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Anyaogu DC, Mortensen UH. Heterologous production of fungal secondary metabolites in Aspergilli. Front Microbiol 2015; 6:77. [PMID: 25713568 PMCID: PMC4322707 DOI: 10.3389/fmicb.2015.00077] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2014] [Accepted: 01/21/2015] [Indexed: 12/24/2022] Open
Abstract
Fungal natural products comprise a wide range of compounds. Some are medically attractive as drugs and drug leads, some are used as food additives, while others are harmful mycotoxins. In recent years the genome sequence of several fungi has become available providing genetic information of a large number of putative biosynthetic pathways. However, compound discovery is difficult as the genes required for the production of the compounds often are silent or barely expressed under laboratory conditions. Furthermore, the lack of available tools for genetic manipulation of most fungal species hinders pathway discovery. Heterologous expression of the biosynthetic pathway in model systems or cell factories facilitates product discovery, elucidation, and production. This review summarizes the recent strategies for heterologous expression of fungal biosynthetic pathways in Aspergilli.
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Affiliation(s)
- Diana Chinyere Anyaogu
- Section for Eukaryotic Biotechnology, Department of Systems Biology, Technical University of Denmark Kongens Lyngby, Denmark
| | - Uffe Hasbro Mortensen
- Section for Eukaryotic Biotechnology, Department of Systems Biology, Technical University of Denmark Kongens Lyngby, Denmark
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Rohlfs M. Fungal secondary metabolite dynamics in fungus-grazer interactions: novel insights and unanswered questions. Front Microbiol 2015; 5:788. [PMID: 25628619 PMCID: PMC4292314 DOI: 10.3389/fmicb.2014.00788] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 12/22/2014] [Indexed: 11/26/2022] Open
Abstract
In response to fungivore grazing fungi are assumed to have evolved secondary metabolite-based defense mechanisms that harm and repel grazers, and hence provide a benefit to the metabolite producer. However, since research into the ecological meaning of highly diverse fungal secondary metabolites is still in its infancy, many central questions still remain. Which components of the enormous metabolite diversity of fungi act as direct chemical defense mechanisms against grazers? Is the proposed chemical defense of fungi induced by grazer attack? Which role do volatile compounds play in communicating noxiousness to grazers? What is the relative impact of grazers and that of interactions with competing microbes on the evolution of fungal secondary metabolism? Here, I briefly summarize and discuss the results of the very few studies that have tried to tackle some of these questions by (i) using secondary metabolite mutant fungi in controlled experiments with grazers, and by (ii) investigating fungal secondary metabolism as a flexible means to adapt to grazer-rich niches.
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Affiliation(s)
- Marko Rohlfs
- Johann-Friedrich-Blumenbach Institute of Zoology and Anthropology, Georg-August-University Göttingen Göttingen, Germany
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53
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Frisvad JC. Taxonomy, chemodiversity, and chemoconsistency of Aspergillus, Penicillium, and Talaromyces species. Front Microbiol 2015; 5:773. [PMID: 25628613 PMCID: PMC4290622 DOI: 10.3389/fmicb.2014.00773] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2014] [Accepted: 12/17/2014] [Indexed: 11/17/2022] Open
Abstract
Aspergillus, Penicillium, and Talaromyces are among the most chemically inventive of all fungi, producing a wide array of secondary metabolites (exometabolites). The three genera are holophyletic in a cladistic sense and polythetic classes in an anagenetic or functional sense, and contain 344, 354, and 88 species, respectively. New developments in classification, cladification, and nomenclature have meant that the species, series, and sections suggested are natural groups that share many extrolites, including exometabolites, exoproteins, exocarbohydrates, and exolipids in addition to morphological features. The number of exometabolites reported from these species is very large, and genome sequencing projects have shown that a large number of additional exometabolites may be expressed, given the right conditions (“cryptic” gene clusters for exometabolites). The exometabolites are biosynthesized via shikimic acid, tricarboxylic acid cycle members, nucleotides, carbohydrates or as polyketides, non-ribosomal peptides, terpenes, or mixtures of those. The gene clusters coding for these compounds contain genes for the biosynthetic building blocks, the linking of these building blocks, tailoring enzymes, resistance for own products, and exporters. Species within a series or section in Aspergillus, Penicillium, and Talaromyces have many exometabolites in common, seemingly acquired by cladogenesis, but some the gene clusters for autapomorphic exometabolites may have been acquired by horizontal gene transfer. Despite genome sequencing efforts, and the many breakthroughs these will give, it is obvious that epigenetic factors play a large role in evolution and function of chemodiversity, and better methods for characterizing the epigenome are needed. Most of the individual species of the three genera produce a consistent and characteristic profile of exometabolites, but growth medium variations, stimulation by exometabolites from other species, and variations in abiotic intrinsic and extrinsic environmental factors such as pH, temperature, redox potential, and water activity will add significantly to the number of biosynthetic families expressed in anyone species. An example of the shared exometabolites in a natural group such as Aspergillus section Circumdati series Circumdati is that most, but not all species produce penicillic acids, aspyrones, neoaspergillic acids, xanthomegnins, melleins, aspergamides, circumdatins, and ochratoxins, in different combinations.
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Affiliation(s)
- Jens C Frisvad
- Section of Eukaryotic Biotechnology, Department of Systems Biology, Technical University of Denmark Kongens Lyngby, Denmark
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Fungal Secondary Metabolism in the Light of Animal–Fungus Interactions: From Mechanism to Ecological Function. Fungal Biol 2015. [DOI: 10.1007/978-1-4939-2531-5_9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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56
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Petersen AB, Rønnest MH, Larsen TO, Clausen MH. The Chemistry of Griseofulvin. Chem Rev 2014; 114:12088-107. [DOI: 10.1021/cr400368e] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Asger B. Petersen
- Center for Nanomedicine and Theranostics & Department of Chemistry, Technical University of Denmark, Kemitorvet 207, DK-2800 Kgs. Lyngby, Denmark
| | - Mads H. Rønnest
- Center for Nanomedicine and Theranostics & Department of Chemistry, Technical University of Denmark, Kemitorvet 207, DK-2800 Kgs. Lyngby, Denmark
| | - Thomas O. Larsen
- Department
of Systems Biology, Technical University of Denmark, Søltofts
Plads 221, DK-2800 Kgs. Lyngby, Denmark
| | - Mads H. Clausen
- Center for Nanomedicine and Theranostics & Department of Chemistry, Technical University of Denmark, Kemitorvet 207, DK-2800 Kgs. Lyngby, Denmark
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57
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Matsuda Y, Wakimoto T, Mori T, Awakawa T, Abe I. Complete Biosynthetic Pathway of Anditomin: Nature’s Sophisticated Synthetic Route to a Complex Fungal Meroterpenoid. J Am Chem Soc 2014; 136:15326-36. [DOI: 10.1021/ja508127q] [Citation(s) in RCA: 129] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Yudai Matsuda
- Graduate School of Pharmaceutical
Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Toshiyuki Wakimoto
- Graduate School of Pharmaceutical
Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Takahiro Mori
- Graduate School of Pharmaceutical
Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Takayoshi Awakawa
- Graduate School of Pharmaceutical
Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Ikuro Abe
- Graduate School of Pharmaceutical
Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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Samson R, Visagie C, Houbraken J, Hong SB, Hubka V, Klaassen C, Perrone G, Seifert K, Susca A, Tanney J, Varga J, Kocsubé S, Szigeti G, Yaguchi T, Frisvad J. Phylogeny, identification and nomenclature of the genus Aspergillus. Stud Mycol 2014; 78:141-73. [PMID: 25492982 PMCID: PMC4260807 DOI: 10.1016/j.simyco.2014.07.004] [Citation(s) in RCA: 640] [Impact Index Per Article: 64.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Aspergillus comprises a diverse group of species based on morphological, physiological and phylogenetic characters, which significantly impact biotechnology, food production, indoor environments and human health. Aspergillus was traditionally associated with nine teleomorph genera, but phylogenetic data suggest that together with genera such as Polypaecilum, Phialosimplex, Dichotomomyces and Cristaspora, Aspergillus forms a monophyletic clade closely related to Penicillium. Changes in the International Code of Nomenclature for algae, fungi and plants resulted in the move to one name per species, meaning that a decision had to be made whether to keep Aspergillus as one big genus or to split it into several smaller genera. The International Commission of Penicillium and Aspergillus decided to keep Aspergillus instead of using smaller genera. In this paper, we present the arguments for this decision. We introduce new combinations for accepted species presently lacking an Aspergillus name and provide an updated accepted species list for the genus, now containing 339 species. To add to the scientific value of the list, we include information about living ex-type culture collection numbers and GenBank accession numbers for available representative ITS, calmodulin, β-tubulin and RPB2 sequences. In addition, we recommend a standard working technique for Aspergillus and propose calmodulin as a secondary identification marker.
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Affiliation(s)
- R.A. Samson
- CBS-KNAW Fungal Biodiversity Centre, Uppsalalaan 8, NL-3584 CT Utrecht, The Netherlands
| | - C.M. Visagie
- CBS-KNAW Fungal Biodiversity Centre, Uppsalalaan 8, NL-3584 CT Utrecht, The Netherlands
| | - J. Houbraken
- CBS-KNAW Fungal Biodiversity Centre, Uppsalalaan 8, NL-3584 CT Utrecht, The Netherlands
| | - S.-B. Hong
- Korean Agricultural Culture Collection, National Academy of Agricultural Science, RDA, Suwon, South Korea
| | - V. Hubka
- Department of Botany, Charles University in Prague, Prague, Czech Republic
| | - C.H.W. Klaassen
- Medical Microbiology & Infectious Diseases, C70 Canisius Wilhelmina Hospital, 532 SZ Nijmegen, The Netherlands
| | - G. Perrone
- Institute of Sciences of Food Production National Research Council, 70126 Bari, Italy
| | - K.A. Seifert
- Biodiversity (Mycology), Eastern Cereal and Oilseed Research Centre, Agriculture & Agri-Food Canada, Ottawa, ON K1A 0C6, Canada
| | - A. Susca
- Institute of Sciences of Food Production National Research Council, 70126 Bari, Italy
| | - J.B. Tanney
- Biodiversity (Mycology), Eastern Cereal and Oilseed Research Centre, Agriculture & Agri-Food Canada, Ottawa, ON K1A 0C6, Canada
| | - J. Varga
- Department of Microbiology, Faculty of Science and Informatics, University of Szeged, H-6726 Szeged, Hungary
| | - S. Kocsubé
- Department of Microbiology, Faculty of Science and Informatics, University of Szeged, H-6726 Szeged, Hungary
| | - G. Szigeti
- Department of Microbiology, Faculty of Science and Informatics, University of Szeged, H-6726 Szeged, Hungary
| | - T. Yaguchi
- Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8673, Japan
| | - J.C. Frisvad
- Department of Systems Biology, Building 221, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
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Frisvad JC, Petersen LM, Lyhne EK, Larsen TO. Formation of sclerotia and production of indoloterpenes by Aspergillus niger and other species in section Nigri. PLoS One 2014; 9:e94857. [PMID: 24736731 PMCID: PMC3988082 DOI: 10.1371/journal.pone.0094857] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 03/19/2014] [Indexed: 01/04/2023] Open
Abstract
Several species in Aspergillus section Nigri have been reported to produce sclerotia on well-known growth media, such as Czapek yeast autolysate (CYA) agar, with sclerotia considered to be an important prerequisite for sexual development. However Aspergillus niger sensu stricto has not been reported to produce sclerotia, and is thought to be a purely asexual organism. Here we report, for the first time, the production of sclerotia by certain strains of Aspergillus niger when grown on CYA agar with raisins, or on other fruits or on rice. Up to 11 apolar indoloterpenes of the aflavinine type were detected by liquid chromatography and diode array and mass spectrometric detection where sclerotia were formed, including 10,23-dihydro-24,25-dehydroaflavinine. Sclerotium induction can thus be a way of inducing the production of new secondary metabolites from previously silent gene clusters. Cultivation of other species of the black aspergilli showed that raisins induced sclerotium formation by A. brasiliensis, A. floridensis A. ibericus, A. luchuensis, A. neoniger, A. trinidadensis and A. saccharolyticus for the first time.
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Affiliation(s)
- Jens C. Frisvad
- Chemodiversity Group, Department of Systems Biology, Technical University of Denmark, Lyngby, Denmark
- * E-mail:
| | - Lene M. Petersen
- Chemodiversity Group, Department of Systems Biology, Technical University of Denmark, Lyngby, Denmark
| | - E. Kirstine Lyhne
- Chemodiversity Group, Department of Systems Biology, Technical University of Denmark, Lyngby, Denmark
| | - Thomas O. Larsen
- Chemodiversity Group, Department of Systems Biology, Technical University of Denmark, Lyngby, Denmark
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Holm D, Petersen L, Klitgaard A, Knudsen P, Jarczynska Z, Nielsen K, Gotfredsen C, Larsen T, Mortensen U. Molecular and Chemical Characterization of the Biosynthesis of the 6-MSA-Derived Meroterpenoid Yanuthone D in Aspergillus niger. ACTA ACUST UNITED AC 2014; 21:519-529. [DOI: 10.1016/j.chembiol.2014.01.013] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Revised: 01/14/2014] [Accepted: 01/29/2014] [Indexed: 01/25/2023]
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Abstract
Oxidative rearrangements are key reactions during the biosyntheses of many secondary metabolites in fungi.
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Affiliation(s)
- Russell Cox
- Institute for Organic Chemistry
- Leibniz University of Hannover
- 30167 Hannover, Germany
- School of Chemistry
- University of Bristol
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63
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64
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Recent advances in genome mining of secondary metabolite biosynthetic gene clusters and the development of heterologous expression systems in Aspergillus nidulans. J Ind Microbiol Biotechnol 2013; 41:433-42. [PMID: 24342965 DOI: 10.1007/s10295-013-1386-z] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Accepted: 11/20/2013] [Indexed: 12/31/2022]
Abstract
Fungi are prolific producers of secondary metabolites (SMs) that show a variety of biological activities. Recent advances in genome sequencing have shown that fungal genomes harbor far more SM gene clusters than are expressed under conventional laboratory conditions. Activation of these "silent" gene clusters is a major challenge, and many approaches have been taken to attempt to activate them and, thus, unlock the vast treasure chest of fungal SMs. This review will cover recent advances in genome mining of SMs in Aspergillus nidulans. We will also discuss current updates in gene annotation of A. nidulans and recent developments in A. nidulans as a molecular genetic system, both of which are essential for rapid and efficient experimental verification of SM gene clusters on a genome-wide scale. Finally, we will describe advances in the use of A. nidulans as a heterologous expression system to aid in the analysis of SM gene clusters from other fungal species that do not have an established molecular genetic system.
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65
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Supercluster takes a walk on the wild side. Trends Microbiol 2013; 21:617-8. [PMID: 24239205 DOI: 10.1016/j.tim.2013.11.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 11/04/2013] [Indexed: 11/23/2022]
Abstract
In a recent Proc. Natl. Acad. Sci. USA paper by Wiemann et al., a gene supercluster for secondary metabolite production in Aspergillus fumigatus is genetically dissected. The analysis demonstrates that gene regulation takes place at different layers and that genes belonging to specific clusters are intertwined.
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66
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Deane CD, Mitchell DA. Lessons learned from the transformation of natural product discovery to a genome-driven endeavor. J Ind Microbiol Biotechnol 2013; 41:315-31. [PMID: 24142337 DOI: 10.1007/s10295-013-1361-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2013] [Accepted: 09/30/2013] [Indexed: 12/24/2022]
Abstract
Natural product discovery is currently undergoing a transformation from a phenotype-driven field to a genotype-driven one. The increasing availability of genome sequences, coupled with improved techniques for identifying biosynthetic gene clusters, has revealed that secondary metabolomes are strikingly vaster than previously thought. New approaches to correlate biosynthetic gene clusters with the compounds they produce have facilitated the production and isolation of a rapidly growing collection of what we refer to as "reverse-discovered" natural products, in analogy to reverse genetics. In this review, we present an extensive list of reverse-discovered natural products and discuss seven important lessons for natural product discovery by genome-guided methods: structure prediction, accurate annotation, continued study of model organisms, avoiding genome-size bias, genetic manipulation, heterologous expression, and potential engineering of natural product analogs.
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Affiliation(s)
- Caitlin D Deane
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
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Caballero Ortiz S, Trienens M, Rohlfs M. Induced fungal resistance to insect grazing: reciprocal fitness consequences and fungal gene expression in the Drosophila-Aspergillus model system. PLoS One 2013; 8:e74951. [PMID: 24023705 PMCID: PMC3758311 DOI: 10.1371/journal.pone.0074951] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Accepted: 08/07/2013] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Fungi are key dietary resources for many animals. Fungi, in consequence, have evolved sophisticated physical and chemical defences for repelling and impairing fungivores. Expression of such defences may entail costs, requiring diversion of energy and nutrients away from fungal growth and reproduction. Inducible resistance that is mounted after attack by fungivores may allow fungi to circumvent the potential costs of defence when not needed. However, no information exists on whether fungi display inducible resistance. We combined organism and fungal gene expression approaches to investigate whether fungivory induces resistance in fungi. METHODOLOGY/PRINCIPAL FINDINGS Here we show that grazing by larval fruit flies, Drosophila melanogaster, induces resistance in the filamentous mould, Aspergillus nidulans, to subsequent feeding by larvae of the same insect. Larval grazing triggered the expression of various putative fungal resistance genes, including the secondary metabolite master regulator gene laeA. Compared to the severe pathological effects of wild type A. nidulans, which led to 100% insect mortality, larval feeding on a laeA loss-of-function mutant resulted in normal insect development. Whereas the wild type fungus recovered from larval grazing, larvae eradicated the chemically deficient mutant. In contrast, mutualistic dietary yeast, Saccharomyces cerevisiae, reached higher population densities when exposed to Drosophila larval feeding. CONCLUSIONS/SIGNIFICANCE Our study presents novel evidence that insect grazing is capable of inducing resistance to further grazing in a filamentous fungus. This phenotypic shift in resistance to fungivory is accompanied by changes in the expression of genes involved in signal transduction, epigenetic regulation and secondary metabolite biosynthesis pathways. Depending on reciprocal insect-fungus fitness consequences, fungi may be selected for inducible resistance to maintain high fitness in fungivore-rich habitats. Induced fungal defence responses thus need to be included if we wish to have a complete conception of animal-fungus co-evolution, fungal gene regulation, and multitrophic interactions.
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Affiliation(s)
- Silvia Caballero Ortiz
- Johann-Friedrich-Blumenbach Institute for Zoology and Anthropology, Georg-August-University Göttingen, Göttingen, Germany
| | - Monika Trienens
- Johann-Friedrich-Blumenbach Institute for Zoology and Anthropology, Georg-August-University Göttingen, Göttingen, Germany
- Evolutionary Genetics, Centre for Ecological and Evolutionary Studies, University of Groningen, Groningen, The Netherlands
- Department of Animal Evolutionary Ecology, Institute for Evolution and Biodiversity, University of Münster, Münster, Germany
| | - Marko Rohlfs
- Johann-Friedrich-Blumenbach Institute for Zoology and Anthropology, Georg-August-University Göttingen, Göttingen, Germany
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Nielsen MT, Klejnstrup ML, Rohlfs M, Anyaogu DC, Nielsen JB, Gotfredsen CH, Andersen MR, Hansen BG, Mortensen UH, Larsen TO. Aspergillus nidulans synthesize insect juvenile hormones upon expression of a heterologous regulatory protein and in response to grazing by Drosophila melanogaster larvae. PLoS One 2013; 8:e73369. [PMID: 23991191 PMCID: PMC3753258 DOI: 10.1371/journal.pone.0073369] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2012] [Accepted: 07/29/2013] [Indexed: 11/30/2022] Open
Abstract
Secondary metabolites are known to serve a wide range of specialized functions including communication, developmental control and defense. Genome sequencing of several fungal model species revealed that the majority of predicted secondary metabolite related genes are silent in laboratory strains, indicating that fungal secondary metabolites remain an underexplored resource of bioactive molecules. In this study, we combine heterologous expression of regulatory proteins in Aspergillus nidulans with systematic variation of growth conditions and observe induced synthesis of insect juvenile hormone-III and methyl farnesoate. Both compounds are sesquiterpenes belonging to the juvenile hormone class. Juvenile hormones regulate developmental and metabolic processes in insects and crustaceans, but have not previously been reported as fungal metabolites. We found that feeding by Drosophila melanogaster larvae induced synthesis of juvenile hormone in A. nidulans indicating a possible role of juvenile hormone biosynthesis in affecting fungal-insect antagonisms.
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Affiliation(s)
| | | | - Marko Rohlfs
- J.F. Blumenbach Institute of Zoology and Anthropology, Georg-August-University Göttingen, Göttingen, Germany
| | | | | | | | | | - Bjarne Gram Hansen
- Department of Systems Biology, Technical University of Denmark, Kgs Lyngby, Denmark
| | - Uffe Hasbro Mortensen
- Department of Systems Biology, Technical University of Denmark, Kgs Lyngby, Denmark
- * E-mail: (UHM); (TOL)
| | - Thomas Ostenfeld Larsen
- Department of Systems Biology, Technical University of Denmark, Kgs Lyngby, Denmark
- * E-mail: (UHM); (TOL)
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69
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Matsuda Y, Awakawa T, Wakimoto T, Abe I. Spiro-Ring Formation is Catalyzed by a Multifunctional Dioxygenase in Austinol Biosynthesis. J Am Chem Soc 2013; 135:10962-5. [DOI: 10.1021/ja405518u] [Citation(s) in RCA: 102] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Yudai Matsuda
- Graduate School of Pharmaceutical
Sciences, The University of Tokyo, 7-3-1
Hongo, Bunkyo-ku, Tokyo
113-0033, Japan
| | - Takayoshi Awakawa
- Graduate School of Pharmaceutical
Sciences, The University of Tokyo, 7-3-1
Hongo, Bunkyo-ku, Tokyo
113-0033, Japan
| | - Toshiyuki Wakimoto
- Graduate School of Pharmaceutical
Sciences, The University of Tokyo, 7-3-1
Hongo, Bunkyo-ku, Tokyo
113-0033, Japan
| | - Ikuro Abe
- Graduate School of Pharmaceutical
Sciences, The University of Tokyo, 7-3-1
Hongo, Bunkyo-ku, Tokyo
113-0033, Japan
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Yaegashi J, Praseuth MB, Tyan SW, Sanchez JF, Entwistle R, Chiang YM, Oakley BR, Wang CCC. Molecular genetic characterization of the biosynthesis cluster of a prenylated isoindolinone alkaloid aspernidine A in Aspergillus nidulans. Org Lett 2013; 15:2862-5. [PMID: 23706169 DOI: 10.1021/ol401187b] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Aspernidine A is a prenylated isoindolinone alkaloid isolated from the model fungus Aspergillus nidulans. A genome-wide kinase knockout library of A. nidulans was examined, and it was found that a mitogen-activated protein kinase gene, mpkA, deletion strain produces aspernidine A. Targeted gene deletions were performed in the kinase deletion background to identify the gene cluster for aspernidine A biosynthesis. Intermediates were isolated from mutant strains which provided information about the aspernidine A biosynthesis pathway.
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Affiliation(s)
- Junko Yaegashi
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California 90089, USA
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Comprehensive annotation of secondary metabolite biosynthetic genes and gene clusters of Aspergillus nidulans, A. fumigatus, A. niger and A. oryzae. BMC Microbiol 2013; 13:91. [PMID: 23617571 PMCID: PMC3689640 DOI: 10.1186/1471-2180-13-91] [Citation(s) in RCA: 195] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Accepted: 04/15/2013] [Indexed: 11/24/2022] Open
Abstract
Background Secondary metabolite production, a hallmark of filamentous fungi, is an expanding area of research for the Aspergilli. These compounds are potent chemicals, ranging from deadly toxins to therapeutic antibiotics to potential anti-cancer drugs. The genome sequences for multiple Aspergilli have been determined, and provide a wealth of predictive information about secondary metabolite production. Sequence analysis and gene overexpression strategies have enabled the discovery of novel secondary metabolites and the genes involved in their biosynthesis. The Aspergillus Genome Database (AspGD) provides a central repository for gene annotation and protein information for Aspergillus species. These annotations include Gene Ontology (GO) terms, phenotype data, gene names and descriptions and they are crucial for interpreting both small- and large-scale data and for aiding in the design of new experiments that further Aspergillus research. Results We have manually curated Biological Process GO annotations for all genes in AspGD with recorded functions in secondary metabolite production, adding new GO terms that specifically describe each secondary metabolite. We then leveraged these new annotations to predict roles in secondary metabolism for genes lacking experimental characterization. As a starting point for manually annotating Aspergillus secondary metabolite gene clusters, we used antiSMASH (antibiotics and Secondary Metabolite Analysis SHell) and SMURF (Secondary Metabolite Unknown Regions Finder) algorithms to identify potential clusters in A. nidulans, A. fumigatus, A. niger and A. oryzae, which we subsequently refined through manual curation. Conclusions This set of 266 manually curated secondary metabolite gene clusters will facilitate the investigation of novel Aspergillus secondary metabolites.
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72
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Wasil Z, Pahirulzaman KAK, Butts C, Simpson TJ, Lazarus CM, Cox RJ. One pathway, many compounds: heterologous expression of a fungal biosynthetic pathway reveals its intrinsic potential for diversity. Chem Sci 2013. [DOI: 10.1039/c3sc51785c] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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73
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Transcriptional changes in the transition from vegetative cells to asexual development in the model fungus Aspergillus nidulans. EUKARYOTIC CELL 2012; 12:311-21. [PMID: 23264642 DOI: 10.1128/ec.00274-12] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Morphogenesis encompasses programmed changes in gene expression that lead to the development of specialized cell types. In the model fungus Aspergillus nidulans, asexual development involves the formation of characteristic cell types, collectively known as the conidiophore. With the aim of determining the transcriptional changes that occur upon induction of asexual development, we have applied massive mRNA sequencing to compare the expression pattern of 19-h-old submerged vegetative cells (hyphae) with that of similar hyphae after exposure to the air for 5 h. We found that the expression of 2,222 (20.3%) of the predicted 10,943 A. nidulans transcripts was significantly modified after air exposure, 2,035 being downregulated and 187 upregulated. The activation during this transition of genes that belong specifically to the asexual developmental pathway was confirmed. Another remarkable quantitative change occurred in the expression of genes involved in carbon or nitrogen primary metabolism. Genes participating in polar growth or sexual development were transcriptionally repressed, as were those belonging to the HogA/SakA stress response mitogen-activated protein (MAP) kinase pathway. We also identified significant expression changes in several genes purportedly involved in redox balance, transmembrane transport, secondary metabolite production, or transcriptional regulation, mainly binuclear-zinc cluster transcription factors. Genes coding for these four activities were usually grouped in metabolic clusters, which may bring regulatory implications for the induction of asexual development. These results provide a blueprint for further stage-specific gene expression studies during conidiophore development.
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74
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Accurate prediction of secondary metabolite gene clusters in filamentous fungi. Proc Natl Acad Sci U S A 2012; 110:E99-107. [PMID: 23248299 DOI: 10.1073/pnas.1205532110] [Citation(s) in RCA: 156] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Biosynthetic pathways of secondary metabolites from fungi are currently subject to an intense effort to elucidate the genetic basis for these compounds due to their large potential within pharmaceutics and synthetic biochemistry. The preferred method is methodical gene deletions to identify supporting enzymes for key synthases one cluster at a time. In this study, we design and apply a DNA expression array for Aspergillus nidulans in combination with legacy data to form a comprehensive gene expression compendium. We apply a guilt-by-association-based analysis to predict the extent of the biosynthetic clusters for the 58 synthases active in our set of experimental conditions. A comparison with legacy data shows the method to be accurate in 13 of 16 known clusters and nearly accurate for the remaining 3 clusters. Furthermore, we apply a data clustering approach, which identifies cross-chemistry between physically separate gene clusters (superclusters), and validate this both with legacy data and experimentally by prediction and verification of a supercluster consisting of the synthase AN1242 and the prenyltransferase AN11080, as well as identification of the product compound nidulanin A. We have used A. nidulans for our method development and validation due to the wealth of available biochemical data, but the method can be applied to any fungus with a sequenced and assembled genome, thus supporting further secondary metabolite pathway elucidation in the fungal kingdom.
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75
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Identification of a transcription factor controlling pH-dependent organic acid response in Aspergillus niger. PLoS One 2012; 7:e50596. [PMID: 23251373 PMCID: PMC3520943 DOI: 10.1371/journal.pone.0050596] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2012] [Accepted: 10/25/2012] [Indexed: 01/17/2023] Open
Abstract
Acid formation in Aspergillus niger is known to be subjected to tight regulation, and the acid production profiles are fine-tuned to respond to the ambient pH. Based on transcriptome data, putative trans-acting pH responding transcription factors were listed and through knock out studies, mutants exhibiting an oxalate overproducing phenotype were identified. The yield of oxalate was increased up to 158% compared to the wild type and the corresponding transcription factor was therefore entitled Oxalic Acid repression Factor, OafA. Detailed physiological characterization of one of the ΔoafA mutants, compared to the wild type, showed that both strains produced substantial amounts of gluconic acid, but the mutant strain was more efficient in re-uptake of gluconic acid and converting it to oxalic acid, particularly at high pH (pH 5.0). Transcriptional profiles showed that 241 genes were differentially expressed due to the deletion of oafA and this supported the argument of OafA being a trans-acting transcription factor. Furthermore, expression of two phosphoketolases was down-regulated in the ΔoafA mutant, one of which has not previously been described in fungi. It was argued that the observed oxalate overproducing phenotype was a consequence of the efficient re-uptake of gluconic acid and thereby a higher flux through glycolysis. This results in a lower flux through the pentose phosphate pathway, demonstrated by the down-regulation of the phosphoketolases. Finally, the physiological data, in terms of the specific oxygen consumption, indicated a connection between the oxidative phosphorylation and oxalate production and this was further substantiated through transcription analysis.
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76
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Pockrandt D, Ludwig L, Fan A, König GM, Li SM. New Insights into the Biosynthesis of Prenylated Xanthones: Xptb fromAspergillus nidulansCatalyses an O-Prenylation of Xanthones. Chembiochem 2012; 13:2764-71. [DOI: 10.1002/cbic.201200545] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Indexed: 12/18/2022]
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77
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de la Cruz M, Martín J, González-Menéndez V, Pérez-Victoria I, Moreno C, Tormo JR, El Aouad N, Guarro J, Vicente F, Reyes F, Bills GF. Chemical and physical modulation of antibiotic activity in emericella species. Chem Biodivers 2012; 9:1095-113. [PMID: 22700228 DOI: 10.1002/cbdv.201100362] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The addition of epigenetic modifying agents and ion-exchange resins to culture media and solid-state fermentations have been promoted as ways to stimulate expression of latent biosynthetic gene clusters and to modulate secondary metabolite biosynthesis. We asked how combination of these treatments would affect a population of screening isolates and their patterns of antibiosis relative to fermentation controls. A set of 43 Emericella strains, representing 25 species and varieties, were grown on a nutrient-rich medium comprising glucose, casein hydrolysate, urea, and mineral salts. Each strain was grown in untreated agitated liquid medium, a medium treated with suberoylanilide hydroxamic acid, a histone deacetylase inhibitor, 5-azacytidine, a DNA methylation inhibitor, an Amberlite non-ionic polyacrylate resin, and the same medium incorporated into an inert static vermiculite matrix. Species-inherent metabolic differences more strongly influenced patterns of antibiosis than medium treatments. The antibacterial siderophore, desferritriacetylfusigen, was detected in most species in liquid media, but not in the vermiculite medium. The predominant antifungal component detected was echinocandin B. Some species produced this antifungal regardless of treatment, although higher quantities were often produced in vermiculite. Several species are reported for the first time to produce echinocandin B. A new echinocandin analog, echinocandin E, was identified from E. quadrilineata.
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Affiliation(s)
- Mercedes de la Cruz
- Fundación MEDINA, Centro de Excelencia en Investigación de Medicamentos Innovadores en Andalucía, Avda. del Conocimiento 3, Parque Tecnológico de Ciencias de la Salud, ES-18100 Armilla, Granada
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78
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Breaking the silence: protein stabilization uncovers silenced biosynthetic gene clusters in the fungus Aspergillus nidulans. Appl Environ Microbiol 2012; 78:8234-44. [PMID: 23001671 DOI: 10.1128/aem.01808-12] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The genomes of filamentous fungi comprise numerous putative gene clusters coding for the biosynthesis of chemically and structurally diverse secondary metabolites (SMs), which are rarely expressed under laboratory conditions. Previous approaches to activate these genes were based primarily on artificially targeting the cellular protein synthesis apparatus. Here, we applied an alternative approach of genetically impairing the protein degradation apparatus of the model fungus Aspergillus nidulans by deleting the conserved eukaryotic csnE/CSN5 deneddylase subunit of the COP9 signalosome. This defect in protein degradation results in the activation of a previously silenced gene cluster comprising a polyketide synthase gene producing the antibiotic 2,4-dihydroxy-3-methyl-6-(2-oxopropyl)benzaldehyde (DHMBA). The csnE/CSN5 gene is highly conserved in fungi, and therefore, the deletion is a feasible approach for the identification of new SMs.
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79
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Schätzle MA, Husain SM, Ferlaino S, Müller M. Tautomers of Anthrahydroquinones: Enzymatic Reduction and Implications for Chrysophanol, Monodictyphenone, and Related Xanthone Biosyntheses. J Am Chem Soc 2012; 134:14742-5. [DOI: 10.1021/ja307151x] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Michael A. Schätzle
- Institut
für Pharmazeutische Wissenschaften, Albert-Ludwigs-Universität Freiburg, Albertstr.
25, 79104 Freiburg, Germany
| | - Syed Masood Husain
- Institut
für Pharmazeutische Wissenschaften, Albert-Ludwigs-Universität Freiburg, Albertstr.
25, 79104 Freiburg, Germany
| | - Sascha Ferlaino
- Institut
für Pharmazeutische Wissenschaften, Albert-Ludwigs-Universität Freiburg, Albertstr.
25, 79104 Freiburg, Germany
| | - Michael Müller
- Institut
für Pharmazeutische Wissenschaften, Albert-Ludwigs-Universität Freiburg, Albertstr.
25, 79104 Freiburg, Germany
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80
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Lin SH, Yoshimoto M, Lyu PC, Tang CY, Arita M. Phylogenomic and domain analysis of iterative polyketide synthases in Aspergillus species. Evol Bioinform Online 2012; 8:373-87. [PMID: 22844193 PMCID: PMC3399418 DOI: 10.4137/ebo.s9796] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Aspergillus species are industrially and agriculturally important as fermentors and as producers of various secondary metabolites. Among them, fungal polyketides such as lovastatin and melanin are considered a gold mine for bioactive compounds. We used a phylogenomic approach to investigate the distribution of iterative polyketide synthases (PKS) in eight sequenced Aspergilli and classified over 250 fungal genes. Their genealogy by the conserved ketosynthase (KS) domain revealed three large groups of nonreducing PKS, one group inside bacterial PKS, and more than 9 small groups of reducing PKS. Polyphyly of nonribosomal peptide synthase (NRPS)-PKS genes raised questions regarding the recruitment of the elegant conjugation machinery. High rates of gene duplication and divergence were frequent. All data are accessible through our web database at http://metabolomics.jp/wiki/Category:PK.
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Affiliation(s)
- Shu-Hsi Lin
- Institute of Bioinformatics and Structural Biology, National Tsing Hua University, Hsinchu, Taiwan
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81
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Sarkar A, Funk AN, Scherlach K, Horn F, Schroeckh V, Chankhamjon P, Westermann M, Roth M, Brakhage AA, Hertweck C, Horn U. Differential expression of silent polyketide biosynthesis gene clusters in chemostat cultures of Aspergillus nidulans. J Biotechnol 2012; 160:64-71. [DOI: 10.1016/j.jbiotec.2012.01.015] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2011] [Revised: 01/09/2012] [Accepted: 01/17/2012] [Indexed: 01/11/2023]
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82
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Simpson TJ. Genetic and biosynthetic studies of the fungal prenylated xanthone shamixanthone and related metabolites in Aspergillus spp. revisited. Chembiochem 2012; 13:1680-8. [PMID: 22730213 DOI: 10.1002/cbic.201200014] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2012] [Revised: 05/07/2012] [Indexed: 11/08/2022]
Abstract
Biosynthetic genes for the prenylated xanthone shamixanthone have been identified in the Aspergillus nidulans genome; based on assignment of putative functions from sequence analyses and selected gene deletions, a pathway was proposed leading from the anthraquinone emodin via the benzophenone carboxylic acid monodictyphenone and the xanthone emericellin to shamixanthone. Several aspects of this proposed pathway are inconsistent with previously identified biosynthetic intermediates: the anthraquinone chrysophanol and the benzophenone aldehyde derivatives arugosins F and A/B, isotopic labelling studies and chemical precedents. A new pathway is presented that provides a full rationale for the results of the gene deletion studies and reconciles them with previous biosynthetic results, and is in accord with established chemical and biosynthetic mechanisms. The importance of interpreting genetic information in terms of established biosynthetic events is discussed.
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Affiliation(s)
- Thomas J Simpson
- University of Bristol, School of Chemistry, Cantock's Close, Bristol, BS8 1TS, UK.
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83
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Ahuja M, Chiang YM, Chang SL, Praseuth MB, Entwistle R, Sanchez JF, Lo HC, Yeh HH, Oakley BR, Wang CCC. Illuminating the diversity of aromatic polyketide synthases in Aspergillus nidulans. J Am Chem Soc 2012; 134:8212-21. [PMID: 22510154 DOI: 10.1021/ja3016395] [Citation(s) in RCA: 133] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Genome sequencing has revealed that fungi have the ability to synthesize many more natural products (NPs) than are currently known, but methods for obtaining suitable expression of NPs have been inadequate. We have developed a successful strategy that bypasses normal regulatory mechanisms. By efficient gene targeting, we have replaced, en masse, the promoters of nonreducing polyketide synthase (NR-PKS) genes, key genes in NP biosynthetic pathways, and other genes necessary for NR-PKS product formation or release. This has allowed us to determine the products of eight NR-PKSs of Aspergillus nidulans, including seven novel compounds, as well as the NR-PKS genes required for the synthesis of the toxins alternariol (8) and cichorine (19).
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Affiliation(s)
- Manmeet Ahuja
- Department of Molecular Biosciences, University of Kansas, 1200 Sunnyside Avenue, Lawrence, Kansas 66045, United States
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84
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Identification of a Key Prenyltransferase Involved in Biosynthesis of the Most Abundant Fungal Meroterpenoids Derived from 3,5-Dimethylorsellinic Acid. Chembiochem 2012; 13:1132-5. [DOI: 10.1002/cbic.201200124] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Indexed: 11/07/2022]
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85
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Involvement of a natural fusion of a cytochrome P450 and a hydrolase in mycophenolic acid biosynthesis. Appl Environ Microbiol 2012; 78:4908-13. [PMID: 22544261 DOI: 10.1128/aem.07955-11] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Mycophenolic acid (MPA) is a fungal secondary metabolite and the active component in several immunosuppressive pharmaceuticals. The gene cluster coding for the MPA biosynthetic pathway has recently been discovered in Penicillium brevicompactum, demonstrating that the first step is catalyzed by MpaC, a polyketide synthase producing 5-methylorsellinic acid (5-MOA). However, the biochemical role of the enzymes encoded by the remaining genes in the MPA gene cluster is still unknown. Based on bioinformatic analysis of the MPA gene cluster, we hypothesized that the step following 5-MOA production in the pathway is carried out by a natural fusion enzyme MpaDE, consisting of a cytochrome P450 (MpaD) in the N-terminal region and a hydrolase (MpaE) in the C-terminal region. We verified that the fusion gene is indeed expressed in P. brevicompactum by obtaining full-length sequence of the mpaDE cDNA prepared from the extracted RNA. Heterologous coexpression of mpaC and the fusion gene mpaDE in the MPA-nonproducer Aspergillus nidulans resulted in the production of 5,7-dihydroxy-4-methylphthalide (DHMP), the second intermediate in MPA biosynthesis. Analysis of the strain coexpressing mpaC and the mpaD part of mpaDE shows that the P450 catalyzes hydroxylation of 5-MOA to 4,6-dihydroxy-2-(hydroxymethyl)-3-methylbenzoic acid (DHMB). DHMB is then converted to DHMP, and our results suggest that the hydrolase domain aids this second step by acting as a lactone synthase that catalyzes the ring closure. Overall, the chimeric enzyme MpaDE provides insight into the genetic organization of the MPA biosynthesis pathway.
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86
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Rodríguez-Urra AB, Jiménez C, Nieto MI, Rodríguez J, Hayashi H, Ugalde U. Signaling the induction of sporulation involves the interaction of two secondary metabolites in Aspergillus nidulans. ACS Chem Biol 2012; 7:599-606. [PMID: 22234162 DOI: 10.1021/cb200455u] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
When growing Aspergillus nidulans hyphae encounter the atmosphere, they initiate a morphogenetic program leading to the production of spores. Mutants that are defective in the fluG gene fail to undergo sporulation because they lack an endogenous diffusible factor that purportedly accumulates on aerial hyphae, thus signaling the initiation of development. In this study, the defect could be reversed by adding culture extracts from a wild-type strain onto a mutant colony. Moreover, a bioassay-guided purification of the active culture extract resulted in the identification of the active agent as dehydroaustinol. However, this meroterpenoid was active only when administered in conjunction with the orsellinic acid derivative diorcinol. These two compounds formed an adduct that was detected by HRMS in an LC-MS experiment. The diorcinol-dehydroaustinol adduct prevented crystal formation of the signal on the surface of aerial hyphae and on an artificially prepared aqueous film and also increased the signal lipophilicity.
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Affiliation(s)
- Ana Belén Rodríguez-Urra
- Department
of Applied Chemistry,
Faculty of Chemistry, University of The Basque Country, San Sebastian 20018, Spain
| | - Carlos Jiménez
- Departament of Fundamental Chemistry,
Faculty of Sciences Campus da Zapateira, University of A Coruña, 15071 A Coruña, Spain
| | - María Isabel Nieto
- Departament of Fundamental Chemistry,
Faculty of Sciences Campus da Zapateira, University of A Coruña, 15071 A Coruña, Spain
| | - Jaime Rodríguez
- Departament of Fundamental Chemistry,
Faculty of Sciences Campus da Zapateira, University of A Coruña, 15071 A Coruña, Spain
| | - Hideo Hayashi
- Graduate School of Life and Environmental
Sciences, Osaka Prefecture University,
1-1 Gakuen-chou, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Unai Ugalde
- Department
of Applied Chemistry,
Faculty of Chemistry, University of The Basque Country, San Sebastian 20018, Spain
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87
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Lo HC, Entwistle R, Guo CJ, Ahuja M, Szewczyk E, Hung JH, Chiang YM, Oakley BR, Wang CCC. Two separate gene clusters encode the biosynthetic pathway for the meroterpenoids austinol and dehydroaustinol in Aspergillus nidulans. J Am Chem Soc 2012; 134:4709-20. [PMID: 22329759 DOI: 10.1021/ja209809t] [Citation(s) in RCA: 196] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Meroterpenoids are a class of fungal natural products that are produced from polyketide and terpenoid precursors. An understanding of meroterpenoid biosynthesis at the genetic level should facilitate engineering of second-generation molecules and increasing production of first-generation compounds. The filamentous fungus Aspergillus nidulans has previously been found to produce two meroterpenoids, austinol and dehydroaustinol. Using targeted deletions that we created, we have determined that, surprisingly, two separate gene clusters are required for meroterpenoid biosynthesis. One is a cluster of four genes including a polyketide synthase gene, ausA. The second is a cluster of 10 additional genes including a prenyltransferase gene, ausN, located on a separate chromosome. Chemical analysis of mutant extracts enabled us to isolate 3,5-dimethylorsellinic acid and 10 additional meroterpenoids that are either intermediates or shunt products from the biosynthetic pathway. Six of them were identified as novel meroterpenoids in this study. Our data, in aggregate, allow us to propose a complete biosynthetic pathway for the A. nidulans meroterpenoids.
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Affiliation(s)
- Hsien-Chun Lo
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, California 90089, United States
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88
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Dalsgaard PW, Petersen BO, Duus JØ, Zidorn C, Frisvad JC, Christophersen C, Larsen TO. Atlantinone A, a Meroterpenoid Produced by Penicillium ribeum and Several Cheese Associated Penicillium Species. Metabolites 2012; 2:214-20. [PMID: 24957375 PMCID: PMC3901203 DOI: 10.3390/metabo2010214] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Revised: 12/30/2011] [Accepted: 02/10/2012] [Indexed: 01/03/2023] Open
Abstract
Atlantinone A has been isolated from the psychrotolerant fungus Penicillium ribeum. The exact structure of the compound was confirmed by mass spectrometric and 1- and 2D NMR experiments. Atlantinone A was originally only produced upon chemical epigenetic manipulation of P. hirayamae, however in this study the compound was found to be produced at standard growth conditions by the following species; P. solitum, P. discolor, P. commune, P. caseifulvum, P. palitans, P. novae-zeelandiae and P. monticola. A biosynthetic pathway to atlantinone A starting from andrastin A is proposed.
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Affiliation(s)
- Petur W Dalsgaard
- Department of Forensic Medicine, University of Copenhagen, Frederik V's Vej 11, DK-2100 Copenhagen, Denmark
| | - Bent O Petersen
- Carlsberg Laboratory, Gamle Carlsbergvej 10, DK-2500 Valby, Denmark
| | | | - Christian Zidorn
- Institut für Pharmazie, Leopold-Franzens-Universität, Innrain 52, A-6020 Innsbruck, Austria
| | - Jens C Frisvad
- Center for Microbial Biotechnology, DTU Systems Biology, Building 221, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Carsten Christophersen
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
| | - Thomas O Larsen
- Center for Microbial Biotechnology, DTU Systems Biology, Building 221, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark.
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89
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Klejnstrup ML, Frandsen RJN, Holm DK, Nielsen MT, Mortensen UH, Larsen TO, Nielsen JB. Genetics of Polyketide Metabolism in Aspergillus nidulans. Metabolites 2012; 2:100-33. [PMID: 24957370 PMCID: PMC3901194 DOI: 10.3390/metabo2010100] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Revised: 12/23/2011] [Accepted: 01/17/2012] [Indexed: 12/12/2022] Open
Abstract
Secondary metabolites are small molecules that show large structural diversity and a broad range of bioactivities. Some metabolites are attractive as drugs or pigments while others act as harmful mycotoxins. Filamentous fungi have the capacity to produce a wide array of secondary metabolites including polyketides. The majority of genes required for production of these metabolites are mostly organized in gene clusters, which often are silent or barely expressed under laboratory conditions, making discovery and analysis difficult. Fortunately, the genome sequences of several filamentous fungi are publicly available, greatly facilitating the establishment of links between genes and metabolites. This review covers the attempts being made to trigger the activation of polyketide metabolism in the fungal model organism Aspergillus nidulans. Moreover, it will provide an overview of the pathways where ten polyketide synthase genes have been coupled to polyketide products. Therefore, the proposed biosynthesis of the following metabolites will be presented; naphthopyrone, sterigmatocystin, aspyridones, emericellamides, asperthecin, asperfuranone, monodictyphenone/emodin, orsellinic acid, and the austinols.
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Affiliation(s)
- Marie L Klejnstrup
- Department of Systems Biology, Center for Microbial Biotechnology, Technical University of Denmark, Søltofts Plads B221, DK-2800 Kgs. Lyngby, Denmark.
| | - Rasmus J N Frandsen
- Department of Systems Biology, Center for Microbial Biotechnology, Technical University of Denmark, Søltofts Plads B223, DK-2800 Kgs. Lyngby, Denmark.
| | - Dorte K Holm
- Department of Systems Biology, Center for Microbial Biotechnology, Technical University of Denmark, Søltofts Plads B223, DK-2800 Kgs. Lyngby, Denmark.
| | - Morten T Nielsen
- Department of Systems Biology, Center for Microbial Biotechnology, Technical University of Denmark, Søltofts Plads B223, DK-2800 Kgs. Lyngby, Denmark.
| | - Uffe H Mortensen
- Department of Systems Biology, Center for Microbial Biotechnology, Technical University of Denmark, Søltofts Plads B223, DK-2800 Kgs. Lyngby, Denmark.
| | - Thomas O Larsen
- Department of Systems Biology, Center for Microbial Biotechnology, Technical University of Denmark, Søltofts Plads B221, DK-2800 Kgs. Lyngby, Denmark.
| | - Jakob B Nielsen
- Department of Systems Biology, Center for Microbial Biotechnology, Technical University of Denmark, Søltofts Plads B223, DK-2800 Kgs. Lyngby, Denmark.
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90
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Sanchez JF, Somoza AD, Keller NP, Wang CCC. Advances in Aspergillus secondary metabolite research in the post-genomic era. Nat Prod Rep 2012; 29:351-71. [PMID: 22228366 DOI: 10.1039/c2np00084a] [Citation(s) in RCA: 194] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
This review studies the impact of whole genome sequencing on Aspergillus secondary metabolite research. There has been a proliferation of many new, intriguing discoveries since sequencing data became widely available. What is more, the genomes disclosed the surprising finding that there are many more secondary metabolite biosynthetic pathways than laboratory research had suggested. Activating these pathways has been met with some success, but many more dormant genes remain to be awakened.
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Affiliation(s)
- James F Sanchez
- University of Southern California-Pharmacology and Pharmaceutical Sciences, Los Angeles, California 90033, USA
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91
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Butts CP, Jones CR, Song Z, Simpson TJ. Accurate NOE-distance determination enables the stereochemical assignment of a flexible molecule – arugosin C. Chem Commun (Camb) 2012; 48:9023-5. [DOI: 10.1039/c2cc32144k] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Frisvad JC. Media and growth conditions for induction of secondary metabolite production. Methods Mol Biol 2012; 944:47-58. [PMID: 23065607 DOI: 10.1007/978-1-62703-122-6_3] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Growth media and incubation conditions have a very strong influence of secondary metabolite production. There is no consensus on which media are the optimal for metabolite production, but a series of useful and effective media and incubation conditions have been listed here. Chemically well-defined media are suited for biochemical studies, but in order to get chemical diversity expressed in filamentous fungi, sources rich in amino acids, vitamins, and trace metals have to be added, such as yeast extract and oatmeal. A battery of solid agar media is recommended for exploration of chemical diversity as agar plug samples are easily analyzed to get an optimal representation of the qualitative secondary metabolome. Standard incubation for a week at 25°C in darkness is recommended, but optimal conditions have to be modified depending on the ecology and physiology of different filamentous fungi.
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Affiliation(s)
- Jens C Frisvad
- Department of Systems Biology, Center for Microbial Biotechnology, Technical University of Denmark, Kongens Lyngby, Denmark.
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