sporulation was significantly reduced in the ΔMoade4 mutant. The conidia of ΔMoade4 could still form appressoria but mostly failed to penetrate the rice cuticle. Pathogenicity tests showed that ΔMoade4 was completely nonpathogenic on rice and barley leaves, which was attributed to restricted infectious hyphal growth within the primary cells. The ΔMoade4 mutant was defective in the induction of strong host immunity. Exogenous adenine partially rescued conidiation, infectious hyphal growth, and the pathogenicity defects of the ΔMoade4 mutant on barley and rice leaves. Taken together, our results demonstrated that purine nucleotide biosynthesis orchestrated by MoAde4 is required for fungal development and pathogenicity in M. oryzae. These findings therefore act as a suitable target for antifungal development against recalcitrant plant fungal pathogens. KEY POINTS: • MoAde4 is crucial for de novo purine nucleotide biosynthesis. • MoAde4 is pivotal for conidiogenesis and appressorium development of M. oryzae. • MoAde4 is involoved in the pathogenicity of M. oryzae.
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Affiliation(s)
- Osakina Aron
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Frankine Jagero Otieno
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Ibrahim Tijjani
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Zifeng Yang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Huxiao Xu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Shuning Weng
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Jiayuan Guo
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Songmao Lu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Zonghua Wang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou, 350002, China. .,Marine and Agricultural Biotechnology Laboratory, Institute of Oceanography, Minjiang University, Fuzhou, 350108, China.
| | - Wei Tang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou, 350002, China. .,Fujian Key Laboratory for Monitoring and Integrated Management of Crop Pests, Fuzhou, 350013, China.
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5
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Nguyen S, Jovcevski B, Pukala TL, Bruning JB. Structural insights into the antifungal drug target guanosine monophosphate synthase from Aspergillus fumigatus. ACTA CRYSTALLOGRAPHICA SECTION D STRUCTURAL BIOLOGY 2022; 78:248-259. [DOI: 10.1107/s2059798321012031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 11/11/2021] [Indexed: 11/10/2022]
Abstract
Purine biosynthesis is a fundamental cellular process that sustains life by maintaining the intracellular pool of purines for DNA/RNA synthesis and signal transduction. As an integral determinant of fungal survival and virulence, the enzymes in this metabolic pathway have been pursued as potential antifungal targets. Guanosine monophosphate (GMP) synthase has been identified as an attractive target as it is essential for virulence in the clinically prominent fungal pathogens Aspergillus fumigatus, Candida albicans and Cryptococcus neoformans. However, a lack of structural information on GMP synthase has hindered drug-design efforts. Here, the first structure of a GMP synthase of fungal origin, that from A. fumigatus (at 2.3 Å resolution), is presented. Structural analysis of GMP synthase shows a distinct absence of the D1 dimerization domain that is present in the human homologue. Interestingly, A. fumigatus GMP synthase adopts a dimeric state, as determined by native mass spectrometry and gel-filtration chromatography, in contrast to the monomeric human homologue. Analysis of the substrate-binding pockets of A. fumigatus GMP synthase reveals key differences in the ATP- and XMP-binding sites that can be exploited for species-specific inhibitor drug design. Furthermore, the inhibitory activities of the glutamine analogues acivicin (IC50 = 16.6 ± 2.4 µM) and 6-diazo-5-oxo-L-norleucine (IC50 = 29.6 ± 5.6 µM) against A. fumigatus GMP synthase are demonstrated. Together, these data provide crucial structural information required for specifically targeting A. fumigatus GMP synthase for future antifungal drug-discovery endeavours.
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Hosmer J, Nasreen M, Dhouib R, Essilfie AT, Schirra HJ, Henningham A, Fantino E, Sly P, McEwan AG, Kappler U. Access to highly specialized growth substrates and production of epithelial immunomodulatory metabolites determine survival of Haemophilus influenzae in human airway epithelial cells. PLoS Pathog 2022; 18:e1010209. [PMID: 35085362 PMCID: PMC8794153 DOI: 10.1371/journal.ppat.1010209] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Accepted: 12/14/2021] [Indexed: 11/18/2022] Open
Abstract
Haemophilus influenzae (Hi) infections are associated with recurring acute exacerbations of chronic respiratory diseases in children and adults including otitis media, pneumonia, chronic obstructive pulmonary disease and asthma. Here, we show that persistence and recurrence of Hi infections are closely linked to Hi metabolic properties, where preferred growth substrates are aligned to the metabolome of human airway epithelial surfaces and include lactate, pentoses, and nucleosides, but not glucose that is typically used for studies of Hi growth in vitro. Enzymatic and physiological investigations revealed that utilization of lactate, the preferred Hi carbon source, required the LldD L-lactate dehydrogenase (conservation: 98.8% of strains), but not the two redox-balancing D-lactate dehydrogenases Dld and LdhA. Utilization of preferred substrates was directly linked to Hi infection and persistence. When unable to utilize L-lactate or forced to rely on salvaged guanine, Hi showed reduced extra- and intra-cellular persistence in a murine model of lung infection and in primary normal human nasal epithelia, with up to 3000-fold attenuation observed in competitive infections. In contrast, D-lactate dehydrogenase mutants only showed a very slight reduction compared to the wild-type strain. Interestingly, acetate, the major Hi metabolic end-product, had anti-inflammatory effects on cultured human tissue cells in the presence of live but not heat-killed Hi, suggesting that metabolic endproducts also influence HI-host interactions. Our work provides significant new insights into the critical role of metabolism for Hi persistence in contact with host cells and reveals for the first time the immunomodulatory potential of Hi metabolites.
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Affiliation(s)
- Jennifer Hosmer
- School of Chemistry and Molecular Biosciences, Australian Infectious Diseases Research Centre, The University of Queensland, St. Lucia, Australia
| | - Marufa Nasreen
- School of Chemistry and Molecular Biosciences, Australian Infectious Diseases Research Centre, The University of Queensland, St. Lucia, Australia
| | - Rabeb Dhouib
- School of Chemistry and Molecular Biosciences, Australian Infectious Diseases Research Centre, The University of Queensland, St. Lucia, Australia
| | | | | | - Anna Henningham
- Child Health Research Centre, The University of Queensland, South Brisbane, Australia
| | - Emmanuelle Fantino
- Child Health Research Centre, The University of Queensland, South Brisbane, Australia
| | - Peter Sly
- Child Health Research Centre, The University of Queensland, South Brisbane, Australia
| | - Alastair G. McEwan
- School of Chemistry and Molecular Biosciences, Australian Infectious Diseases Research Centre, The University of Queensland, St. Lucia, Australia
| | - Ulrike Kappler
- School of Chemistry and Molecular Biosciences, Australian Infectious Diseases Research Centre, The University of Queensland, St. Lucia, Australia
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7
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Tan S, Chen Y, Zhou G, Liu J. Transcriptome Analysis of Colletotrichum fructicola Infecting Camellia oleifera Indicates That Two Distinct Geographical Fungi Groups Have Different Destructive Proliferation Capacities Related to Purine Metabolism. PLANTS (BASEL, SWITZERLAND) 2021; 10:plants10122672. [PMID: 34961144 PMCID: PMC8708221 DOI: 10.3390/plants10122672] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 11/19/2021] [Accepted: 11/19/2021] [Indexed: 05/02/2023]
Abstract
Anthracnose, caused by Colletotrichum spp., is a significant disease affecting oil tea (Camellia oleifera Abel.). Extensive molecular studies have demonstrated that Colletotrichum fructicola is the dominant pathogen of oil tea anthracnose in China. This study aims to investigate differences in molecular processes and regulatory genes at a late stage of infection of C. fructicola, to aid in understanding differences in pathogenic mechanisms of C. fructicola of different geographic populations. We compared the pathogenicity of C. fructicola from different populations (Wuzhishan, Hainan province, and Shaoyang, Hunan province) and gene expression of representative strains of the two populations before and after inoculation in oil tea using RNA sequencing. The results revealed that C. fructicola from Wuzhishan has a more vital ability to impact oil tea leaf tissue. Following infection with oil tea leaves, up-regulated genes in the strains from two geographic populations were associated with galactosidase activity, glutamine family amino acid metabolism, arginine, and proline metabolism. Additionally, up-regulated gene lists associated with infection by Wuzhishan strains were significantly enriched in purine metabolism pathways, while Shaoyang strains were not. These results indicate that more transcriptional and translational activity and the greater regulation of the purine metabolism pathway in the C. fructicola of the Wuzhishan strain might contribute to its stronger pathogenicity.
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Affiliation(s)
- Shimeng Tan
- Key Laboratory of National Forestry and Grassland Administration on Control of Artificial Forest Diseases and Pests in South China, Central South University of Forestry and Technology, Changsha 410004, China; (S.T.); (Y.C.); (G.Z.)
- Hunan Provincial Key Laboratory for Control of Forest Diseases and Pests, Central South University of Forestry and Technology, Changsha 410004, China
- Key Laboratory for Non-Wood Forest Cultivation and Conservation of Ministry of Education, Central South University of Forestry and Technology, Changsha 410004, China
- College of Biological Science and Technology, Central South University of Forestry and Technology, Changsha 410004, China
| | - Yanying Chen
- Key Laboratory of National Forestry and Grassland Administration on Control of Artificial Forest Diseases and Pests in South China, Central South University of Forestry and Technology, Changsha 410004, China; (S.T.); (Y.C.); (G.Z.)
- Hunan Provincial Key Laboratory for Control of Forest Diseases and Pests, Central South University of Forestry and Technology, Changsha 410004, China
- Key Laboratory for Non-Wood Forest Cultivation and Conservation of Ministry of Education, Central South University of Forestry and Technology, Changsha 410004, China
- College of Forestry, Central South University of Forestry and Technology, Changsha 410004, China
| | - Guoying Zhou
- Key Laboratory of National Forestry and Grassland Administration on Control of Artificial Forest Diseases and Pests in South China, Central South University of Forestry and Technology, Changsha 410004, China; (S.T.); (Y.C.); (G.Z.)
- Hunan Provincial Key Laboratory for Control of Forest Diseases and Pests, Central South University of Forestry and Technology, Changsha 410004, China
- Key Laboratory for Non-Wood Forest Cultivation and Conservation of Ministry of Education, Central South University of Forestry and Technology, Changsha 410004, China
- College of Biological Science and Technology, Central South University of Forestry and Technology, Changsha 410004, China
| | - Junang Liu
- Key Laboratory of National Forestry and Grassland Administration on Control of Artificial Forest Diseases and Pests in South China, Central South University of Forestry and Technology, Changsha 410004, China; (S.T.); (Y.C.); (G.Z.)
- Hunan Provincial Key Laboratory for Control of Forest Diseases and Pests, Central South University of Forestry and Technology, Changsha 410004, China
- Key Laboratory for Non-Wood Forest Cultivation and Conservation of Ministry of Education, Central South University of Forestry and Technology, Changsha 410004, China
- College of Forestry, Central South University of Forestry and Technology, Changsha 410004, China
- Correspondence:
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8
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Chua SMH, Wizrah MSI, Luo Z, Lim BYJ, Kappler U, Kobe B, Fraser JA. Structural features of Cryptococcus neoformans bifunctional GAR/AIR synthetase may present novel antifungal drug targets. J Biol Chem 2021; 297:101091. [PMID: 34416230 PMCID: PMC8449271 DOI: 10.1016/j.jbc.2021.101091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 08/06/2021] [Accepted: 08/16/2021] [Indexed: 11/18/2022] Open
Abstract
Cryptococcus neoformans is a fungus that causes life-threatening systemic mycoses. During infection of the human host, this pathogen experiences a major change in the availability of purines; the fungus can scavenge the abundant purines in its environmental niche of pigeon excrement, but must employ de novo biosynthesis in the purine-poor human CNS. Eleven sequential enzymatic steps are required to form the first purine base, IMP, an intermediate in the formation of ATP and GTP. Over the course of evolution, several gene fusion events led to the formation of multifunctional purine biosynthetic enzymes in most organisms, particularly the higher eukaryotes. In C. neoformans, phosphoribosyl-glycinamide synthetase (GARs) and phosphoribosyl-aminoimidazole synthetase (AIRs) are fused into a bifunctional enzyme, while the human ortholog is a trifunctional enzyme that also includes GAR transformylase. Here we functionally, biochemically, and structurally characterized C. neoformans GARs and AIRs to identify drug targetable features. GARs/AIRs are essential for de novo purine production and virulence in a murine inhalation infection model. Characterization of GARs enzymatic functional parameters showed that C. neoformans GARs/AIRs have lower affinity for substrates glycine and PRA compared with the trifunctional metazoan enzyme. The crystal structure of C. neoformans GARs revealed differences in the glycine- and ATP-binding sites compared with the Homo sapiens enzyme, while the crystal structure of AIRs shows high structural similarity compared with its H. sapiens ortholog as a monomer but differences as a dimer. The alterations in functional and structural characteristics between fungal and human enzymes could potentially be exploited for antifungal development.
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Affiliation(s)
- Sheena M H Chua
- Australian Infectious Diseases Research Centre, The University of Queensland, St Lucia, Queensland, Australia; School of Chemistry & Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
| | - Maha S I Wizrah
- Australian Infectious Diseases Research Centre, The University of Queensland, St Lucia, Queensland, Australia; School of Chemistry & Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
| | - Zhenyao Luo
- School of Chemistry & Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia; Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, Australia
| | - Bryan Y J Lim
- Australian Infectious Diseases Research Centre, The University of Queensland, St Lucia, Queensland, Australia; School of Chemistry & Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia; Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, Australia
| | - Ulrike Kappler
- Australian Infectious Diseases Research Centre, The University of Queensland, St Lucia, Queensland, Australia; School of Chemistry & Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
| | - Bostjan Kobe
- Australian Infectious Diseases Research Centre, The University of Queensland, St Lucia, Queensland, Australia; School of Chemistry & Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia; Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, Australia
| | - James A Fraser
- Australian Infectious Diseases Research Centre, The University of Queensland, St Lucia, Queensland, Australia; School of Chemistry & Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia.
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9
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Drug repurposing strategies in the development of potential antifungal agents. Appl Microbiol Biotechnol 2021; 105:5259-5279. [PMID: 34151414 PMCID: PMC8214983 DOI: 10.1007/s00253-021-11407-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 06/01/2021] [Accepted: 06/08/2021] [Indexed: 12/15/2022]
Abstract
Abstract The morbidity and mortality caused by invasive fungal infections are increasing across the globe due to developments in transplant surgery, the use of immunosuppressive agents, and the emergence of drug-resistant fungal strains, which has led to a challenge in terms of treatment due to the limitations of three classes of drugs. Hence, it is imperative to establish effective strategies to identify and design new antifungal drugs. Drug repurposing is a potential way of expanding the application of existing drugs. Recently, various existing drugs have been shown to be useful in the prevention and treatment of invasive fungi. In this review, we summarize the currently used antifungal agents. In addition, the most up-to-date information on the effectiveness of existing drugs with antifungal activity is discussed. Moreover, the antifungal mechanisms of existing drugs are highlighted. These data will provide valuable knowledge to stimulate further investigation and clinical application in this field. Key points • Conventional antifungal agents have limitations due to the occurrence of drug-resistant strains. • Non-antifungal drugs act as antifungal agents in various ways toward different targets. • Non-antifungal drugs with antifungal activity are demonstrated as effective antifungal strategies.
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10
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Sun M, Bian Z, Luan Q, Chen Y, Wang W, Dong Y, Chen L, Hao C, Xu JR, Liu H. Stage-specific regulation of purine metabolism during infectious growth and sexual reproduction in Fusarium graminearum. THE NEW PHYTOLOGIST 2021; 230:757-773. [PMID: 33411336 DOI: 10.1111/nph.17170] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 12/23/2020] [Indexed: 06/12/2023]
Abstract
Ascospores generated during sexual reproduction are the primary inoculum for the wheat scab fungus Fusarium graminearum. Purine metabolism is known to play important roles in fungal pathogens but its lifecycle stage-specific regulation is unclear. By characterizing the genes involved in purine de novo and salvage biosynthesis pathways, we showed that de novo syntheses of inosine, adenosine and guanosine monophosphates (IMP, AMP and GMP) are important for vegetative growth, sexual/asexual reproduction, and infectious growth, whereas purine salvage synthesis is dispensable for these stages in F. graminearum. Addition of GMP rescued the defects of the Fgimd1 mutant in vegetative growth and conidiation but not sexual reproduction, whereas addition of AMP rescued all of these defects of the Fgade12 mutant, suggesting that the function of de novo synthesis of GMP rather than AMP is distinct in sexual stages. Moreover, Acd1, an ortholog of AMP deaminase, is dispensable for growth but essential for ascosporogenesis and pathogenesis, suggesting that AMP catabolism has stage-specific functions during sexual reproduction and infectious growth. The expression of almost all the genes involved in de novo purine synthesis is downregulated during sexual reproduction and infectious growth relative to vegetative growth. This study revealed that F. graminearum has stage-specific regulation of purine metabolism during infectious growth and sexual reproduction.
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Affiliation(s)
- Manli Sun
- State Key Laboratory of Crop Stress Biology for Arid Areas, NWAFU-Purdue Joint Research Center, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Zhuyun Bian
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA
| | - Qiaoqiao Luan
- State Key Laboratory of Crop Stress Biology for Arid Areas, NWAFU-Purdue Joint Research Center, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Yitong Chen
- State Key Laboratory of Crop Stress Biology for Arid Areas, NWAFU-Purdue Joint Research Center, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Wei Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, NWAFU-Purdue Joint Research Center, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Yongrong Dong
- State Key Laboratory of Crop Stress Biology for Arid Areas, NWAFU-Purdue Joint Research Center, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Lingfeng Chen
- State Key Laboratory of Crop Stress Biology for Arid Areas, NWAFU-Purdue Joint Research Center, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Chaofeng Hao
- State Key Laboratory of Crop Stress Biology for Arid Areas, NWAFU-Purdue Joint Research Center, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Jin-Rong Xu
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA
| | - Huiquan Liu
- State Key Laboratory of Crop Stress Biology for Arid Areas, NWAFU-Purdue Joint Research Center, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
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11
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Nguyen S, Truong JQ, Bruning JB. Targeting Unconventional Pathways in Pursuit of Novel Antifungals. Front Mol Biosci 2021; 7:621366. [PMID: 33511160 PMCID: PMC7835888 DOI: 10.3389/fmolb.2020.621366] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 12/11/2020] [Indexed: 01/31/2023] Open
Abstract
The impact of invasive fungal infections on human health is a serious, but largely overlooked, public health issue. Commonly affecting the immunocompromised community, fungal infections are predominantly caused by species of Candida, Cryptococcus, and Aspergillus. Treatments are reliant on the aggressive use of pre-existing antifungal drug classes that target the fungal cell wall and membrane. Despite their frequent use, these drugs are subject to unfavorable drug-drug interactions, can cause undesirable side-effects and have compromised efficacy due to the emergence of antifungal resistance. Hence, there is a clear need to develop novel classes of antifungal drugs. A promising approach involves exploiting the metabolic needs of fungi by targeted interruption of essential metabolic pathways. This review highlights potential antifungal targets including enolase, a component of the enolase-plasminogen complex, and enzymes from the mannitol biosynthesis and purine nucleotide biosynthesis pathways. There has been increased interest in the enzymes that comprise these particular pathways and further investigation into their merits as antifungal targets and roles in fungal survival and virulence are warranted. Disruption of these vital processes by targeting unconventional pathways with small molecules or antibodies may serve as a promising approach to discovering novel classes of antifungals.
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Affiliation(s)
- Stephanie Nguyen
- Institute of Photonics and Advanced Sensing (IPAS), School of Biological Sciences, The University of Adelaide, Adelaide, SA, Australia
| | - Jia Q Truong
- School of Biological Sciences, The University of Adelaide, Adelaide, SA, Australia
| | - John B Bruning
- Institute of Photonics and Advanced Sensing (IPAS), School of Biological Sciences, The University of Adelaide, Adelaide, SA, Australia
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12
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Nguyen S, Jovcevski B, Pukala TL, Bruning JB. Nucleoside selectivity of Aspergillus fumigatus nucleoside-diphosphate kinase. FEBS J 2020; 288:2398-2417. [PMID: 33089641 DOI: 10.1111/febs.15607] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 10/06/2020] [Accepted: 10/19/2020] [Indexed: 11/29/2022]
Abstract
Aspergillus fumigatus infections are rising at a disconcerting rate in tandem with antifungal resistance rates. Efforts to develop novel antifungals have been hindered by the limited knowledge of fundamental biological and structural mechanisms of A. fumigatus propagation. Biosynthesis of NTPs, the building blocks of DNA and RNA, is catalysed by NDK. An essential enzyme in A. fumigatus, NDK poses as an attractive target for novel antifungals. NDK exhibits broad substrate specificity across species, using both purines and pyrimidines, but the selectivity of such nucleosides in A. fumigatus NDK is unknown, impeding structure-guided inhibitor design. Structures of NDK in unbound- and NDP-bound states were solved, and NDK activity was assessed in the presence of various NTP substrates. We present the first instance of a unique substrate binding mode adopted by CDP and TDP specific to A. fumigatus NDK that illuminates the structural determinants of selectivity. Analysis of the oligomeric state reveals that A. fumigatus NDK adopts a hexameric assembly in both unbound- and NDP-bound states, contrary to previous reports suggesting it is tetrameric. Kinetic analysis revealed that ATP exhibited the greatest turnover rate (321 ± 33.0 s-1 ), specificity constant (626 ± 110.0 mm-1 ·s-1 ) and binding free energy change (-37.0 ± 3.5 kcal·mol-1 ). Comparatively, cytidine nucleosides displayed the slowest turnover rate (53.1 ± 3.7 s-1 ) and lowest specificity constant (40.2 ± 4.4 mm-1 ·s-1 ). We conclude that NDK exhibits nucleoside selectivity whereby adenine nucleosides are used preferentially compared to cytidine nucleosides, and these insights can be exploited to guide drug design. ENZYMES: Nucleoside-diphosphate kinase (EC 2.7.4.6). DATABASE: Structural data are available in the PDB database under the accession numbers: Unbound-NDK (6XP4), ADP-NDK (6XP7), GDP-NDK (6XPS), IDP-NDK (6XPU), UDP-NDK (6XPT), CDP-NDK (6XPW), TDP-NDK (6XPV).
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Affiliation(s)
- Stephanie Nguyen
- Institute of Photonics and Advanced Sensing (IPAS), School of Biological Sciences, The University of Adelaide, Australia
| | - Blagojce Jovcevski
- Adelaide Proteomics Centre, School of Physical Sciences, The University of Adelaide, Australia.,School of Agriculture, Food and Wine, The University of Adelaide, Australia
| | - Tara L Pukala
- Adelaide Proteomics Centre, School of Physical Sciences, The University of Adelaide, Australia
| | - John B Bruning
- Institute of Photonics and Advanced Sensing (IPAS), School of Biological Sciences, The University of Adelaide, Australia
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13
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Chua SM, Fraser JA. Surveying purine biosynthesis across the domains of life unveils promising drug targets in pathogens. Immunol Cell Biol 2020; 98:819-831. [PMID: 32748425 DOI: 10.1111/imcb.12389] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 07/30/2020] [Accepted: 07/30/2020] [Indexed: 12/11/2022]
Abstract
Purines play an integral role in cellular processes such as energy metabolism, cell signaling and encoding the genetic makeup of all living organisms-ensuring that the purine metabolic pathway is maintained across all domains of life. To gain a deeper understanding of purine biosynthesis via the de novo biosynthetic pathway, the genes encoding purine metabolic enzymes from 35 archaean, 69 bacterial and 99 eukaryotic species were investigated. While the classic elements of the canonical purine metabolic pathway were utilized in all domains, a subset of familiar biochemical roles was found to be performed by unrelated proteins in some members of the Archaea and Bacteria. In the Bacteria, a major differentiating feature of de novo purine biosynthesis is the increasing prevalence of gene fusions, where two or more purine biosynthesis enzymes that perform consecutive biochemical functions in the pathway are encoded by a single gene. All species in the Eukaryota exhibited the most common fusions seen in the Bacteria, in addition to new gene fusions to potentially increase metabolic flux. This complexity is taken further in humans, where a reversible biomolecular assembly of enzymes known as the purinosome has been identified, allowing short-term regulation in response to metabolic cues while expanding on the benefits that can come from gene fusion. By surveying purine metabolism across all domains of life, we have identified important features of the purine biosynthetic pathway that can potentially be exploited as prospective drug targets.
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Affiliation(s)
- Sheena Mh Chua
- Australian Infectious Diseases Research Centre, School of Chemistry & Molecular Biosciences, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - James A Fraser
- Australian Infectious Diseases Research Centre, School of Chemistry & Molecular Biosciences, The University of Queensland, Brisbane, QLD, 4072, Australia
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14
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Nass K, Redecke L, Perbandt M, Yefanov O, Klinge M, Koopmann R, Stellato F, Gabdulkhakov A, Schönherr R, Rehders D, Lahey-Rudolph JM, Aquila A, Barty A, Basu S, Doak RB, Duden R, Frank M, Fromme R, Kassemeyer S, Katona G, Kirian R, Liu H, Majoul I, Martin-Garcia JM, Messerschmidt M, Shoeman RL, Weierstall U, Westenhoff S, White TA, Williams GJ, Yoon CH, Zatsepin N, Fromme P, Duszenko M, Chapman HN, Betzel C. In cellulo crystallization of Trypanosoma brucei IMP dehydrogenase enables the identification of genuine co-factors. Nat Commun 2020; 11:620. [PMID: 32001697 PMCID: PMC6992785 DOI: 10.1038/s41467-020-14484-w] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 01/06/2020] [Indexed: 02/07/2023] Open
Abstract
Sleeping sickness is a fatal disease caused by the protozoan parasite Trypanosoma brucei (Tb). Inosine-5’-monophosphate dehydrogenase (IMPDH) has been proposed as a potential drug target, since it maintains the balance between guanylate deoxynucleotide and ribonucleotide levels that is pivotal for the parasite. Here we report the structure of TbIMPDH at room temperature utilizing free-electron laser radiation on crystals grown in living insect cells. The 2.80 Å resolution structure reveals the presence of ATP and GMP at the canonical sites of the Bateman domains, the latter in a so far unknown coordination mode. Consistent with previously reported IMPDH complexes harboring guanosine nucleotides at the second canonical site, TbIMPDH forms a compact oligomer structure, supporting a nucleotide-controlled conformational switch that allosterically modulates the catalytic activity. The oligomeric TbIMPDH structure we present here reveals the potential of in cellulo crystallization to identify genuine allosteric co-factors from a natural reservoir of specific compounds. Trypanosoma brucei inosine-5′-monophosphate dehydrogenase (IMPDH) is an enzyme in the guanine nucleotide biosynthesis pathway and of interest as a drug target. Here the authors present the 2.8 Å room temperature structure of TbIMPDH determined by utilizing X-ray free-electron laser radiation and crystals that were grown in insect cells and find that ATP and GMP are bound at the canonical sites of the Bateman domains.
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Affiliation(s)
- Karol Nass
- Center for Free-Electron Laser Science (CFEL), Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607, Hamburg, Germany.,Paul Scherrer Institute (PSI), Forschungstrasse 111, 5232, Villigen, PSI, Switzerland
| | - Lars Redecke
- Joint Laboratory for Structural Biology of Infection and Inflammation, Institute of Biochemistry and Molecular Biology, University of Hamburg, and Institute of Biochemistry, University of Lübeck, at Deutsches Elektronen-Synchrotron (DESY), Notkestr. 85, 22607, Hamburg, Germany.,German Centre for Infection Research, University of Lübeck, 23562, Lübeck, Germany.,Institute of Biochemistry, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany.,Deutsches Elektronen Synchrotron (DESY), Photon Science, Notkestr. 85, 22607, Hamburg, Germany
| | - M Perbandt
- Institute of Biochemistry and Molecular Biology, University of Hamburg, at Deutsches Elektronen-Synchrotron (DESY), Notkestr. 85, 22607, Hamburg, Germany.,The Hamburg Centre for Ultrafast Imaging (CUI), Luruper Chaussee 149, 22761, Hamburg, Germany
| | - O Yefanov
- Center for Free-Electron Laser Science (CFEL), Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607, Hamburg, Germany
| | - M Klinge
- Joint Laboratory for Structural Biology of Infection and Inflammation, Institute of Biochemistry and Molecular Biology, University of Hamburg, and Institute of Biochemistry, University of Lübeck, at Deutsches Elektronen-Synchrotron (DESY), Notkestr. 85, 22607, Hamburg, Germany.,BioAgilytix Europe GmbH, Lademannbogen 10, 22339, Hamburg, Germany
| | - R Koopmann
- Interfaculty Institute of Biochemistry, University of Tübingen, Hoppe-Seyler-Str.4, 72076, Tübingen, Germany
| | - F Stellato
- Center for Free-Electron Laser Science (CFEL), Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607, Hamburg, Germany.,Dipartimento di Fisica, Università di Roma Tor Vergata and INFN, Via della Ricerca Scientifica 1, 00133, Rome, Italy
| | - A Gabdulkhakov
- Institute of Protein Research, Russian Academy of Sciences, 4 Institutskaya Str., Pushchino, Moscow Region, Russia, 142290
| | - R Schönherr
- Institute of Biochemistry, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany.,Deutsches Elektronen Synchrotron (DESY), Photon Science, Notkestr. 85, 22607, Hamburg, Germany
| | - D Rehders
- Joint Laboratory for Structural Biology of Infection and Inflammation, Institute of Biochemistry and Molecular Biology, University of Hamburg, and Institute of Biochemistry, University of Lübeck, at Deutsches Elektronen-Synchrotron (DESY), Notkestr. 85, 22607, Hamburg, Germany.,BODE Chemie GmbH, Melanchthonstraße 27, 22525, Hamburg, Germany
| | - J M Lahey-Rudolph
- Center for Free-Electron Laser Science (CFEL), Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607, Hamburg, Germany.,Institute of Biochemistry, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany
| | - A Aquila
- Center for Free-Electron Laser Science (CFEL), Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607, Hamburg, Germany.,LCLS, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - A Barty
- Center for Free-Electron Laser Science (CFEL), Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607, Hamburg, Germany
| | - S Basu
- Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ, 85287-160, USA.,European Molecular Biology Laboratory (EMBL), Grenoble Outstation, 71 Avenue des Martyrs, CS 90181, 38042 Grenoble Cedex 9, Grenoble, France
| | - R B Doak
- Department of Physics, Arizona State University, Tempe, AZ, 85411, USA.,Max Planck Institute for Medical Research, Jahnstr. 29, 69120, Heidelberg, Germany
| | - R Duden
- Institute of Biology, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany
| | - M Frank
- Biology and Biotechnology Division, Physical & Life Sciences Directorate, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA, 94550, USA
| | - R Fromme
- Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ, 85287-160, USA
| | - S Kassemeyer
- Max-Planck-Institute for Medical Research, Jahnstr. 29, 69120, Heidelberg, Germany
| | - G Katona
- Department of Chemistry and Molecular Biology, University of Gothenburg, 40530, Gothenburg, Sweden
| | - R Kirian
- Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ, 85287-160, USA
| | - H Liu
- Department of Physics, Arizona State University, Tempe, AZ, 85411, USA.,Complex Systems Division, Beijing Computational Science Research Center, 100193, Beijing, China
| | - I Majoul
- Institute of Biology, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany
| | - J M Martin-Garcia
- Center for Applied Structural Discovery (CASD), Biodesign Institute, Arizona State University, 727 East Tyler Street, Tempe, AZ, 85287, USA
| | - M Messerschmidt
- LCLS, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA.,Center for Applied Structural Discovery (CASD), Biodesign Institute, Arizona State University, 727 East Tyler Street, Tempe, AZ, 85287, USA
| | - R L Shoeman
- Max-Planck-Institute for Medical Research, Jahnstr. 29, 69120, Heidelberg, Germany
| | - U Weierstall
- Department of Physics, Arizona State University, Tempe, AZ, 85411, USA
| | - S Westenhoff
- Department of Chemistry and Molecular Biology, University of Gothenburg, 40530, Gothenburg, Sweden
| | - T A White
- Center for Free-Electron Laser Science (CFEL), Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607, Hamburg, Germany
| | - G J Williams
- LCLS, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA.,Brookhaven National Laboratory (BNL), PO Box 5000, Upton, NY, 11973-5000, USA
| | - C H Yoon
- Center for Free-Electron Laser Science (CFEL), Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607, Hamburg, Germany.,LCLS, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - N Zatsepin
- Department of Physics, Arizona State University, Tempe, AZ, 85411, USA.,ARC Centre of Excellence in Advanced Molecular Imaging, Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Victoria, 3086, Australia
| | - P Fromme
- Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ, 85287-160, USA
| | - M Duszenko
- Institute of Neurophysiology, University of Tübingen, Keplerstr. 15, 72074, Tübingen, Germany
| | - H N Chapman
- Center for Free-Electron Laser Science (CFEL), Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607, Hamburg, Germany.,The Hamburg Centre for Ultrafast Imaging (CUI), Luruper Chaussee 149, 22761, Hamburg, Germany.,Department of Physics, University of Hamburg, Luruper Chaussee 149, 22761, Hamburg, Germany
| | - C Betzel
- Institute of Biochemistry and Molecular Biology, University of Hamburg, at Deutsches Elektronen-Synchrotron (DESY), Notkestr. 85, 22607, Hamburg, Germany. .,The Hamburg Centre for Ultrafast Imaging (CUI), Luruper Chaussee 149, 22761, Hamburg, Germany.
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15
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Zhang M, Yan H, Lu M, Wang D, Sun S. Antifungal activity of ribavirin used alone or in combination with fluconazole against Candida albicans is mediated by reduced virulence. Int J Antimicrob Agents 2019; 55:105804. [PMID: 31605727 DOI: 10.1016/j.ijantimicag.2019.09.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 09/07/2019] [Accepted: 09/11/2019] [Indexed: 01/01/2023]
Abstract
The incidence of fungal infections has increased continuously in recent years, and drug resistance, especially resistance to fluconazole (FLC), has emerged. To overcome this challenge, research on the antifungal activities of non-antifungal agents has gained more attention. In this study, we determined the anti-Candida activity of ribavirin (RBV), an antiviral drug commonly used in the clinic, and found that RBV displayed potent antifungal activity when used alone or in combination with FLC in vitro and in vivo. In vitro, the MIC80 values of RBV were 2-4 µg/mL for FLC-susceptible Candida albicans and 8 µg/mL for FLC-resistant C. albicans. When RBV at a dose of 1 µg/mL was combined with FLC, significant synergistic effects were exhibited against FLC-resistant C. albicans, and the MICs of FLC decreased from >512 µg/mL to 0.25-1 µg/mL. Synergism was also exhibited against C. albicans biofilms. In vivo, RBV plus FLC significantly improved the survival of infected Galleria mellonella larvae compared with the FLC-treated group over a 4-day period and attenuated the damage of FLC-resistant C. albicans to G. mellonella larvae tissue. Furthermore, mechanistic studies indicated that the antifungal effects of RBV used alone or in combination with FLC might be associated with inhibition of biofilm formation, reduced extracellular phospholipase activity and inhibition of hyphal growth, but is not related to promotion of FLC uptake and inhibition of FLC efflux. These results provide a promising direction for overcoming drug resistance and for expanding the clinical application of existing drugs.
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Affiliation(s)
- Min Zhang
- School of Pharmaceutical Sciences, Shandong First Medical University, Tai'an, Shandong Province, China; Department of Pharmacy, Tai'an Municipal Hospital, Tai'an, Shandong Province, China
| | - Haiying Yan
- Department of Pharmacy, Shandong Provincial Qianfoshan Hospital, the First Hospital Affiliated with Shandong First Medical University, Jinan, Shandong Province, China
| | - Mengjiao Lu
- Department of Pharmacy, Tianjin Baodi Hospital, Baodi Clinical College of Tianjin Medical University, Tianjin, China
| | - Decai Wang
- School of Pharmaceutical Sciences, Shandong First Medical University, Tai'an, Shandong Province, China
| | - Shujuan Sun
- Department of Pharmacy, Shandong Provincial Qianfoshan Hospital, the First Hospital Affiliated with Shandong First Medical University, Jinan, Shandong Province, China.
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16
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O'Neill EC, Schorn M, Larson CB, Millán-Aguiñaga N. Targeted antibiotic discovery through biosynthesis-associated resistance determinants: target directed genome mining. Crit Rev Microbiol 2019; 45:255-277. [PMID: 30985219 DOI: 10.1080/1040841x.2019.1590307] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Intense competition between microbes in the environment has directed the evolution of antibiotic production in bacteria. Humans have harnessed these natural molecules for medicinal purposes, magnifying them from environmental concentrations to industrial scale. This increased exposure to antibiotics has amplified antibiotic resistance across bacteria, spurring a global antimicrobial crisis and a search for antibiotics with new modes of action. Genetic insights into these antibiotic-producing microbes reveal that they have evolved several resistance strategies to avoid self-toxicity, including product modification, substrate transport and binding, and target duplication or modification. Of these mechanisms, target duplication or modification will be highlighted in this review, as it uniquely links an antibiotic to its mode of action. We will further discuss and propose a strategy to mine microbial genomes for these genes and their associated biosynthetic gene clusters to discover novel antibiotics using target directed genome mining.
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Affiliation(s)
- Ellis C O'Neill
- a Department of Plant Sciences, University of Oxford , Oxford , Oxfordshire , UK
| | - Michelle Schorn
- b Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California , San Diego , CA , USA
| | - Charles B Larson
- b Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California , San Diego , CA , USA
| | - Natalie Millán-Aguiñaga
- c Universidad Autónoma de Baja California, Facultad de Ciencias Marinas , Ensenada , Baja California , México
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17
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Yang L, Ru Y, Cai X, Yin Z, Liu X, Xiao Y, Zhang H, Zheng X, Wang P, Zhang Z. MoImd4 mediates crosstalk between MoPdeH-cAMP signalling and purine metabolism to govern growth and pathogenicity in Magnaporthe oryzae. MOLECULAR PLANT PATHOLOGY 2019; 20:500-518. [PMID: 30426699 PMCID: PMC6422694 DOI: 10.1111/mpp.12770] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The high-affinity cyclic adenosine monophosphate (cAMP) phosphodiesterase MoPdeH is important not only for cAMP signalling and pathogenicity, but also for cell wall integrity (CWI) maintenance in the rice blast fungus Magnaporthe oryzae. To explore the underlying mechanism, we identified MoImd4 as an inosine-5'-monophosphate dehydrogenase (IMPDH) homologue that interacts with MoPdeH. Targeted deletion of MoIMD4 resulted in reduced de novo purine biosynthesis and growth, as well as attenuated pathogenicity, which were suppressed by exogenous xanthosine monophosphate (XMP). Treatment with mycophenolic acid (MPA), which specifically inhibits MoImd4 activity, resulted in reduced growth and virulence attenuation. Intriguingly, further analysis showed that MoImd4 promotes the phosphodiesterase activity of MoPdeH, thereby decreasing intracellular cAMP levels, and MoPdeH also promotes the IMPDH activity of MoImd4. Our studies revealed the presence of a novel crosstalk between cAMP regulation and purine biosynthesis in M. oryzae, and indicated that such a link is also important in the pathogenesis of M. oryzae.
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Affiliation(s)
- Lina Yang
- Department of Plant Pathology, College of Plant ProtectionNanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of EducationNanjing210095China
| | - Yanyan Ru
- Department of Plant Pathology, College of Plant ProtectionNanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of EducationNanjing210095China
| | - Xingjia Cai
- Department of Plant Pathology, College of Plant ProtectionNanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of EducationNanjing210095China
| | - Ziyi Yin
- Department of Plant Pathology, College of Plant ProtectionNanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of EducationNanjing210095China
| | - Xinyu Liu
- Department of Plant Pathology, College of Plant ProtectionNanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of EducationNanjing210095China
| | - Yuhan Xiao
- Department of Plant Pathology, College of Plant ProtectionNanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of EducationNanjing210095China
| | - Haifeng Zhang
- Department of Plant Pathology, College of Plant ProtectionNanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of EducationNanjing210095China
| | - Xiaobo Zheng
- Department of Plant Pathology, College of Plant ProtectionNanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of EducationNanjing210095China
| | - Ping Wang
- Departments of Pediatrics, and Microbiology, Immunology, and ParasitologyLouisiana State University Health Sciences CenterNew OrleansLA70112USA
| | - Zhengguang Zhang
- Department of Plant Pathology, College of Plant ProtectionNanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of EducationNanjing210095China
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18
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Quantitation of Purines from Pigeon Guano and Implications for Cryptococcus neoformans Survival During Infection. Mycopathologia 2019; 184:273-281. [PMID: 30707338 DOI: 10.1007/s11046-018-0315-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 12/22/2018] [Indexed: 10/27/2022]
Abstract
The fertilizing properties of bird manure, or guano, have played an important role in plant cultivation for thousands of years. Research into its chemical composition by Unger in 1846 identified a novel compound, now known as guanine, a purine base that is essential for DNA and RNA biosynthesis and cell signalling. Nitrogen-rich guano can also harbour human pathogens, one significant example being the fungal pathogen Cryptococcus neoformans. Historically associated with pigeon droppings, C. neoformans is able to infect immunocompromised individuals with the aid of a number of adaptive virulence traits. To gain insight into this niche, a quantitative analysis of pigeon guano was performed by LC/MS to determine the concentrations of purines present. Guanine was found in abundance, in particular, in aged guano samples that contained 156-296 μg/g [w/w] compared to 75 μg/g in fresh guano. Adenine concentrations were more consistent between fresh and aged samples, 13 μg/g compared to 10-15 μg/g, respectively. C. neoformans strains that lack key enzymes of the de novo purine synthesis pathway and are guanine or adenine auxotrophs displayed differences in their ability to exploit this substrate: growth of a guanine auxotrophic mutant (gua1Δ) was partially restored on 30% pigeon guano media, but an adenine auxotrophic mutant (ade13Δ) was unable to grow. We conclude that while purine salvage is likely a useful resource-saving mechanism, alone it is not sufficient to fully provide the purines required by wild-type C. neoformans growing in its guano niche.
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19
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Zhang M, Yang X, Wang D, Yu C, Sun S. Antifungal activity of immunosuppressants used alone or in combination with fluconazole. J Appl Microbiol 2018; 126:1304-1317. [PMID: 30307675 DOI: 10.1111/jam.14126] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 09/07/2018] [Accepted: 09/29/2018] [Indexed: 01/26/2023]
Abstract
Fungal infections remain a challenge to clinicians due to the limited available antifungals. With the increasing use of antifungals in clinical practice, drug resistance has been emerging continuously, especially to fluconazole (FLC). Thus, a search for new antifungals and approaches to overcome antifungal resistance is needed. However, the development of new antifungals is usually costly and time consuming; discovering the antifungal activity of non-antifungal agents is one way to address these problems. Interestingly, some researchers have demonstrated that several classes of immunosuppressants (calcineurin inhibitors, glucocorticoids, etc) also displayed potent antifungal activity when used alone or in combination with antifungals, especially with FLC. Some of them could increase FLC's susceptibility against resistant Candida albicans significantly reversing fungal resistance to FLC. This article reviews the antifungal activities of immunosuppressants used alone or in combination with antifungals and their potential antifungal mechanisms that have been discovered so far. Although immunosuppressive agents have been identified as risk factors for fungal infection, we believe these findings are very important for overcoming drug resistance and developing new antifungals.
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Affiliation(s)
- M Zhang
- School of Pharmaceutical Sciences, Taishan Medical University, Taian, Shandong Province, China
| | - X Yang
- Department of Pharmacy, Qianfoshan Hospital Affiliated to Shandong University, Jinan, Shandong Province, China
| | - D Wang
- School of Pharmaceutical Sciences, Taishan Medical University, Taian, Shandong Province, China
| | - C Yu
- Department of Pharmacy, Qianfoshan Hospital Affiliated to Shandong University, Jinan, Shandong Province, China
| | - S Sun
- Department of Pharmacy, Qianfoshan Hospital Affiliated to Shandong University, Jinan, Shandong Province, China
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20
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Kummari LK, Butler MS, Furlong E, Blundell R, Nouwens A, Silva AB, Kappler U, Fraser JA, Kobe B, Cooper MA, Robertson AAB. Antifungal benzo[b]thiophene 1,1-dioxide IMPDH inhibitors exhibit pan-assay interference (PAINS) profiles. Bioorg Med Chem 2018; 26:5408-5419. [PMID: 30322754 DOI: 10.1016/j.bmc.2018.09.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 08/21/2018] [Accepted: 09/03/2018] [Indexed: 12/14/2022]
Abstract
Fungi cause serious life-threatening infections in immunocompromised individuals and current treatments are now complicated by toxicity issues and the emergence of drug resistant strains. Consequently, there is a need for development of new antifungal drugs. Inosine monophosphate dehydrogenase (IMPDH), a key component of the de novo purine biosynthetic pathway, is essential for growth and virulence of fungi and is a potential drug target. In this study, a high-throughput screen of 114,000 drug-like compounds against Cryptococcus neoformans IMPDH was performed. We identified three 3-((5-substituted)-1,3,4-oxadiazol-2-yl)thio benzo[b]thiophene 1,1-dioxides that inhibited Cryptococcus IMPDH and also possessed whole cell antifungal activity. Analogs were synthesized to explore the SAR of these hits. Modification of the fifth substituent on the 1,3,4-oxadiazole ring yielded compounds with nanomolar in vitro activity, but with associated cytotoxicity. In contrast, two analogs generated by substituting the 1,3,4-oxadiazole ring with imidazole and 1,2,4-triazole gave reduced IMPDH inhibition in vitro, but were not cytotoxic. During enzyme kinetic studies in the presence of DTT, nucleophilic attack of a free thiol occurred with the benzo[b]thiophene 1,1-dioxide. Two representative compounds with substitution at the 5 position of the 1,3,4-oxadiazole ring, showed mixed inhibition in the absence of DTT. Incubation of these compounds with Cryptococcus IMPDH followed by mass spectrometry analysis showed non-specific and covalent binding with IMPDH at multiple cysteine residues. These results support recent reports that the benzo[b]thiophene 1,1-dioxides moiety as PAINS (pan-assay interference compounds) contributor.
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Affiliation(s)
- Lalith K Kummari
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia; Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia; Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Mark S Butler
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Emily Furlong
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Ross Blundell
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Amanda Nouwens
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Alberto B Silva
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia; AC Immune SA, EPFL Innovation Park, CH-1015 Lausanne, Switzerland
| | - Ulrike Kappler
- Centre for Metals in Biology, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - James A Fraser
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Bostjan Kobe
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia; Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Matthew A Cooper
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Avril A B Robertson
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia; Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia.
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21
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Zhou N, Bottagisi S, Katz M, Schacherer J, Friedrich A, Gojkovic Z, Swamy KBS, Knecht W, Compagno C, Piškur J. Yeast-bacteria competition induced new metabolic traits through large-scale genomic rearrangements in Lachancea kluyveri. FEMS Yeast Res 2018; 17:4064365. [PMID: 28910985 DOI: 10.1093/femsyr/fox060] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 08/03/2017] [Indexed: 12/28/2022] Open
Abstract
Large-scale chromosomal rearrangements are an important source of evolutionary novelty that may have reshaped the genomes of existing yeast species. They dramatically alter genome organization and gene expression fueling a phenotypic leap in response to environmental constraints. Although the emergence of such signatures of genetic diversity is thought to be associated with human exploitation of yeasts, less is known about the driving forces operating in natural habitats. Here we hypothesize that an ecological battlefield characteristic of every autumn when fruits ripen accounts for the genomic innovations in natural populations. We described a long-term cross-kingdom competition experiment between Lachancea kluyveri and five species of bacteria. Now, we report how we further subjected the same yeast to a sixth species of bacteria, Pseudomonas fluorescens, resulting in the appearance of a fixed and stably inherited large-scale genomic rearrangement in two out of three parallel evolution lines. The 'extra-banded' karyotype, characterized by a higher fitness and an elevated fermentative capacity, conferred the emergence of new metabolic traits in most carbon sources and osmolytes. We tracked down the event to a duplication and translocation event involving a 261-kb segment. Such an experimental setup described here is an attractive method for developing industrial strains without genetic engineering strategies.
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Affiliation(s)
- Nerve Zhou
- Department of Biology, Lund University, Sölvegatan 35, 22362 Lund, Sweden.,Department of Biological Sciences and Biotechnology, Botswana International University of Science and Technology, P Bag 16, 00267 Palapye, Botswana
| | - Samuele Bottagisi
- Department of Biology, Lund University, Sölvegatan 35, 22362 Lund, Sweden.,Department of Biology and Biotechnology, University of Pavia, 27100 Pavia, Italy
| | - Michael Katz
- Carlsberg Laboratories, Gamle Carlsberg Vej 10, 1799 Copenhagen V, Denmark
| | - Joseph Schacherer
- Department of Genetics, Genomics and Microbiology, University of Strasbourg, CNRS UMR7156, 67083 Strasbourg, France
| | - Anne Friedrich
- Department of Genetics, Genomics and Microbiology, University of Strasbourg, CNRS UMR7156, 67083 Strasbourg, France
| | - Zoran Gojkovic
- Carlsberg Laboratories, Gamle Carlsberg Vej 10, 1799 Copenhagen V, Denmark
| | - Krishna B S Swamy
- Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Wolfgang Knecht
- Department of Biology, Lund University, Sölvegatan 35, 22362 Lund, Sweden.,Lund Protein Production Platform, Lund University, Sölvegatan 35, 22362 Lund, Sweden
| | - Concetta Compagno
- Department of Food, Environmental and Nutritional Sciences, University of Milan, Via Giovanni Celoria 2, 20133 Milan, Italy
| | - Jure Piškur
- Department of Biology, Lund University, Sölvegatan 35, 22362 Lund, Sweden
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22
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Matsumoto Y, Ishii M, Shimizu K, Kawamoto S, Sekimizu K. [A Silkworm Infection Model to Evaluate Antifungal Drugs for Cryptococcosis]. Med Mycol J 2018; 58:E131-E137. [PMID: 29187715 DOI: 10.3314/mmj.17.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The development of effective drugs against fungal diseases involves performing infection experiments in animals to evaluate candidate therapeutic compounds. Cryptococcus neoformans is a pathogenic fungus that causes deep mycosis, resulting in respiratory illness and meningitis. Here we describe a silkworm system established to evaluate the safety and efficacy of therapeutic drugs against infection by Cryptococcus neoformans and the advantages of this system over other animal models. The silkworm assay system has two major advantages: 1) silkworms are less expensive to rear and their use is less problematic than that of mammals in terms of animal welfare, and 2) in vivo screenings for identifying candidate drugs can be easily performed using a large number of silkworms. The pharmacokinetics of compounds are consistent between silkworms and mammals. Moreover, the ED50 values of antibiotics are concordant between mammalian and silkworm infection models. Furthermore, the body size of silkworms makes them easy to handle in experimental procedures compared with other invertebrate infectious experimental systems, and accurate amounts of pathogens and chemicals can be injected fairly easily. These advantages of silkworms as a host animal make them useful for screening candidate drugs for cryptococcosis.
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Affiliation(s)
| | - Masaki Ishii
- Teikyo University Institute of Medical Mycology.,Genome Pharmaceuticals Institute Co. Ltd
| | - Kiminori Shimizu
- Department of Biological Science and Technology, Tokyo University of Science
| | | | - Kazuhisa Sekimizu
- Teikyo University Institute of Medical Mycology.,Genome Pharmaceuticals Institute Co. Ltd
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23
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Transcriptome-wide survey of gene expression changes and alternative splicing in Trichophyton rubrum in response to undecanoic acid. Sci Rep 2018; 8:2520. [PMID: 29410524 PMCID: PMC5802734 DOI: 10.1038/s41598-018-20738-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 01/18/2018] [Indexed: 12/29/2022] Open
Abstract
While fatty acids are known to be toxic to dermatophytes, key physiological aspects of the Trichophyton rubrum response to undecanoic acid (UDA), a medium chain saturated fatty acid (C11:0), are not well understood. Thus, we analysed RNA-seq data from T. rubrum exposed to sub-lethal doses of UDA for 3 and 12 h. Three putative pathways were primarily involved in UDA detoxification: lipid metabolism and cellular membrane composition, oxidative stress, and pathogenesis. Biochemical assays showed cell membrane impairment, reductions in ergosterol content, and an increase in keratinolytic activity following UDA exposure. Moreover, we assessed differential exon usage and intron retention following UDA exposure. A key enzyme supplying guanine nucleotides to cells, inosine monophosphate dehydrogenase (IMPDH), showed high levels of intron 2 retention. Additionally, phosphoglucomutase (PGM), which is involved in the glycogen synthesis and degradation as well as cell wall biosynthesis, exhibited a significant difference in exon 4 usage following UDA exposure. Owing to the roles of these enzymes in fungal cells, both have emerged as promising antifungal targets. We showed that intron 2 retention in impdh and exon 4 skipping in pgm might be related to an adaptive strategy to combat fatty acid toxicity. Thus, the general effect of UDA fungal toxicity involves changes to fungal metabolism and mechanisms for regulating pre-mRNA processing events.
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24
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Peng Y, Zhang H, Xu M, Tan MW. A Tet-Off gene expression system for validation of antifungal drug targets in a murine invasive pulmonary aspergillosis model. Sci Rep 2018; 8:443. [PMID: 29323188 PMCID: PMC5765126 DOI: 10.1038/s41598-017-18868-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 12/18/2017] [Indexed: 12/20/2022] Open
Abstract
Aspergillus fumigatus is one of the major causes of invasive pulmonary aspergillosis in immunocompromised patients. Novel antifungal therapy is in urgent need due to emerging resistance and adverse toxicity of current antifungal drugs. Gene products that are essential for Aspergillus viability during infection are attractive drug targets. To characterize these genes in vivo we developed a Tet-Off gene expression system in A. fumigatus, whereby the administration of doxycycline resulted in down regulation of the gene whose expression is under the control of the Tet-Off promoter. We tested the system on two potential drug targets, inosine 5′-monophosphate dehydrogenase (IMPDH) and L-ornithine N5-oxygenase (sidA) in a murine invasive pulmonary aspergillosis model. We show that depletion of IMPDH attenuated but did not completely abolish virulence in vivo whereas turning off the expression of sidA, which is required for iron acquisition, resulted in avirulence. We also investigated whether sidA expression could be controlled in a time-dependent manner in mice. Our results demonstrated that timing of doxycycline administration dramatically affects survival rate, suggesting that this genetic system can be used for testing whether an antifungal drug target is critical for fungal growth post-infection.
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Affiliation(s)
- Yutian Peng
- Infectious Diseases Department, Genentech Inc., South San Francisco, California, 94080, USA.
| | - Hua Zhang
- Translational Immunology Department, Genentech Inc., South San Francisco, California, 94080, USA
| | - Min Xu
- Translational Immunology Department, Genentech Inc., South San Francisco, California, 94080, USA
| | - Man-Wah Tan
- Infectious Diseases Department, Genentech Inc., South San Francisco, California, 94080, USA.
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25
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Liu N, Tu J, Dong G, Wang Y, Sheng C. Emerging New Targets for the Treatment of Resistant Fungal Infections. J Med Chem 2018; 61:5484-5511. [DOI: 10.1021/acs.jmedchem.7b01413] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Na Liu
- School of Pharmacy, Second Military Medical University, 325 Guohe Road, Shanghai 200433, People’s Republic of China
| | - Jie Tu
- School of Pharmacy, Second Military Medical University, 325 Guohe Road, Shanghai 200433, People’s Republic of China
| | - Guoqiang Dong
- School of Pharmacy, Second Military Medical University, 325 Guohe Road, Shanghai 200433, People’s Republic of China
| | - Yan Wang
- School of Pharmacy, Second Military Medical University, 325 Guohe Road, Shanghai 200433, People’s Republic of China
| | - Chunquan Sheng
- School of Pharmacy, Second Military Medical University, 325 Guohe Road, Shanghai 200433, People’s Republic of China
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26
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Cai X, Zhang X, Li X, Liu M, Liu X, Wang X, Zhang H, Zheng X, Zhang Z. The Atypical Guanylate Kinase MoGuk2 Plays Important Roles in Asexual/Sexual Development, Conidial Septation, and Pathogenicity in the Rice Blast Fungus. Front Microbiol 2017; 8:2467. [PMID: 29321770 PMCID: PMC5732230 DOI: 10.3389/fmicb.2017.02467] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 11/28/2017] [Indexed: 01/28/2023] Open
Abstract
Guanylate kinases (GKs), which convert guanosine monophosphate into guanosine diphosphate (GDP), are important for growth and mannose outer chain elongation of cell wall N-linked glycoproteins in yeast. Here, we identified the ortholog of Saccharomyces cerevisiae GK Guk1, named MoGuk1 and a novel family of fungal GKs MoGuk2 in the rice blast fungus Magnaporthe oryzae. MoGuk1 contains 242 aa with an C-terminal GuKc domain that very similar to yeast Guk1. MoGuk2 contains 810 amino acids with a C-terminal GuKc domain and an additional N-terminal efThoc1 domain. Expression of either MoGuk1 or MoGuk2 in heterozygote yeast guk1 mutant could increase its GDP level. To investigate the biological role of MoGuk1 and MoGuk2 in M. oryzae, the gene replacement vectors were constructed. We obtained the ΔMoguk2 but not ΔMoguk1 mutant by screening over 1,000 transformants, indicating MoGuk1 might be essential for M. oryzae. The ΔMoguk2 mutant showed weak reductions in vegetative growth, conidial germination, appressorial formation, and appressorial turgor, and showed significant reductions in sporulation and pathogenicity. Moreover, the ΔMoguk2 mutant failed to produce perithecia and was sensitive to neomycin and a mixture of neomycin-tunicamycin. Exogenous GDP and ATP partially rescued the defects in conidial germination, appressorial formation, and infectious growth of the mutant. Further analysis revealed that intracellular GDP and GTP level was decreased, and GMP level was increased in the mutant, suggesting that MoGuk2 exhibits enzymatic activity. Structural analysis proved that the efThoc1, GuKc, and P-loop domains are essential for the full function of MoGuk2. Taken together, our data suggest that the guanylate kinase MoGuk2 is involved in the de novo GTP biosynthesis pathway and is important for infection-related morphogenesis in the rice blast fungus.
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Affiliation(s)
- Xingjia Cai
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, China
| | - Xi Zhang
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, China
| | - Xinrui Li
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, China
| | - Muxing Liu
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, China
| | - Xinyu Liu
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, China
| | - Xiaoli Wang
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, China
| | - Haifeng Zhang
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, China
| | - Xiaobo Zheng
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, China
| | - Zhengguang Zhang
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, China
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27
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Yemelin A, Brauchler A, Jacob S, Laufer J, Heck L, Foster AJ, Antelo L, Andresen K, Thines E. Identification of factors involved in dimorphism and pathogenicity of Zymoseptoria tritici. PLoS One 2017; 12:e0183065. [PMID: 28829795 PMCID: PMC5568738 DOI: 10.1371/journal.pone.0183065] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 07/28/2017] [Indexed: 01/20/2023] Open
Abstract
A forward genetics approach was applied in order to investigate the molecular basis of morphological transition in the wheat pathogenic fungus Zymoseptoria tritici. Z. tritici is a dimorphic plant pathogen displaying environmentally regulated morphogenetic transition between yeast-like and hyphal growth. Considering the infection mode of Z. tritici, the switching to hyphal growth is essential for pathogenicity allowing the fungus the host invasion through natural openings like stomata. We exploited a previously developed Agrobacterium tumefaciens-mediated transformation (ATMT) to generate a mutant library by insertional mutagenesis including more than 10,000 random mutants. To identify genes involved in dimorphic switch, a plate-based screening system was established. With this approach eleven dimorphic switch deficient random mutants were recovered, ten of which exhibited a yeast-like mode of growth and one mutant predominantly growing filamentously, producing high amount of mycelium under different incubation conditions. Using genome walking approach previously established, the T-DNA integration sites were recovered and the disrupted genomic loci of corresponding mutants were identified and validated within reverse genetics approach. As prove of concept, two of the random mutants obtained were selected for further investigation using targeted gene inactivation. Both genes deduced were found to encode known factors, previously characterized in other fungi: Ssk1p being constituent of HOG pathway and Ade5,7p involved in de novo purine biosynthesis. The targeted mutant strains defective in these genes exhibit a drastically impaired virulence within infection assays on whole wheat plants. Moreover exploiting further physiological assays the predicted function for both gene products could be confirmed in concordance with conserved biological role of homologous proteins previously described in other fungal organisms.
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Affiliation(s)
- Alexander Yemelin
- Institute for Biotechnology and Drug Research (IBWF gGmbH), Kaiserslautern, Germany
| | - Annamaria Brauchler
- Institute of Molecular Physiology, Microbiology and Wine Research, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Stefan Jacob
- Institute for Biotechnology and Drug Research (IBWF gGmbH), Kaiserslautern, Germany
| | - Julian Laufer
- Institute for Biotechnology and Drug Research (IBWF gGmbH), Kaiserslautern, Germany
| | - Larissa Heck
- Institute for Biotechnology and Drug Research (IBWF gGmbH), Kaiserslautern, Germany
| | - Andrew J. Foster
- Institute for Biotechnology and Drug Research (IBWF gGmbH), Kaiserslautern, Germany
| | - Luis Antelo
- Institute of Molecular Physiology, Microbiology and Wine Research, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Karsten Andresen
- Institute of Molecular Physiology, Microbiology and Wine Research, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Eckhard Thines
- Institute for Biotechnology and Drug Research (IBWF gGmbH), Kaiserslautern, Germany
- Institute of Molecular Physiology, Microbiology and Wine Research, Johannes Gutenberg University Mainz, Mainz, Germany
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28
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Hagen F, Lumbsch HT, Arsic Arsenijevic V, Badali H, Bertout S, Billmyre RB, Bragulat MR, Cabañes FJ, Carbia M, Chakrabarti A, Chaturvedi S, Chaturvedi V, Chen M, Chowdhary A, Colom MF, Cornely OA, Crous PW, Cuétara MS, Diaz MR, Espinel-Ingroff A, Fakhim H, Falk R, Fang W, Herkert PF, Ferrer Rodríguez C, Fraser JA, Gené J, Guarro J, Idnurm A, Illnait-Zaragozi MT, Khan Z, Khayhan K, Kolecka A, Kurtzman CP, Lagrou K, Liao W, Linares C, Meis JF, Nielsen K, Nyazika TK, Pan W, Pekmezovic M, Polacheck I, Posteraro B, de Queiroz Telles F, Romeo O, Sánchez M, Sampaio A, Sanguinetti M, Sriburee P, Sugita T, Taj-Aldeen SJ, Takashima M, Taylor JW, Theelen B, Tomazin R, Verweij PE, Wahyuningsih R, Wang P, Boekhout T. Importance of Resolving Fungal Nomenclature: the Case of Multiple Pathogenic Species in the Cryptococcus Genus. mSphere 2017; 2:e00238-17. [PMID: 28875175 PMCID: PMC5577652 DOI: 10.1128/msphere.00238-17] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Cryptococcosis is a major fungal disease caused by members of the Cryptococcus gattii and Cryptococcus neoformans species complexes. After more than 15 years of molecular genetic and phenotypic studies and much debate, a proposal for a taxonomic revision was made. The two varieties within C. neoformans were raised to species level, and the same was done for five genotypes within C. gattii. In a recent perspective (K. J. Kwon-Chung et al., mSphere 2:e00357-16, 2017, https://doi.org/10.1128/mSphere.00357-16), it was argued that this taxonomic proposal was premature and without consensus in the community. Although the authors of the perspective recognized the existence of genetic diversity, they preferred the use of the informal nomenclature "C. neoformans species complex" and "C. gattii species complex." Here we highlight the advantage of recognizing these seven species, as ignoring these species will impede deciphering further biologically and clinically relevant differences between them, which may in turn delay future clinical advances.
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Affiliation(s)
- Ferry Hagen
- Department of Medical Microbiology and Infectious Diseases, Canisius-Wilhelmina Hospital, Nijmegen, The Netherlands
- Centre of Expertise in Mycology Radboudumc/CWZ, Nijmegen, The Netherlands
| | | | | | - Hamid Badali
- Department of Medical Mycology and Parasitology/Invasive Fungi Research Center (IFRC), Mazandaran University of Medical Sciences, Sari, Iran
| | - Sebastien Bertout
- Unité Mixte Internationale Recherches Translationnelles sur l’Infection à VIH et les Maladies Infectieuses, Laboratoire de Parasitologie et Mycologie Médicale, UFR Pharmacie, Université Montpellier, Montpellier, France
| | - R. Blake Billmyre
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, USA
| | - M. Rosa Bragulat
- Veterinary Mycology Group, Department of Animal Health and Anatomy, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain
| | - F. Javier Cabañes
- Veterinary Mycology Group, Department of Animal Health and Anatomy, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain
| | - Mauricio Carbia
- Departamento de Parasitología y Micología, Instituto de Higiene, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Arunaloke Chakrabarti
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Sudha Chaturvedi
- Mycology Laboratory, Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - Vishnu Chaturvedi
- Mycology Laboratory, Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - Min Chen
- Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Second Military Medical University, Shanghai, China
- Department of Dermatology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Anuradha Chowdhary
- Department of Medical Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, India
| | | | - Oliver A. Cornely
- CECAD Cluster of Excellence, University of Cologne, Cologne, Germany
- Department I for Internal Medicine, University Hospital of Cologne, Cologne, Germany
- Center for Clinical Trials, University Hospital Cologne, Cologne, Germany
| | - Pedro W. Crous
- Phytopathology Research, Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands
- Department of Entomology and Plant Pathology, Faculty of Agriculture, Chiang Mai University, Chiang Mai, Thailand
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Maria S. Cuétara
- Department of Microbiology, Hospital Severo Ochoa, Madrid, Spain
| | - Mara R. Diaz
- University of Miami, NSF NIEHS Oceans and Human Health Center, Miami, Florida, USA
- Rosentiel School of Marine and Atmospheric Science, Division of Marine Biology and Fisheries, University of Miami, Miami, Florida, USA
| | | | - Hamed Fakhim
- Department of Medical Parasitology and Mycology/Cellular and Molecular Research Center, Urmia University of Medical Sciences, Urmia, Iran
| | - Rama Falk
- Department of Clinical Microbiology and Infectious Diseases, Hadassah-Hebrew University Medical Center, Ein Kerem, Jerusalem, Israel
- Department of Fisheries and Aquaculture, Ministry of Agriculture and Rural Development, Nir-David, Israel
| | - Wenjie Fang
- Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Second Military Medical University, Shanghai, China
- Department of Dermatology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Patricia F. Herkert
- Department of Medical Microbiology and Infectious Diseases, Canisius-Wilhelmina Hospital, Nijmegen, The Netherlands
- Postgraduate Program in Microbiology, Parasitology and Pathology, Biological Sciences, Department of Basic Pathology, Federal University of Parana, Curitiba, Brazil
| | | | - James A. Fraser
- Australian Infectious Diseases Research Centre, School of Chemistry & Molecular Biosciences, University of Queensland, Brisbane, Australia
| | - Josepa Gené
- Unitat de Micologia, Facultat de Medicina i Ciències de la Salut, IISPV, Universitat Rovira i Virgili, Reus, Spain
| | - Josep Guarro
- Unitat de Micologia, Facultat de Medicina i Ciències de la Salut, IISPV, Universitat Rovira i Virgili, Reus, Spain
| | - Alexander Idnurm
- School of BioSciences, BioSciences 2, University of Melbourne, Melbourne, Australia
| | | | - Ziauddin Khan
- Department of Microbiology, Faculty of Medicine, Kuwait University, Safat, Kuwait
| | - Kantarawee Khayhan
- Department of Microbiology and Parasitology, Faculty of Medical Sciences, University of Phayao, Phayao, Thailand
- Yeast Research, Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands
| | - Anna Kolecka
- Yeast Research, Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands
| | - Cletus P. Kurtzman
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, USDA-ARS, Peoria, Illinois, USA
| | - Katrien Lagrou
- Department of Laboratory Medicine, University Hospitals Leuven, Leuven, Belgium
- Department of Microbiology and Immunology, KU Leuven - University of Leuven, Leuven, Belgium
| | - Wanqing Liao
- Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Second Military Medical University, Shanghai, China
- Department of Dermatology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Carlos Linares
- Medical School, Universidad Miguel Hernández, Alicante, Spain
| | - Jacques F. Meis
- Department of Medical Microbiology and Infectious Diseases, Canisius-Wilhelmina Hospital, Nijmegen, The Netherlands
- Centre of Expertise in Mycology Radboudumc/CWZ, Nijmegen, The Netherlands
| | - Kirsten Nielsen
- Department of Microbiology and Immunology, University of Minnesota, Minneapolis, Minnesota, USA
| | - Tinashe K. Nyazika
- Department of Medical Microbiology, College of Health Sciences, University of Zimbabwe, Harare, Zimbabwe
- Malawi-Liverpool-Wellcome Trust, College of Medicine, University of Malawi, Blantyre, Malawi
- School of Tropical Medicine, Liverpool, United Kingdom
| | - Weihua Pan
- Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Second Military Medical University, Shanghai, China
- Department of Dermatology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | | | - Itzhack Polacheck
- Department of Clinical Microbiology and Infectious Diseases, Hadassah-Hebrew University Medical Center, Ein Kerem, Jerusalem, Israel
| | - Brunella Posteraro
- Institute of Public Health (Section of Hygiene), Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario Agostino Gemelli, Rome, Italy
| | - Flavio de Queiroz Telles
- Department of Communitarian Health, Hospital de Clínicas, Federal University of Parana, Curitiba, Brazil
| | - Orazio Romeo
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy
- IRCCS Centro Neurolesi Bonino-Pulejo, Messina, Italy
| | - Manuel Sánchez
- Medical School, Universidad Miguel Hernández, Alicante, Spain
| | - Ana Sampaio
- Centro de Investigação e de Tecnologias Agro-ambientais e Biológicas (CITAB), Universidade de Trás-os-Montes e Alto Douro (UTAD), Quinta dos Prados, Vila Real, Portugal
| | - Maurizio Sanguinetti
- Institute of Microbiology, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario Agostino Gemelli, Rome, Italy
| | - Pojana Sriburee
- Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Takashi Sugita
- Department of Microbiology, Meiji Pharmaceutical University, Noshio, Kiyose, Tokyo, Japan
| | - Saad J. Taj-Aldeen
- Mycology Unit, Microbiology Division, Department of Laboratory Medicine and Pathology, Hamad Medical Corporation, Doha, Qatar
| | - Masako Takashima
- Japan Collection of Microorganisms, RIKEN BioResource Center, Koyadai, Tsukuba, Ibaraki, Japan
| | - John W. Taylor
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, California, USA
| | - Bart Theelen
- Yeast Research, Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands
| | - Rok Tomazin
- Institute of Microbiology and Immunology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Paul E. Verweij
- Centre of Expertise in Mycology Radboudumc/CWZ, Nijmegen, The Netherlands
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Retno Wahyuningsih
- Department of Parasitology, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia
- Department of Parasitology, School of Medicine, Universitas Kristen Indonesia, Jakarta, Indonesia
| | - Ping Wang
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana, USA
- Department of Pediatrics, Louisiana State University Health Sciences Center, New Orleans, Louisiana, USA
| | - Teun Boekhout
- Institute of Biodiversity and Ecosystems Dynamics (IBED), University of Amsterdam, Amsterdam, The Netherlands
- Yeast Research, Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands
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Chitty JL, Fraser JA. Purine Acquisition and Synthesis by Human Fungal Pathogens. Microorganisms 2017; 5:microorganisms5020033. [PMID: 28594372 PMCID: PMC5488104 DOI: 10.3390/microorganisms5020033] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 06/06/2017] [Accepted: 06/06/2017] [Indexed: 01/13/2023] Open
Abstract
While members of the Kingdom Fungi are found across many of the world's most hostile environments, only a limited number of species can thrive within the human host. The causative agents of the most common invasive fungal infections are Candida albicans, Aspergillus fumigatus, and Cryptococcus neoformans. During the infection process, these fungi must not only combat the host immune system while adapting to dramatic changes in temperature and pH, but also acquire sufficient nutrients to enable growth and dissemination in the host. One class of nutrients required by fungi, which is found in varying concentrations in their environmental niches and the human host, is the purines. These nitrogen-containing heterocycles are one of the most abundant organic molecules in nature and are required for roles as diverse as signal transduction, energy metabolism and DNA synthesis. The most common life-threatening fungal pathogens can degrade, salvage and synthesize de novo purines through a number of enzymatic steps that are conserved. While these enable them to adapt to the changing purine availability in the environment, only de novo purine biosynthesis is essential during infection and therefore an attractive antimycotic target.
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Affiliation(s)
- Jessica L Chitty
- Australian Infectious Diseases Research Centre, School of Chemistry & Molecular Biosciences, the University of Queensland, St Lucia, Queensland 4072, Australia.
- Institute for Molecular Bioscience, the University of Queensland, St Lucia, Queensland 4072, Australia.
| | - James A Fraser
- Australian Infectious Diseases Research Centre, School of Chemistry & Molecular Biosciences, the University of Queensland, St Lucia, Queensland 4072, Australia.
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Chitty JL, Blake KL, Blundell RD, Koh YQAE, Thompson M, Robertson AAB, Butler MS, Cooper MA, Kappler U, Williams SJ, Kobe B, Fraser JA. Cryptococcus neoformans ADS lyase is an enzyme essential for virulence whose crystal structure reveals features exploitable in antifungal drug design. J Biol Chem 2017; 292:11829-11839. [PMID: 28559277 DOI: 10.1074/jbc.m117.787994] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 05/03/2017] [Indexed: 01/09/2023] Open
Abstract
There is significant clinical need for new antifungal agents to manage infections with pathogenic species such as Cryptococcus neoformans Because the purine biosynthesis pathway is essential for many metabolic processes, such as synthesis of DNA and RNA and energy generation, it may represent a potential target for developing new antifungals. Within this pathway, the bifunctional enzyme adenylosuccinate (ADS) lyase plays a role in the formation of the key intermediates inosine monophosphate and AMP involved in the synthesis of ATP and GTP, prompting us to investigate ADS lyase in C. neoformans. Here, we report that ADE13 encodes ADS lyase in C. neoformans. We found that an ade13Δ mutant is an adenine auxotroph and is unable to successfully cause infections in a murine model of virulence. Plate assays revealed that production of a number of virulence factors essential for dissemination and survival of C. neoformans in a host environment was compromised even with the addition of exogenous adenine. Purified recombinant C. neoformans ADS lyase shows catalytic activity similar to its human counterpart, and its crystal structure, the first fungal ADS lyase structure determined, shows a high degree of structural similarity to that of human ADS lyase. Two potentially important amino acid differences are identified in the C. neoformans crystal structure, in particular a threonine residue that may serve as an additional point of binding for a fungal enzyme-specific inhibitor. Besides serving as an antimicrobial target, C. neoformans ADS lyase inhibitors may also serve as potential therapeutics for metabolic disease; rather than disrupt ADS lyase, compounds that improve the stability the enzyme may be used to treat ADS lyase deficiency disease.
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Affiliation(s)
- Jessica L Chitty
- Australian Infectious Diseases Research Centre, School of Chemistry & Molecular Biosciences, University of Queensland, St. Lucia, Queensland 4072; Institute for Molecular Bioscience, University of Queensland, St. Lucia, Queensland 4072
| | - Kirsten L Blake
- Australian Infectious Diseases Research Centre, School of Chemistry & Molecular Biosciences, University of Queensland, St. Lucia, Queensland 4072
| | - Ross D Blundell
- Australian Infectious Diseases Research Centre, School of Chemistry & Molecular Biosciences, University of Queensland, St. Lucia, Queensland 4072
| | - Y Q Andre E Koh
- Australian Infectious Diseases Research Centre, School of Chemistry & Molecular Biosciences, University of Queensland, St. Lucia, Queensland 4072
| | - Merinda Thompson
- Australian Infectious Diseases Research Centre, School of Chemistry & Molecular Biosciences, University of Queensland, St. Lucia, Queensland 4072
| | - Avril A B Robertson
- Institute for Molecular Bioscience, University of Queensland, St. Lucia, Queensland 4072
| | - Mark S Butler
- Institute for Molecular Bioscience, University of Queensland, St. Lucia, Queensland 4072
| | - Matthew A Cooper
- Australian Infectious Diseases Research Centre, School of Chemistry & Molecular Biosciences, University of Queensland, St. Lucia, Queensland 4072; Institute for Molecular Bioscience, University of Queensland, St. Lucia, Queensland 4072
| | - Ulrike Kappler
- Australian Infectious Diseases Research Centre, School of Chemistry & Molecular Biosciences, University of Queensland, St. Lucia, Queensland 4072; Centre for Metals in Biology, University of Queensland, St. Lucia, Queensland 4072
| | - Simon J Williams
- Australian Infectious Diseases Research Centre, School of Chemistry & Molecular Biosciences, University of Queensland, St. Lucia, Queensland 4072; Research School of Biology, Australian National University, Acton, Australian Capital Territory 2601 Australia
| | - Bostjan Kobe
- Australian Infectious Diseases Research Centre, School of Chemistry & Molecular Biosciences, University of Queensland, St. Lucia, Queensland 4072; Institute for Molecular Bioscience, University of Queensland, St. Lucia, Queensland 4072
| | - James A Fraser
- Australian Infectious Diseases Research Centre, School of Chemistry & Molecular Biosciences, University of Queensland, St. Lucia, Queensland 4072.
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Hu J, Ma L, Wang H, Yan H, Zhang D, Li Z, Jiang J, Li Y. A novel benzo-heterocyclic amine derivative N30 inhibits influenza virus replication by depression of Inosine-5'-Monophospate Dehydrogenase activity. Virol J 2017; 14:55. [PMID: 28298229 PMCID: PMC5353780 DOI: 10.1186/s12985-017-0724-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2016] [Accepted: 03/07/2017] [Indexed: 01/02/2023] Open
Abstract
BACKGROUD Influenza virus is still a huge threat to the world-wide public health. Host inosine-5'- monophosphate dehydrogenase (IMPDH) involved in the synthesis of guanine nucleotides, is known to be a potential target to inhibit the replication of viruses. Herein, we evaluated antiviral activity of a benzo-heterocyclic amine derivative N30, which was designed to inhibit IMPDH. RESULTS The results demonstrated that N30 inhibited the replication of H1N1, H3N2, influenza B viruses, including oseltamivir and amantadine resistant strains in vitro. Mechanistically, neuraminidase inhibition assay and hemagglutination inhibition assay suggested that N30 did not directly target the two envelope glycoproteins required for viral adsorption or release. Instead, the compound could depress the activity of IMPDH type II. Based on these findings, we further confirmed that N30 provided a strong inhibition on the replication of respiratory syncytial virus, coronavirus, enterovirus 71 and a diverse strains of coxsackie B virus. CONCLUSIONS We identified the small molecule N30, as an inhibitor of IMPDH, might be a potential candidate to inhibit the replication of various viruses.
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Affiliation(s)
- Jin Hu
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Linlin Ma
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Huiqiang Wang
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Haiyan Yan
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Dajun Zhang
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Zhuorong Li
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Jiandong Jiang
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yuhuan Li
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
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Chitty JL, Tatzenko TL, Williams SJ, Koh YQAE, Corfield EC, Butler MS, Robertson AAB, Cooper MA, Kappler U, Kobe B, Fraser JA. GMP Synthase Is Required for Virulence Factor Production and Infection by Cryptococcus neoformans. J Biol Chem 2017; 292:3049-3059. [PMID: 28062578 DOI: 10.1074/jbc.m116.767533] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 01/04/2017] [Indexed: 11/06/2022] Open
Abstract
Over the last four decades the HIV pandemic and advances in medical treatments that also cause immunosuppression have produced an ever-growing cohort of individuals susceptible to opportunistic pathogens. Of these, AIDS patients are particularly vulnerable to infection by the encapsulated yeast Cryptococcus neoformans Most commonly found in the environment in purine-rich bird guano, C. neoformans experiences a drastic change in nutrient availability during host infection, ultimately disseminating to colonize the purine-poor central nervous system. Investigating the consequences of this challenge, we have characterized C. neoformans GMP synthase, the second enzyme in the guanylate branch of de novo purine biosynthesis. We show that in the absence of GMP synthase, C. neoformans becomes a guanine auxotroph, the production of key virulence factors is compromised, and the ability to infect nematodes and mice is abolished. Activity assays performed using recombinant protein unveiled differences in substrate binding between the C. neoformans and human enzymes, with structural insights into these kinetic differences acquired via homology modeling. Collectively, these data highlight the potential of GMP synthase to be exploited in the development of new therapeutic agents for the treatment of disseminated, life-threatening fungal infections.
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Affiliation(s)
- Jessica L Chitty
- From the Australian Infectious Diseases Research Centre, School of Chemistry & Molecular Biosciences.,the Institute for Molecular Bioscience, and
| | - Tayla L Tatzenko
- From the Australian Infectious Diseases Research Centre, School of Chemistry & Molecular Biosciences
| | - Simon J Williams
- From the Australian Infectious Diseases Research Centre, School of Chemistry & Molecular Biosciences.,the ANU Research School of Biology, Australian National University, Acton, ACT 2601, Australia
| | - Y Q Andre E Koh
- From the Australian Infectious Diseases Research Centre, School of Chemistry & Molecular Biosciences
| | - Elizabeth C Corfield
- From the Australian Infectious Diseases Research Centre, School of Chemistry & Molecular Biosciences
| | | | | | - Matthew A Cooper
- From the Australian Infectious Diseases Research Centre, School of Chemistry & Molecular Biosciences.,the Institute for Molecular Bioscience, and
| | - Ulrike Kappler
- From the Australian Infectious Diseases Research Centre, School of Chemistry & Molecular Biosciences.,the Centre for Metals in Biology, University of Queensland, St. Lucia, Queensland 4072, Australia and
| | - Bostjan Kobe
- From the Australian Infectious Diseases Research Centre, School of Chemistry & Molecular Biosciences.,the Institute for Molecular Bioscience, and
| | - James A Fraser
- From the Australian Infectious Diseases Research Centre, School of Chemistry & Molecular Biosciences,
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Banerjee D, Umland TC, Panepinto JC. De Novo Pyrimidine Biosynthesis Connects Cell Integrity to Amphotericin B Susceptibility in Cryptococcus neoformans. mSphere 2016; 1:e00191-16. [PMID: 27904878 PMCID: PMC5112334 DOI: 10.1128/msphere.00191-16] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 10/24/2016] [Indexed: 11/20/2022] Open
Abstract
The use of amphotericin B (AmB) in conjunction with 5-fluorocytosine (5-FC) is known to be the optimal therapy for treating cryptococcosis, but the mechanism by which 5-FC synergizes with AmB is unknown. In this study, we generated a Cryptococcus neoformans ura1Δ mutant lacking dihydroorotate dehydrogenase (DHODH), which demonstrated temperature-sensitive growth due to a defect in cell integrity and sensitivity to cell wall-damaging agents. In addition, sensitivity to AmB was greatly increased. Inclusion of uracil or uridine in the medium did not suppress the cell wall or AmB phenotype, whereas complementation with the wild-type URA1 gene complemented the mutant phenotype. As a measure of membrane accessibility, we assayed the rate of association of the lipid-binding dye 3,3'-dihexyloxacarbocyanine iodide (DiOC6) and saw more rapid association in the ura1Δ mutant. We likewise saw an increased rate of DiOC6 association in other AmB-sensitive mutants, including a ura- spontaneous URA5 mutant made by 5-fluoroorotic acid (5-FOA) selection and a bck1Δ mutant defective in cell integrity signaling. Similar results were also obtained by using a specific plasma membrane-binding CellMask live stain, with cell integrity mutants that exhibited increased and faster association of the dye with the membrane. Chitin synthase mutants (chs5Δ and chs6Δ) that lack any reported cell wall defects, in turn, demonstrate neither any increased susceptibility to AmB nor a greater accessibility to either of the dyes. Finally, perturbation of the cell wall of the wild type by treatment with the β-1,6-glucan synthase inhibitor caspofungin was synergistic with AmB in vitro. IMPORTANCE Synergy between AmB and nucleotide biosynthetic pathways has been documented, but the mechanism of this interaction has not been delineated. Results from this study suggest a correlation between uridine nucleotide biosynthesis and cell integrity likely mediated through the pool of nucleotide-sugar conjugates, which are precursor molecules for both capsule and cell wall of C. neoformans. Thus, we propose a mechanism by which structural defects in the cell wall resulting from perturbation of pyrimidine biosynthesis allow faster and increased penetration of AmB molecules into the cell membrane. Overall, our work demonstrates that impairment of pyrimidine biosynthesis in C. neoformans could be a potential target for antifungal therapy, either alone or in combination with AmB.
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Affiliation(s)
- Dithi Banerjee
- Department of Microbiology and Immunology, Witebsky Center for Microbial Pathogenesis and Immunology, University at Buffalo, The State University of New York, Buffalo, New York, USA
| | - Timothy C. Umland
- Department of Structural Biology, Hauptman Woodward Medical Research Institute, University at Buffalo, The State University of New York, Buffalo, New York, USA
| | - John C. Panepinto
- Department of Microbiology and Immunology, Witebsky Center for Microbial Pathogenesis and Immunology, University at Buffalo, The State University of New York, Buffalo, New York, USA
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Blundell RD, Williams SJ, Arras SDM, Chitty JL, Blake KL, Ericsson DJ, Tibrewal N, Rohr J, Koh YQAE, Kappler U, Robertson AAB, Butler MS, Cooper MA, Kobe B, Fraser JA. Disruption of de Novo Adenosine Triphosphate (ATP) Biosynthesis Abolishes Virulence in Cryptococcus neoformans. ACS Infect Dis 2016; 2:651-663. [PMID: 27759389 DOI: 10.1021/acsinfecdis.6b00121] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Opportunistic fungal pathogens such as Cryptococcus neoformans are a growing cause of morbidity and mortality among immunocompromised populations worldwide. To address the current paucity of antifungal therapeutic agents, further research into fungal-specific drug targets is required. Adenylosuccinate synthetase (AdSS) is a crucial enzyme in the adeosine triphosphate (ATP) biosynthetic pathway, catalyzing the formation of adenylosuccinate from inosine monophosphate and aspartate. We have investigated the potential of this enzyme as an antifungal drug target, finding that loss of function results in adenine auxotrophy in C. neoformans, as well as complete loss of virulence in a murine model. Cryptococcal AdSS was expressed and purified in Escherichia coli and the enzyme's crystal structure determined, the first example of a structure of this enzyme from fungi. Together with enzyme kinetic studies, this structural information enabled comparison of the fungal enzyme with the human orthologue and revealed species-specific differences potentially exploitable via rational drug design. These results validate AdSS as a promising antifungal drug target and lay a foundation for future in silico and in vitro screens for novel antifungal compounds.
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Affiliation(s)
- Ross D. Blundell
- Australian Infectious Diseases Research
Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Simon J. Williams
- Australian Infectious Diseases Research
Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
- Institute for Molecular
Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Samantha D. M. Arras
- Australian Infectious Diseases Research
Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Jessica L. Chitty
- Australian Infectious Diseases Research
Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Kirsten L. Blake
- Australian Infectious Diseases Research
Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Daniel J. Ericsson
- Australian Infectious Diseases Research
Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
- Institute for Molecular
Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
- MX Beamlines, Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria 3168, Australia
| | - Nidhi Tibrewal
- College of Pharmacy, University of Kentucky, Lexington, Kentucky 40536-0596, United States
| | - Jurgen Rohr
- College of Pharmacy, University of Kentucky, Lexington, Kentucky 40536-0596, United States
| | - Y. Q. Andre E. Koh
- Australian Infectious Diseases Research
Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Ulrike Kappler
- Australian Infectious Diseases Research
Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
- Centre for Metals in Biology, School of
Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Avril A. B. Robertson
- Institute for Molecular
Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Mark S. Butler
- Institute for Molecular
Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Matthew A. Cooper
- Institute for Molecular
Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Bostjan Kobe
- Australian Infectious Diseases Research
Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
- Institute for Molecular
Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - James A. Fraser
- Australian Infectious Diseases Research
Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
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35
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De Novo Guanine Biosynthesis but Not the Riboswitch-Regulated Purine Salvage Pathway Is Required for Staphylococcus aureus Infection In Vivo. J Bacteriol 2016; 198:2001-2015. [PMID: 27161118 DOI: 10.1128/jb.00051-16] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 05/05/2016] [Indexed: 12/26/2022] Open
Abstract
UNLABELLED De novo guanine biosynthesis is an evolutionarily conserved pathway that creates sufficient nucleotides to support DNA replication, transcription, and translation. Bacteria can also salvage nutrients from the environment to supplement the de novo pathway, but the relative importance of either pathway during Staphylococcus aureus infection is not known. In S. aureus, genes important for both de novo and salvage pathways are regulated by a guanine riboswitch. Bacterial riboswitches have attracted attention as a novel class of antibacterial drug targets because they have high affinity for small molecules, are absent in humans, and regulate the expression of multiple genes, including those essential for cell viability. Genetic and biophysical methods confirm the existence of a bona fide guanine riboswitch upstream of an operon encoding xanthine phosphoribosyltransferase (xpt), xanthine permease (pbuX), inosine-5'-monophosphate dehydrogenase (guaB), and GMP synthetase (guaA) that represses the expression of these genes in response to guanine. We found that S. aureus guaB and guaA are also transcribed independently of riboswitch control by alternative promoter elements. Deletion of xpt-pbuX-guaB-guaA genes resulted in guanine auxotrophy, failure to grow in human serum, profound abnormalities in cell morphology, and avirulence in mouse infection models, whereas deletion of the purine salvage genes xpt-pbuX had none of these effects. Disruption of guaB or guaA recapitulates the xpt-pbuX-guaB-guaA deletion in vivo In total, the data demonstrate that targeting the guanine riboswitch alone is insufficient to treat S. aureus infections but that inhibition of guaA or guaB could have therapeutic utility. IMPORTANCE De novo guanine biosynthesis and purine salvage genes were reported to be regulated by a guanine riboswitch in Staphylococcus aureus We demonstrate here that this is not true, because alternative promoter elements that uncouple the de novo pathway from riboswitch regulation were identified. We found that in animal models of infection, the purine salvage pathway is insufficient for S. aureus survival in the absence of de novo guanine biosynthesis. These data suggest targeting the de novo guanine biosynthesis pathway may have therapeutic utility in the treatment of S. aureus infections.
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36
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Ishii M, Matsumoto Y, Sekimizu K. Usefulness of silkworm as a host animal for understanding pathogenicity of Cryptococcus neoformans. Drug Discov Ther 2016; 10:9-13. [PMID: 26902902 DOI: 10.5582/ddt.2016.01015] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
We propose Cryptococcus neoformans infection model using silkworm for understanding cryptococcosis and screening of therapeutically effective antibiotics. Silkworm is an insect whose rearing methods were established through a long history of the sericulture industry. Silkworm facilitates experiments using a large number of individuals because of low cost for rearing and few ethical problems caused by killing animals. Silkworm can be reared at 37˚C to perform infection experiments at same temperature to human body. Injection of accurate amounts of samples into hemolymph of silkworm by usual syringes is easy to be done since silkworm has an appropriate size to handle. Moreover two injection methods, injection into hemolymph and intestine, are distinguishable for silkworms. The former is correspondent to intravenous injection, and the latter is to oral administration in humans. Taking these advantages of silkworms as host animals, it is possible to evaluate the virulence factors in C. neoformans and the therapeutic efficacy of antifungal agents.
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Affiliation(s)
- Masaki Ishii
- Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo
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Surekha K, Prabhu D, Richard M, Nachiappan M, Biswal J, Jeyakanthan J. Investigation of vital pathogenic target orotate phosphoribosyltransferases (OPRTase) from Thermus thermophilus HB8: Phylogenetic and molecular modeling approach. Gene 2016; 583:102-111. [PMID: 26861612 DOI: 10.1016/j.gene.2016.02.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 01/16/2016] [Accepted: 02/05/2016] [Indexed: 01/28/2023]
Abstract
Biosynthesis pathways of pyrimidine and purine are shown to play an important role in regular cellular activities. The biosynthesis can occur either through de novo or salvage pathways based on the requirement of the cell. The pyrimidine biosynthesis pathway has been linked to several disorders and various autoimmune diseases. Orotate phosphoribosyl transferase (OPRTase) is an important enzyme which catalyzes the conversion of orotate to orotate monophosphate in the fifth step of pyrimidine biosynthesis. Phylogenetic analysis of 228 OPRTase sequences shows the distribution of proteins across different living forms of life. High structural similarities between Thermusthermophilus and other organisms kindled us to concentrate on OPRTase as an anti-pathogenic target. In this study, a homology model of OPRTase was constructed using 2P1Z as a template. About 100 ns molecular dynamics simulation was performed to investigate the conformational stability and dynamic patterns of the protein. The amino acid residues (Met1, Asp2, Glu43, Ala44, Glu47, Lys51, Ala157 and Leu158) lining in the binding site were predicted using SiteMap. Further, structure based virtual screening was performed on the predicted binding site using ChemBridge, Asinex, Binding, NCI, TosLab and Zinc databases. Compounds retrieved from the screening collections were manually clustered. The resultant protein-ligand complexes were subjected to molecular dynamics simulations, which further validates the binding modes of the hits. The study may provide better insight for designing potent anti-pathogenic agent.
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Affiliation(s)
- Kanagarajan Surekha
- Room No. 402, Structural Biology and Biocomputing Lab, Department of Bioinformatics, Alagappa University, Science Campus, Karaikudi 630004, India
| | - Damodharan Prabhu
- Room No. 402, Structural Biology and Biocomputing Lab, Department of Bioinformatics, Alagappa University, Science Campus, Karaikudi 630004, India
| | - Mariadasse Richard
- Room No. 402, Structural Biology and Biocomputing Lab, Department of Bioinformatics, Alagappa University, Science Campus, Karaikudi 630004, India
| | - Mutharasappan Nachiappan
- Room No. 402, Structural Biology and Biocomputing Lab, Department of Bioinformatics, Alagappa University, Science Campus, Karaikudi 630004, India
| | - Jayashree Biswal
- Room No. 402, Structural Biology and Biocomputing Lab, Department of Bioinformatics, Alagappa University, Science Campus, Karaikudi 630004, India
| | - Jeyaraman Jeyakanthan
- Room No. 402, Structural Biology and Biocomputing Lab, Department of Bioinformatics, Alagappa University, Science Campus, Karaikudi 630004, India.
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38
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Pérez-Torrado R, Querol A. Opportunistic Strains of Saccharomyces cerevisiae: A Potential Risk Sold in Food Products. Front Microbiol 2016; 6:1522. [PMID: 26779173 PMCID: PMC4705302 DOI: 10.3389/fmicb.2015.01522] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 12/17/2015] [Indexed: 12/28/2022] Open
Abstract
In recent decades, fungal infections have emerged as an important health problem associated with more people who present deficiencies in the immune system, such as HIV or transplanted patients. Saccharomyces cerevisiae is one of the emerging fungal pathogens with a unique characteristic: its presence in many food products. S. cerevisiae has an impeccably good food safety record compared to other microorganisms like virus, bacteria and some filamentous fungi. However, humans unknowingly and inadvertently ingest large viable populations of S. cerevisiae (home-brewed beer or dietary supplements that contain yeast). In the last few years, researchers have studied the nature of S. cerevisiae strains and the molecular mechanisms related to infections. Here we review the last advance made in this emerging pathogen and we discuss the implication of using this species in food products.
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Affiliation(s)
- Roberto Pérez-Torrado
- Food Biotechnology Department, Instituto de Agroquímica y Tecnología de los Alimentos - Consejo Superior de Investigaciones Científicas Valencia, Spain
| | - Amparo Querol
- Food Biotechnology Department, Instituto de Agroquímica y Tecnología de los Alimentos - Consejo Superior de Investigaciones Científicas Valencia, Spain
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Fialho MB, de Andrade A, Bonatto JMC, Salvato F, Labate CA, Pascholati SF. Proteomic response of the phytopathogen Phyllosticta citricarpa to antimicrobial volatile organic compounds from Saccharomyces cerevisiae. Microbiol Res 2015; 183:1-7. [PMID: 26805613 DOI: 10.1016/j.micres.2015.11.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 10/07/2015] [Accepted: 11/11/2015] [Indexed: 11/26/2022]
Abstract
Volatile organic compounds (VOCs) released by Saccharomyces cerevisiae inhibit plant pathogens, including the filamentous fungus Phyllosticta citricarpa, causal agent of citrus black spot. VOCs mediate relevant interactions between organisms in nature, and antimicrobial VOCs are promising, environmentally safer fumigants to control phytopathogens. As the mechanisms by which VOCs inhibit microorganisms are not well characterized, we evaluated the proteomic response in P. citricarpa after exposure for 12h to a reconstituted mixture of VOCs (alcohols and esters) originally identified in S. cerevisiae. Total protein was extracted and separated by 2D-PAGE, and differentially expressed proteins were identified by LC-MS/MS. About 600 proteins were detected, of which 29 were downregulated and 11 were upregulated. These proteins are involved in metabolism, genetic information processing, cellular processes, and transport. Enzymes related to energy-generating pathways, particularly glycolysis and the tricarboxylic acid cycle, were the most strongly affected. Thus, the data indicate that antimicrobial VOCs interfere with essential metabolic pathways in P. citricarpa to prevent fungal growth.
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Affiliation(s)
- Mauricio Batista Fialho
- Departamento de Fitopatologia e Nematologia, Escola Superior de Agricultura "Luiz de Queiroz" (ESALQ), Universidade de São Paulo (USP), Avenida Pádua Dias, 11, CP 09, CEP 13418-900 Piracicaba, SP, Brazil
| | - Alexander de Andrade
- Departamento de Genética, Escola Superior de Agricultura "Luiz de Queiroz" (ESALQ), Universidade de São Paulo (USP), Avenida Pádua Dias, 11, CP 09, CEP 13418-900 Piracicaba, SP, Brazil
| | - José Matheus Camargo Bonatto
- Departamento de Genética, Escola Superior de Agricultura "Luiz de Queiroz" (ESALQ), Universidade de São Paulo (USP), Avenida Pádua Dias, 11, CP 09, CEP 13418-900 Piracicaba, SP, Brazil
| | - Fernanda Salvato
- Departamento de Genética, Escola Superior de Agricultura "Luiz de Queiroz" (ESALQ), Universidade de São Paulo (USP), Avenida Pádua Dias, 11, CP 09, CEP 13418-900 Piracicaba, SP, Brazil
| | - Carlos Alberto Labate
- Departamento de Genética, Escola Superior de Agricultura "Luiz de Queiroz" (ESALQ), Universidade de São Paulo (USP), Avenida Pádua Dias, 11, CP 09, CEP 13418-900 Piracicaba, SP, Brazil
| | - Sérgio Florentino Pascholati
- Departamento de Fitopatologia e Nematologia, Escola Superior de Agricultura "Luiz de Queiroz" (ESALQ), Universidade de São Paulo (USP), Avenida Pádua Dias, 11, CP 09, CEP 13418-900 Piracicaba, SP, Brazil.
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Buey RM, Ledesma-Amaro R, Balsera M, de Pereda JM, Revuelta JL. Increased riboflavin production by manipulation of inosine 5'-monophosphate dehydrogenase in Ashbya gossypii. Appl Microbiol Biotechnol 2015; 99:9577-89. [PMID: 26150243 DOI: 10.1007/s00253-015-6710-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 05/15/2015] [Accepted: 05/19/2015] [Indexed: 12/13/2022]
Abstract
Guanine nucleotides are the precursors of essential biomolecules including nucleic acids and vitamins such as riboflavin. The enzyme inosine-5'-monophosphate dehydrogenase (IMPDH) catalyzes the ratelimiting step in the guanine nucleotide de novo biosynthetic pathway and plays a key role in controlling the cellular nucleotide pools. Thus, IMPDH is an important metabolic bottleneck in the guanine nucleotide synthesis, susceptible of manipulation by means of metabolic engineering approaches. Herein, we report the functional and structural characterization of the IMPDH enzyme from the industrial fungus Ashbya gossypii. Our data show that the overexpression of the IMPDH gene increases the metabolic flux through the guanine pathway and ultimately enhances 40 % riboflavin production with respect to the wild type. Also, IMPDH disruption results in a 100-fold increase of inosine excretion to the culture media. Our results contribute to the developing metabolic engineering toolbox aiming at improving the production of metabolites with biotechnological interest in A. gossypii.
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Affiliation(s)
- Rubén M Buey
- Metabolic Engineering Group, Departamento de Microbiología y Genética, Universidad de Salamanca, Edificio Departamental, Campus Miguel de Unamuno, 37007, Salamanca, Spain.
| | | | - Mónica Balsera
- Department Abiotic Stress, Instituto de Recursos Naturales y Agrobiología, Consejo Superior de Investigaciones Científicas, C/ Cordel de Merinas 40-52, 37008, Salamanca, Spain
| | - José María de Pereda
- Instituto de Biología Celular y Molecular del Cáncer, Consejo Superior de Investigaciones Científicas, Universidad de Salamanca, Campus Miguel de Unamuno, 37007, Salamanca, Spain
| | - José Luis Revuelta
- Metabolic Engineering Group, Departamento de Microbiología y Genética, Universidad de Salamanca, Edificio Departamental, Campus Miguel de Unamuno, 37007, Salamanca, Spain.
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Idnurm A, Lin X. Rising to the challenge of multiple Cryptococcus species and the diseases they cause. Fungal Genet Biol 2015; 78:1-6. [PMID: 25983191 DOI: 10.1016/j.fgb.2015.05.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 05/05/2015] [Accepted: 05/06/2015] [Indexed: 12/28/2022]
Abstract
Cryptococcus neoformans and Cryptococcus gattii are well-studied basidiomyceteous yeasts that are capable of causing disease in healthy and immunocompromised people. The Conference on Cryptococcus and Cryptococcosis (ICCC) is held every three years: the accompanying Special Issue stems from the 9th ICCC and covers a subset of the topics related to these fungi in detail. This conference started with a revised and reduced estimate of disease burden globally, in part due to improved treatment for HIV(+) people. However, mortality from cryptococcosis remains consistently high for those unfortunate to have limited access to therapies or without underlying immunodeficiencies. As such, there are yet still great distances to be covered to address antifungal drug availability, the need for new antifungal agents and the timing and doses of these agents in conjunction with antiviral therapy, underscoring the importance of continued research. A notable point from the 9th ICCC was the research addressing the variation in the pathogen and host populations. Analysis of cryptococcal strain variability, particularly at the molecular level, has resolved distinct lineages with the consequence of a taxonomic revision that divides C. neoformans and C. gattii into seven Cryptococcus species. Similarly, analysis of host factors in so called "immune-competent" individuals revealed previously unrecognized risk factors. Research on these species has established them as important model organisms to understand gene evolution and function in other fungi and eukaryotes. The stage is set for the refinement of research directions, leading ultimately to better treatment of this monophyletic clade of pathogens in the genus Cryptococcus.
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Affiliation(s)
- Alexander Idnurm
- School of BioSciences, University of Melbourne, VIC 3010, Australia.
| | - Xiaorong Lin
- Department of Biology, Texas A&M University, College Station, TX 77843, USA.
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Pérez-Torrado R, Llopis S, Perrone B, Gómez-Pastor R, Hube B, Querol A. Comparative genomic analysis reveals a critical role of de novo nucleotide biosynthesis for Saccharomyces cerevisiae virulence. PLoS One 2015; 10:e0122382. [PMID: 25816288 PMCID: PMC4376706 DOI: 10.1371/journal.pone.0122382] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 02/23/2015] [Indexed: 12/22/2022] Open
Abstract
In recent years, the number of human infection cases produced by the food related species Saccharomyces cerevisiae has increased. Whereas many strains of this species are considered safe, other 'opportunistic' strains show a high degree of potential virulence attributes and can cause infections in immunocompromised patients. Here we studied the genetic characteristics of selected opportunistic strains isolated from dietary supplements and also from patients by array comparative genomic hybridization. Our results show increased copy numbers of IMD genes in opportunistic strains, which are implicated in the de novo biosynthesis of the purine nucleotides pathway. The importance of this pathway for virulence of S. cerevisiae was confirmed by infections in immunodeficient murine models using a GUA1 mutant, a key gene of this pathway. We show that exogenous guanine, an end product of this pathway in its triphosphorylated form, increases the survival of yeast strains in ex vivo blood infections. Finally, we show the importance of the DNA damage response that activates dNTP biosynthesis in yeast cells during ex vivo blood infections. We conclude that opportunistic yeasts may use an enhanced de novo biosynthesis of the purine nucleotides pathway to increase survival and favor infections in the host.
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Affiliation(s)
| | - Silvia Llopis
- Instituto de Agroquímica y Tecnología de los Alimentos, CSIC, Valencia, Spain
| | - Benedetta Perrone
- Instituto de Agroquímica y Tecnología de los Alimentos, CSIC, Valencia, Spain
- Department of Agricultural, Forest and Food Sciences Microbiology and Food Technologies Unit University of Torino, Torino, Italy
| | - Rocío Gómez-Pastor
- Instituto de Agroquímica y Tecnología de los Alimentos, CSIC, Valencia, Spain
| | - Bernhard Hube
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology, Hans-Knoell-Institute (HKI), Jena, Germany
- Friedrich Schiller University, Jena, Germany
| | - Amparo Querol
- Instituto de Agroquímica y Tecnología de los Alimentos, CSIC, Valencia, Spain
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43
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Chitty JL, Fraser JA. Rethinking the targets for antifungal development. MICROBIOLOGY AUSTRALIA 2015. [DOI: 10.1071/ma15028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Desalermos A, Tan X, Rajamuthiah R, Arvanitis M, Wang Y, Li D, Kourkoumpetis TK, Fuchs BB, Mylonakis E. A multi-host approach for the systematic analysis of virulence factors in Cryptococcus neoformans. J Infect Dis 2014; 211:298-305. [PMID: 25114160 DOI: 10.1093/infdis/jiu441] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
A multi-host approach was followed to screen a library of 1201 signature-tagged deletion strains of Cryptococcus neoformans mutants to identify previously unknown virulence factors. The primary screen was performed using a Caenorhabditis elegans-C. neoformans infection assay. The hits among these strains were reconfirmed as less virulent than the wild type in the insect Galleria mellonella-C. neoformans infection assay. After this 2-stage screen, and to prioritize hits, we performed serial evaluations of the selected strains, using the C. elegans model. All hit strains identified through these studies were validated in a murine model of systemic cryptococcosis. Twelve strains were identified through a stepwise screening assay. Among them, 4 (CSN1201, SRE1, RDI1, and YLR243W) were previously discovered, providing proof of principle for this approach, while the role of the remaining 8 genes (CKS101, CNC5600, YOL003C, CND1850, MLH3, HAP502, MSL5, and CNA2580) were not previously described in cryptococcal virulence. The multi-host approach is an efficient method of studying the pathogenesis of C. neoformans. We used diverse model hosts, C. elegans, G. mellonella, and mice, with physiological differences and identified 12 genes associated with mammalian infection. Our approach may be suitable for large pathogenesis screens.
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Affiliation(s)
- Athanasios Desalermos
- Division of Infectious diseases, Warren Alpert Medical School of Brown University, Providence, Rhode Island
| | - Xiaojiang Tan
- Division of Infectious diseases, Warren Alpert Medical School of Brown University, Providence, Rhode Island
| | - Rajmohan Rajamuthiah
- Division of Infectious diseases, Warren Alpert Medical School of Brown University, Providence, Rhode Island
| | - Marios Arvanitis
- Division of Infectious diseases, Warren Alpert Medical School of Brown University, Providence, Rhode Island
| | - Yan Wang
- Division of Infectious diseases, Warren Alpert Medical School of Brown University, Providence, Rhode Island
| | - Dedong Li
- Division of Infectious diseases, Warren Alpert Medical School of Brown University, Providence, Rhode Island
| | | | - Beth Burgwyn Fuchs
- Division of Infectious diseases, Warren Alpert Medical School of Brown University, Providence, Rhode Island
| | - Eleftherios Mylonakis
- Division of Infectious diseases, Warren Alpert Medical School of Brown University, Providence, Rhode Island
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Coelho C, Bocca AL, Casadevall A. The tools for virulence of Cryptococcus neoformans. ADVANCES IN APPLIED MICROBIOLOGY 2014; 87:1-41. [PMID: 24581388 DOI: 10.1016/b978-0-12-800261-2.00001-3] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Cryptococcus neoformans is a fungal pathogen that causes almost half a million deaths each year. It is believed that most humans are infected with C. neoformans, possibly in a form that survives through latency in the lung and can reactivate to cause disease if the host becomes immunosuppressed. C. neoformans has a remarkably sophisticated intracellular survival capacities yet it is a free-living fungus with no requirement for mammalian virulence whatsoever. In this review, we discuss the tools that C. neoformans possesses to achieve survival, latency and virulence within its host. Some of these tools are mechanisms to withstand starvation and others aim to protect against microbicidal molecules produced by the immune system. Furthermore, we discuss how these tools were acquired through evolutionary pressures and perhaps accidental stochastic events, all of which combined to produce an organism with an unusual and unique intracellular pathogenic strategy.
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Affiliation(s)
- Carolina Coelho
- Department of Microbiology and Immunology, Albert Einstein College of Medicine of Yeshiva University, New York, USA; Centre for Neuroscience and Cell Biology of Coimbra, Institute of Microbiology, Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Anamelia Lorenzetti Bocca
- Department of Cellular Biology, Institute of Biological Sciences, University of Brasília, Brasília, Brazil
| | - Arturo Casadevall
- Department of Microbiology and Immunology, Albert Einstein College of Medicine of Yeshiva University, New York, USA.
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The role of the de novo pyrimidine biosynthetic pathway in Cryptococcus neoformans high temperature growth and virulence. Fungal Genet Biol 2014; 70:12-23. [PMID: 25011011 DOI: 10.1016/j.fgb.2014.06.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Revised: 06/09/2014] [Accepted: 06/14/2014] [Indexed: 11/21/2022]
Abstract
Fungal infections are often difficult to treat due to the inherent similarities between fungal and animal cells and the resulting host toxicity from many antifungal compounds. Cryptococcus neoformans is an opportunistic fungal pathogen of humans that causes life-threatening disease, primarily in immunocompromised patients. Since antifungal therapy for this microorganism is limited, many investigators have explored novel drug targets aim at virulence factors, such as the ability to grow at mammalian physiological temperature (37°C). To address this issue, we used the Agrobacterium tumefaciens gene delivery system to create a random insertion mutagenesis library that was screened for altered growth at elevated temperatures. Among several mutants unable to grow at 37°C, we explored one bearing an interruption in the URA4 gene. This gene encodes dihydroorotase (DHOase) that is involved in the de novo synthesis of pyrimidine ribonucleotides. Loss of the C. neoformans Ura4 protein, by targeted gene interruption, resulted in an expected uracil/uridine auxotrophy and an unexpected high temperature growth defect. In addition, the ura4 mutant displayed phenotypic defects in other prominent virulence factors (melanin, capsule and phospholipase) and reduced stress response compared to wild type and reconstituted strains. Accordingly, this mutant had a decreased survival rate in macrophages and attenuated virulence in a murine model of cryptococcal infection. Quantitative PCR analysis suggests that this biosynthetic pathway is induced during the transition from 30°C to 37°C, and that transcriptional regulation of de novo and salvage pyrimidine pathway are under the control of the Ura4 protein.
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Banerjee D, Burkard L, Panepinto JC. Inhibition of nucleotide biosynthesis potentiates the antifungal activity of amphotericin B. PLoS One 2014; 9:e87246. [PMID: 24498052 PMCID: PMC3907572 DOI: 10.1371/journal.pone.0087246] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 12/20/2013] [Indexed: 01/01/2023] Open
Abstract
The polyene antifungal agent Amphotericin B exhibits potent and broad spectrum fungicidal activity. However, high nephrotoxicity can hinder its administration in resource poor settings. Quantification of early fungicidal activity in studies of HIV patients with cryptococcosis demonstrate that 5-Fluorocytosine therapy in combination with Amphotericin B results in faster clearance than with Amphotericin B alone. In vitro synergy between the two drugs has also been reported but the mechanism by which 5-Fluorocytosine synergizes with Amphotericin B has not been delineated. In this study we set out to investigate the effect of genetic mutation or pharmacologic repression of de novo pyrimidine and purine biosynthesis pathways on the Amphotericin B susceptibility of Cryptococcus neoformans. We demonstrate that a ura- derivative of wild type Cryptococcus neoformans strain H99 is hypersensitive to Amphotericin B. This sensitivity is remediated by re-introduction of a wild type URA5 gene, but not by addition of exogenous uracil to supplement the auxotrophy. Repression of guanine biosynthesis by treatment with the inosine monophosphate dehydrogenase inhibitor, mycophenolic acid, was synergistic with Amphotericin B as determined by checkerboard analysis. As in Cryptococcus neoformans, a ura− derivative of Candida albicans was also hypersensitive to Amphotericin B, and treatment of Candida albicans with mycophenolic acid was likewise synergistic with Amphotericin B. In contrast, neither mycophenolic acid nor 5-FC had an effect on the Amphotericin B susceptibility of Aspergillus fumigatus. These studies suggest that pharmacological targeting of nucleotide biosynthesis pathways has potential to lower the effective dose of Amphotericin B for both C. neoformans and C. albicans. Given the requirement of nucleotide and nucleotide sugars for growth and pathogenesis of Cryptococcus neoformans, disrupting nucleotide metabolic pathways might thus be an effective mechanism for the development of novel antifungal drugs.
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Affiliation(s)
- Dithi Banerjee
- Department of Microbiology and Immunology, Witebsky Center for Microbial Pathogenesis and Immunology, University at Buffalo, The State University of New York, Buffalo, New York, United States of America
| | - Lauren Burkard
- Department of Microbiology and Immunology, Witebsky Center for Microbial Pathogenesis and Immunology, University at Buffalo, The State University of New York, Buffalo, New York, United States of America
| | - John C. Panepinto
- Department of Microbiology and Immunology, Witebsky Center for Microbial Pathogenesis and Immunology, University at Buffalo, The State University of New York, Buffalo, New York, United States of America
- * E-mail:
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48
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Identification of uric acid as the redox molecule secreted by the yeast Arxula adeninivorans. Appl Microbiol Biotechnol 2014; 98:2223-9. [DOI: 10.1007/s00253-013-5487-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 12/12/2013] [Accepted: 12/15/2013] [Indexed: 02/04/2023]
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49
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Blundell RD, Williams SJ, Morrow CA, Ericsson DJ, Kobe B, Fraser JA. Purification, crystallization and preliminary X-ray analysis of adenylosuccinate synthetase from the fungal pathogen Cryptococcus neoformans. Acta Crystallogr Sect F Struct Biol Cryst Commun 2013; 69:1033-6. [PMID: 23989157 PMCID: PMC3758157 DOI: 10.1107/s1744309113021921] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Accepted: 08/06/2013] [Indexed: 03/16/2023]
Abstract
With increasingly large immunocompromised populations around the world, opportunistic fungal pathogens such as Cryptococcus neoformans are a growing cause of morbidity and mortality. To combat the paucity of antifungal compounds, new drug targets must be investigated. Adenylosuccinate synthetase is a crucial enzyme in the ATP de novo biosynthetic pathway, catalyzing the formation of adenylosuccinate from inosine monophosphate and aspartate. Although the enzyme is ubiquitous and well characterized in other kingdoms, no crystallographic studies on the fungal protein have been performed. Presented here are the expression, purification, crystallization and initial crystallographic analyses of cryptococcal adenylosuccinate synthetase. The crystals had the symmetry of space group P2(1)2(1)2(1) and diffracted to 2.2 Å resolution.
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Affiliation(s)
- Ross D. Blundell
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Simon J. Williams
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Carl A. Morrow
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Daniel J. Ericsson
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Bostjan Kobe
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - James A. Fraser
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
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