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Cephalosporins as key lead generation beta-lactam antibiotics. Appl Microbiol Biotechnol 2022; 106:8007-8020. [DOI: 10.1007/s00253-022-12272-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Abstract
Antibiotics are antibacterial compounds that interfere with bacterial growth, without harming the infected eukaryotic host. Among the clinical agents, beta-lactams play a major role in treating infected humans and animals. However, the ever-increasing antibiotic resistance crisis is forcing the pharmaceutical industry to search for new antibacterial drugs to combat a range of current and potential multi-resistant bacterial pathogens. In this review, we provide an overview of the development, innovation, and current status of therapeutic applications for beta-lactams with a focus on semi-synthetic cephalosporins. Cephalosporin C (CPC), which is a natural secondary metabolite from the filamentous fungus Acremonium chrysogenum, plays a major and demanding role in both producing modern antibiotics and developing new ones. CPC serves as a core compound for producing semi-synthetic cephalosporins that can control infections with different resistance mechanisms. We therefore summarize our latest knowledge about the CPC biosynthetic pathway and its regulation in the fungal host. Finally, we describe how CPC serves as a key lead generation source for the in vitro and better, in vivo synthesis of 7-aminocephalosporanic acid (7-ACA), the major core compound for the pharmaceutical synthesis of current and future semi-synthetic cephalosporins.
Key points
•Latest literature on cephalosporin generations
•Biotechnical production of cephalosporins
•In vivo production of 7-ACA
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2
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Fierro F, Vaca I, Castillo NI, García-Rico RO, Chávez R. Penicillium chrysogenum, a Vintage Model with a Cutting-Edge Profile in Biotechnology. Microorganisms 2022; 10:microorganisms10030573. [PMID: 35336148 PMCID: PMC8954384 DOI: 10.3390/microorganisms10030573] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 02/15/2022] [Accepted: 02/17/2022] [Indexed: 12/20/2022] Open
Abstract
The discovery of penicillin entailed a decisive breakthrough in medicine. No other medical advance has ever had the same impact in the clinical practise. The fungus Penicillium chrysogenum (reclassified as P. rubens) has been used for industrial production of penicillin ever since the forties of the past century; industrial biotechnology developed hand in hand with it, and currently P. chrysogenum is a thoroughly studied model for secondary metabolite production and regulation. In addition to its role as penicillin producer, recent synthetic biology advances have put P. chrysogenum on the path to become a cell factory for the production of metabolites with biotechnological interest. In this review, we tell the history of P. chrysogenum, from the discovery of penicillin and the first isolation of strains with high production capacity to the most recent research advances with the fungus. We will describe how classical strain improvement programs achieved the goal of increasing production and how the development of different molecular tools allowed further improvements. The discovery of the penicillin gene cluster, the origin of the penicillin genes, the regulation of penicillin production, and a compilation of other P. chrysogenum secondary metabolites will also be covered and updated in this work.
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Affiliation(s)
- Francisco Fierro
- Departamento de Biotecnología, Universidad Autónoma Metropolitana-Unidad Iztapalapa, Ciudad de México 09340, Mexico
- Correspondence:
| | - Inmaculada Vaca
- Departamento de Química, Facultad de Ciencias, Universidad de Chile, Santiago 7800003, Chile;
| | - Nancy I. Castillo
- Grupo de Investigación en Ciencias Biológicas y Químicas, Facultad de Ciencias, Universidad Antonio Nariño, Bogotá 110231, Colombia;
| | - Ramón Ovidio García-Rico
- Grupo de Investigación GIMBIO, Departamento De Microbiología, Facultad de Ciencias Básicas, Universidad de Pamplona, Pamplona 543050, Colombia;
| | - Renato Chávez
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago 9170020, Chile;
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Jimdjio CK, Xue H, Bi Y, Nan M, Li L, Zhang R, Liu Q, Pu L. Effect of Ambient pH on Growth, Pathogenicity, and Patulin Production of Penicillium expansum. Toxins (Basel) 2021; 13:550. [PMID: 34437421 PMCID: PMC8402621 DOI: 10.3390/toxins13080550] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 08/04/2021] [Accepted: 08/05/2021] [Indexed: 11/17/2022] Open
Abstract
Penicillium expansum is an important postharvest pathogen of pomaceous fruit and a causal agent of blue mold or soft rot. In this study, we investigated the effect of ambient pH on growth, ultrastructure alteration, and pathogenicity of P. expansum, as well as accumulation of patulin and expression of genes involved in patulin biosynthesis. Under different pH, the fungus was routinely cultured and collected for growth, pathogenicity, patulin production, and gene expression studies using transmission electron microscopy, apple inoculation, HPLC, and RT-qPCR methods. Different ambient pH had significant impact on expression of genes and growth factors involved in patulin biosynthesis. Under same range of pH, gene expression profile, growth factors, and patulin accumulation (in vivo and in vitro) all showed similar changing trends. A well-developed cell was observed in addition to upregulation of genes at pH between pH 5.0 and 7.0, while the opposite was observed when pH was too basic (8.5) or too acid (2.5). Additionally, ambient pH had direct or indirect influence on expression of PecreaA, PelaeA, and PepacC. These findings will help in understanding the effect of ambient pH on growth, pathogenicity, and patulin production and support the development of successful methods for combating P. expansum infection on apple fruits.
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Affiliation(s)
- Carelle Kouasseu Jimdjio
- College of Science, Gansu Agricultural University, Lanzhou 730070, China; (C.K.J.); (M.N.); (L.L.); (Q.L.); (L.P.)
| | - Huali Xue
- College of Science, Gansu Agricultural University, Lanzhou 730070, China; (C.K.J.); (M.N.); (L.L.); (Q.L.); (L.P.)
| | - Yang Bi
- College of Food Science and Engineering, Gansu Agricultural University, Lanzhou 730070, China;
| | - Mina Nan
- College of Science, Gansu Agricultural University, Lanzhou 730070, China; (C.K.J.); (M.N.); (L.L.); (Q.L.); (L.P.)
| | - Lan Li
- College of Science, Gansu Agricultural University, Lanzhou 730070, China; (C.K.J.); (M.N.); (L.L.); (Q.L.); (L.P.)
| | - Rui Zhang
- College of Food Science and Engineering, Gansu Agricultural University, Lanzhou 730070, China;
| | - Qili Liu
- College of Science, Gansu Agricultural University, Lanzhou 730070, China; (C.K.J.); (M.N.); (L.L.); (Q.L.); (L.P.)
| | - Lumei Pu
- College of Science, Gansu Agricultural University, Lanzhou 730070, China; (C.K.J.); (M.N.); (L.L.); (Q.L.); (L.P.)
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4
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El Hajj Assaf C, Zetina-Serrano C, Tahtah N, Khoury AE, Atoui A, Oswald IP, Puel O, Lorber S. Regulation of Secondary Metabolism in the Penicillium Genus. Int J Mol Sci 2020; 21:E9462. [PMID: 33322713 PMCID: PMC7763326 DOI: 10.3390/ijms21249462] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 12/03/2020] [Accepted: 12/08/2020] [Indexed: 12/13/2022] Open
Abstract
Penicillium, one of the most common fungi occurring in a diverse range of habitats, has a worldwide distribution and a large economic impact on human health. Hundreds of the species belonging to this genus cause disastrous decay in food crops and are able to produce a varied range of secondary metabolites, from which we can distinguish harmful mycotoxins. Some Penicillium species are considered to be important producers of patulin and ochratoxin A, two well-known mycotoxins. The production of these mycotoxins and other secondary metabolites is controlled and regulated by different mechanisms. The aim of this review is to highlight the different levels of regulation of secondary metabolites in the Penicillium genus.
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Affiliation(s)
- Christelle El Hajj Assaf
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRAE, ENVT, INP-Purpan, UPS, 31027 Toulouse, France; (C.E.H.A.); (C.Z.-S.); (N.T.); (I.P.O.); (S.L.)
- Institute for Agricultural and Fisheries Research (ILVO), member of Food2Know, Brusselsesteenweg 370, 9090 Melle, Belgium
| | - Chrystian Zetina-Serrano
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRAE, ENVT, INP-Purpan, UPS, 31027 Toulouse, France; (C.E.H.A.); (C.Z.-S.); (N.T.); (I.P.O.); (S.L.)
| | - Nadia Tahtah
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRAE, ENVT, INP-Purpan, UPS, 31027 Toulouse, France; (C.E.H.A.); (C.Z.-S.); (N.T.); (I.P.O.); (S.L.)
- Centre D’analyse et de Recherche, Unité de Recherche Technologies et Valorisations Agro-Alimentaires, Faculté des Sciences, Université Saint-Joseph, P.O. Box 17-5208, Mar Mikhael, Beirut 1104, Lebanon;
| | - André El Khoury
- Centre D’analyse et de Recherche, Unité de Recherche Technologies et Valorisations Agro-Alimentaires, Faculté des Sciences, Université Saint-Joseph, P.O. Box 17-5208, Mar Mikhael, Beirut 1104, Lebanon;
| | - Ali Atoui
- Laboratory of Microbiology, Department of Life and Earth Sciences, Faculty of Sciences I, Lebanese University, Hadath Campus, P.O. Box 5, Beirut 1104, Lebanon;
| | - Isabelle P. Oswald
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRAE, ENVT, INP-Purpan, UPS, 31027 Toulouse, France; (C.E.H.A.); (C.Z.-S.); (N.T.); (I.P.O.); (S.L.)
| | - Olivier Puel
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRAE, ENVT, INP-Purpan, UPS, 31027 Toulouse, France; (C.E.H.A.); (C.Z.-S.); (N.T.); (I.P.O.); (S.L.)
| | - Sophie Lorber
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRAE, ENVT, INP-Purpan, UPS, 31027 Toulouse, France; (C.E.H.A.); (C.Z.-S.); (N.T.); (I.P.O.); (S.L.)
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Pathak A, Nowell RW, Wilson CG, Ryan MJ, Barraclough TG. Comparative genomics of Alexander Fleming's original Penicillium isolate (IMI 15378) reveals sequence divergence of penicillin synthesis genes. Sci Rep 2020; 10:15705. [PMID: 32973216 PMCID: PMC7515868 DOI: 10.1038/s41598-020-72584-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 09/03/2020] [Indexed: 11/18/2022] Open
Abstract
Antibiotics were derived originally from wild organisms and therefore understanding how these compounds evolve among different lineages might help with the design of new antimicrobial drugs. We report the draft genome sequence of Alexander Fleming’s original fungal isolate behind the discovery of penicillin, now classified as Penicillium rubens Biourge (1923) (IMI 15378). We compare the structure of the genome and genes involved in penicillin synthesis with those in two ‘high producing’ industrial strains of P. rubens and the closely related species P. nalgiovense. The main effector genes for producing penicillin G (pcbAB, pcbC and penDE) show amino acid divergence between the Fleming strain and both industrial strains, whereas a suite of regulatory genes are conserved. Homologs of penicillin N effector genes cefD1 and cefD2 were also found and the latter displayed amino acid divergence between the Fleming strain and industrial strains. The draft assemblies contain several partial duplications of penicillin-pathway genes in all three P. rubens strains, to differing degrees, which we hypothesise might be involved in regulation of the pathway. The two industrial strains are identical in sequence across all effector and regulatory genes but differ in duplication of the pcbAB–pcbC–penDE complex and partial duplication of fragments of regulatory genes. We conclude that evolution in the wild encompassed both sequence changes of the effector genes and gene duplication, whereas human-mediated changes through mutagenesis and artificial selection led to duplication of the penicillin pathway genes.
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Affiliation(s)
- Ayush Pathak
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Ascot, Berkshire, SL5 7PY, UK
| | - Reuben W Nowell
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Ascot, Berkshire, SL5 7PY, UK.,Department of Zoology, University of Oxford, 11a Mansfield Rd, Oxford, OX1 3SZ, UK
| | - Christopher G Wilson
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Ascot, Berkshire, SL5 7PY, UK.,Department of Zoology, University of Oxford, 11a Mansfield Rd, Oxford, OX1 3SZ, UK
| | | | - Timothy G Barraclough
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Ascot, Berkshire, SL5 7PY, UK. .,Department of Zoology, University of Oxford, 11a Mansfield Rd, Oxford, OX1 3SZ, UK.
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6
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García-Estrada C, Martín JF, Cueto L, Barreiro C. Omics Approaches Applied to Penicillium chrysogenum and Penicillin Production: Revealing the Secrets of Improved Productivity. Genes (Basel) 2020; 11:genes11060712. [PMID: 32604893 PMCID: PMC7348727 DOI: 10.3390/genes11060712] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 06/07/2020] [Accepted: 06/24/2020] [Indexed: 12/20/2022] Open
Abstract
Penicillin biosynthesis by Penicillium chrysogenum is one of the best-characterized biological processes from the genetic, molecular, biochemical, and subcellular points of view. Several omics studies have been carried out in this filamentous fungus during the last decade, which have contributed to gathering a deep knowledge about the molecular mechanisms underlying improved productivity in industrial strains. The information provided by these studies is extremely useful for enhancing the production of penicillin or other bioactive secondary metabolites by means of Biotechnology or Synthetic Biology.
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Affiliation(s)
- Carlos García-Estrada
- INBIOTEC (Instituto de Biotecnología de León). Avda. Real 1—Parque Científico de León, 24006 León, Spain; (L.C.); (C.B.)
- Departamento de Ciencias Biomédicas, Universidad de León, Campus de Vegazana s/n, 24071 León, Spain
- Correspondence: or ; Tel.: +34-987210308
| | - Juan F. Martín
- Área de Microbiología, Departamento de Biología Molecular, Facultad de Ciencias Biológicas y Ambientales, Universidad de León, 24071 León, Spain;
| | - Laura Cueto
- INBIOTEC (Instituto de Biotecnología de León). Avda. Real 1—Parque Científico de León, 24006 León, Spain; (L.C.); (C.B.)
| | - Carlos Barreiro
- INBIOTEC (Instituto de Biotecnología de León). Avda. Real 1—Parque Científico de León, 24006 León, Spain; (L.C.); (C.B.)
- Departamento de Biología Molecular, Universidad de León, Campus de Ponferrada, Avda. Astorga s/n, 24401 Ponferrada, Spain
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7
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Barda O, Maor U, Sadhasivam S, Bi Y, Zakin V, Prusky D, Sionov E. The pH-Responsive Transcription Factor PacC Governs Pathogenicity and Ochratoxin A Biosynthesis in Aspergillus carbonarius. Front Microbiol 2020; 11:210. [PMID: 32117191 PMCID: PMC7031272 DOI: 10.3389/fmicb.2020.00210] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 01/29/2020] [Indexed: 01/09/2023] Open
Abstract
Pathogenic fungi must respond effectively to changes in environmental pH for successful host colonization, virulence and toxin production. Aspergillus carbonarius is a mycotoxigenic pathogen with the ability to colonize many plant hosts and secrete ochratoxin A (OTA). In this study, we characterized the functions and addressed the role of PacC-mediated pH signaling in A. carbonarius pathogenicity using designed pacC gene knockout mutant. ΔAcpacC mutant displayed an acidity-mimicking phenotype, which resulted in impaired fungal growth at neutral/alkaline pH, accompanied by reduced sporulation and conidial germination compared to the wild type (WT) strain. The ΔAcpacC mutant was unable to efficiently acidify the growth media as a direct result of diminished gluconic and citric acid production. Furthermore, loss of AcpacC resulted in a complete inhibition of OTA production at pH 7.0. Additionally, ΔAcpacC mutant exhibited attenuated virulence compared to the WT toward grapes and nectarine fruits. Reintroduction of pacC gene into ΔAcpacC mutant restored the WT phenotype. Our results demonstrate important roles of PacC of A. carbonarius in OTA biosynthesis and in pathogenicity by controlling transcription of genes important for fungal secondary metabolism and infection.
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Affiliation(s)
- Omer Barda
- Institute of Postharvest and Food Sciences, Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel
| | - Uriel Maor
- Institute of Postharvest and Food Sciences, Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel.,Institute of Biochemistry, Food Science and Nutrition, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Sudharsan Sadhasivam
- Institute of Postharvest and Food Sciences, Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel
| | - Yang Bi
- College of Food Science and Engineering, Gansu Agricultural University, Lanzhou, China
| | - Varda Zakin
- Institute of Postharvest and Food Sciences, Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel
| | - Dov Prusky
- Institute of Postharvest and Food Sciences, Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel
| | - Edward Sionov
- Institute of Postharvest and Food Sciences, Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel
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Reus E, Nielsen MR, Frandsen RJN. Metabolic and regulatory insights from the experimental horizontal gene transfer of the aurofusarin and bikaverin gene clusters to
Aspergillus nidulans. Mol Microbiol 2019; 112:1684-1700. [DOI: 10.1111/mmi.14376] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/18/2019] [Indexed: 12/19/2022]
Affiliation(s)
- Elise Reus
- Department of Biotechnology and Bioengineering Technical University of Denmark Kongens Lyngby Denmark
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9
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Vassaux A, Meunier L, Vandenbol M, Baurain D, Fickers P, Jacques P, Leclère V. Nonribosomal peptides in fungal cell factories: from genome mining to optimized heterologous production. Biotechnol Adv 2019; 37:107449. [PMID: 31518630 DOI: 10.1016/j.biotechadv.2019.107449] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 09/06/2019] [Accepted: 09/09/2019] [Indexed: 12/15/2022]
Abstract
Fungi are notoriously prolific producers of secondary metabolites including nonribosomal peptides (NRPs). The structural complexity of NRPs grants them interesting activities such as antibiotic, anti-cancer, and anti-inflammatory properties. The discovery of these compounds with attractive activities can be achieved by using two approaches: either by screening samples originating from various environments for their biological activities, or by identifying the related clusters in genomic sequences thanks to bioinformatics tools. This genome mining approach has grown tremendously due to recent advances in genome sequencing, which have provided an incredible amount of genomic data from hundreds of microbial species. Regarding fungal organisms, the genomic data have revealed the presence of an unexpected number of putative NRP-related gene clusters. This highlights fungi as a goldmine for the discovery of putative novel bioactive compounds. Recent development of NRP dedicated bioinformatics tools have increased the capacity to identify these gene clusters and to deduce NRPs structures, speeding-up the screening process for novel metabolites discovery. Unfortunately, the newly identified compound is frequently not or poorly produced by native producers due to a lack of expression of the related genes cluster. A frequently employed strategy to increase production rates consists in transferring the related biosynthetic pathway in heterologous hosts. This review aims to provide a comprehensive overview about the topic of NRPs discovery, from gene cluster identification by genome mining to the heterologous production in fungal hosts. The main computational tools and methods for genome mining are herein presented with an emphasis on the particularities of the fungal systems. The different steps of the reconstitution of NRP biosynthetic pathway in heterologous fungal cell factories will be discussed, as well as the key factors to consider for maximizing productivity. Several examples will be developed to illustrate the potential of heterologous production to both discover uncharacterized novel compounds predicted in silico by genome mining, and to enhance the productivity of interesting bio-active natural products.
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Affiliation(s)
- Antoine Vassaux
- TERRA Teaching and Research Centre, Microbial Processes and Interactions, Gembloux Agro-Bio Tech, University of Liege, Avenue de la Faculté d'Agronomie, B5030 Gembloux, Belgium; Univ. Lille, INRA, ISA, Univ. Artois, Univ. Littoral Côte d'Opale, EA 7394-ICV-Institut Charles Viollette, F-59000 Lille, France
| | - Loïc Meunier
- TERRA Teaching and Research Centre, Microbial Processes and Interactions, Gembloux Agro-Bio Tech, University of Liege, Avenue de la Faculté d'Agronomie, B5030 Gembloux, Belgium; InBioS-PhytoSYSTEMS, Eukaryotic Phylogenomics, University of Liege, Boulevard du Rectorat 27, B-4000 Liège, Belgium
| | - Micheline Vandenbol
- TERRA Teaching and Research Centre, Microbiologie et Génomique, Gembloux Agro-Bio Tech, University of Liege, Avenue de la Faculté d'Agronomie, B5030 Gembloux, Belgium
| | - Denis Baurain
- InBioS-PhytoSYSTEMS, Eukaryotic Phylogenomics, University of Liege, Boulevard du Rectorat 27, B-4000 Liège, Belgium
| | - Patrick Fickers
- TERRA Teaching and Research Centre, Microbial Processes and Interactions, Gembloux Agro-Bio Tech, University of Liege, Avenue de la Faculté d'Agronomie, B5030 Gembloux, Belgium
| | - Philippe Jacques
- TERRA Teaching and Research Centre, Microbial Processes and Interactions, Gembloux Agro-Bio Tech, University of Liege, Avenue de la Faculté d'Agronomie, B5030 Gembloux, Belgium
| | - Valérie Leclère
- Univ. Lille, INRA, ISA, Univ. Artois, Univ. Littoral Côte d'Opale, EA 7394-ICV-Institut Charles Viollette, F-59000 Lille, France.
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Li L, Chen S, Gao M, Ding B, Zhang J, Zhou Y, Liu Y, Yang H, Wu Q, Chen F. Acidic conditions induce the accumulation of orange Monascus pigments during liquid-state fermentation of Monascus ruber M7. Appl Microbiol Biotechnol 2019; 103:8393-8402. [DOI: 10.1007/s00253-019-10114-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 08/14/2019] [Accepted: 08/30/2019] [Indexed: 12/12/2022]
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11
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Sensing and transduction of nutritional and chemical signals in filamentous fungi: Impact on cell development and secondary metabolites biosynthesis. Biotechnol Adv 2019; 37:107392. [PMID: 31034961 DOI: 10.1016/j.biotechadv.2019.04.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 04/22/2019] [Accepted: 04/25/2019] [Indexed: 11/23/2022]
Abstract
Filamentous fungi respond to hundreds of nutritional, chemical and environmental signals that affect expression of primary metabolism and biosynthesis of secondary metabolites. These signals are sensed at the membrane level by G protein coupled receptors (GPCRs). GPCRs contain usually seven transmembrane domains, an external amino terminal fragment that interacts with the ligand, and an internal carboxy terminal end interacting with the intracellular G protein. There is a great variety of GPCRs in filamentous fungi involved in sensing of sugars, amino acids, cellulose, cell-wall components, sex pheromones, oxylipins, calcium ions and other ligands. Mechanisms of signal transduction at the membrane level by GPCRs are discussed, including the internalization and compartmentalisation of these sensor proteins. We have identified and analysed the GPCRs in the genome of Penicillium chrysogenum and compared them with GPCRs of several other filamentous fungi. We have found 66 GPCRs classified into 14 classes, depending on the ligand recognized by these proteins, including most previously proposed classes of GPCRs. We have found 66 putative GPCRs, representatives of twelve of the fourteen previously proposed classes of GPCRs, depending on the ligand recognized by these proteins. A staggering fortytwo putative members of the new GPCR class XIV, the so-called Pth11 sensors of cellulosic material as reported for Neurospora crassa and some other fungi, were identified. Several GPCRs sensing sex pheromones, known in yeast and in several fungi, were also identified in P. chrysogenum, confirming the recent unravelling of the hidden sexual capacity of this species. Other sensing mechanisms do not involve GPCRs, including the two-component systems (HKRR), the HOG signalling system and the PalH mediated pH transduction sensor. GPCR sensor proteins transmit their signals by interacting with intracellular heterotrimeric G proteins, that are well known in several fungi, including P. chrysogenum. These G proteins are inactive in the GDP containing heterotrimeric state, and become active by nucleotide exchange, allowing the separation of the heterotrimeric protein in active Gα and Gβγ dimer subunits. The conversion of GTP in GDP is mediated by the endogenous GTPase activity of the G proteins. Downstream of the ligand interaction, the activated Gα protein and also the Gβ/Gγ dimer, transduce the signals through at least three different cascades: adenylate cyclase/cAMP, MAPK kinase, and phospholipase C mediated pathways.
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12
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Transcription Factors Controlling Primary and Secondary Metabolism in Filamentous Fungi: The β-Lactam Paradigm. FERMENTATION-BASEL 2018. [DOI: 10.3390/fermentation4020047] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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13
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Wang Y, Liu F, Wang L, Wang Q, Selvaraj JN, Zhao Y, Wang Y, Xing F, Liu Y. pH-Signaling Transcription Factor AopacC Regulates Ochratoxin A Biosynthesis in Aspergillus ochraceus. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:4394-4401. [PMID: 29651846 DOI: 10.1021/acs.jafc.8b00790] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
In Aspergillus and Penicillium species, an essential pH-response transcription factor pacC is involved in growth, pathogenicity, and toxigenicity. To investigate the connection between ochratoxin A (OTA) biosynthesis and ambient pH, the AopacC in Aspergillus ochraceus was functionally characterized using a loss-of-function mutant. The mycelium growth was inhibited under pH 4.5 and 10.0, while the sporulation increased under alkaline condition. A reduction of mycelium growth and an elevation of sporulation was observed in Δ AopacC mutant. Compared to neutral condition, OTA contents were respectively reduced by 71.6 and 79.8% under acidic and alkaline conditions. The expression of AopacC increased with the elevated pH, and deleting AopacC dramatically decreased OTA production and biosynthetic genes Aopks expression. Additionally, the Δ AopacC mutant exhibited attenuated infection ability toward pear fruits. These results suggest that AopacC is an alkaline-induced regulator responsible for growth and OTA biosynthesis in A. ochraceus and this regulatory mechanism might be pH-dependent.
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Affiliation(s)
- Yan Wang
- Institute of Food Science and Technology , Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture , No. 2 Yuanmingyuan West Road , Haidian District, Beijing 100193 , PR China
| | - Fei Liu
- Institute of Food Science and Technology , Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture , No. 2 Yuanmingyuan West Road , Haidian District, Beijing 100193 , PR China
- School of Food and Biological Engineering , Jiangsu University , Zhenjiang 212013 , PR China
| | - Liuqing Wang
- Institute of Food Science and Technology , Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture , No. 2 Yuanmingyuan West Road , Haidian District, Beijing 100193 , PR China
| | - Qi Wang
- Institute of Food Science and Technology , Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture , No. 2 Yuanmingyuan West Road , Haidian District, Beijing 100193 , PR China
| | - Jonathan Nimal Selvaraj
- Institute of Food Science and Technology , Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture , No. 2 Yuanmingyuan West Road , Haidian District, Beijing 100193 , PR China
| | - Yueju Zhao
- Institute of Food Science and Technology , Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture , No. 2 Yuanmingyuan West Road , Haidian District, Beijing 100193 , PR China
| | - Yun Wang
- School of Food and Biological Engineering , Jiangsu University , Zhenjiang 212013 , PR China
| | - Fuguo Xing
- Institute of Food Science and Technology , Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture , No. 2 Yuanmingyuan West Road , Haidian District, Beijing 100193 , PR China
| | - Yang Liu
- Institute of Food Science and Technology , Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture , No. 2 Yuanmingyuan West Road , Haidian District, Beijing 100193 , PR China
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Casein phosphopeptides and CaCl2 increase penicillin production and cause an increment in microbody/peroxisome proteins in Penicillium chrysogenum. J Proteomics 2017; 156:52-62. [DOI: 10.1016/j.jprot.2016.12.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 12/15/2016] [Accepted: 12/31/2016] [Indexed: 12/11/2022]
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Kiesenhofer D, Mach-Aigner AR, Mach RL. Understanding the Mechanism of Carbon Catabolite Repression to Increase Protein Production in Filamentous Fungi. Fungal Biol 2016. [DOI: 10.1007/978-3-319-27951-0_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Hu P, Wang Y, Zhou J, Pan Y, Liu G. AcstuA, which encodes an APSES transcription regulator, is involved in conidiation, cephalosporin biosynthesis and cell wall integrity of Acremonium chrysogenum. Fungal Genet Biol 2015; 83:26-40. [PMID: 26283234 DOI: 10.1016/j.fgb.2015.08.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 07/21/2015] [Accepted: 08/13/2015] [Indexed: 01/02/2023]
Abstract
A transcriptional regulatory gene AcstuA was identified from Acremonium chrysogenum. AcstuA encodes a basic helix-loop-helix protein with similarity to StuA which regulates the core developmental processes of Aspergillus nidulans. Like disruption of stuA in A. nidulans, deficiency of AcstuA blocked the conidiation of A. chrysogenum through severely down-regulating the expression of AcbrlA and AcabaA which encode orthologs of the key fungal developmental regulators BrlA and AbaA. Disruption of AcstuA also drastically reduced cephalosporin production of A. chrysogenum. In agreement, the transcriptions of pcbAB, pbcC, cefD1, cefD2, cefEF and cefG were remarkably decreased in the AcstuA disruption mutant (ΔAcstuA). In addition to defects in conidiation and cephalosporin biosynthesis, ΔAcstuA produced abnormal swollen and fragmented hyphal cells during fermentation. The phenotypic alterations of hyphal cells caused by AcstuA deletion were restored by supplementation of NaCl in the medium, indicating that the deficiency of AcstuA has an influence on the cell wall integrity of A. chrysogenum. The transcriptions of two putative mannoprotein encoding genes Acmp2 and Acmp3 significantly reduced in ΔAcstuA, further indicating that cell wall integrity of the mutant is impaired. These results strongly suggested that AcstuA is involved in conidiation, cephalosporin production, hyphal fragmentation and cell wall integrity in A. chrysogenum.
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Affiliation(s)
- Pengjie Hu
- University of Science and Technology of China (USTC), Hefei 230026, China; State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Ying Wang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jun Zhou
- Technical Centre of Beijing Cigarette Factory, Beijing 101121, China
| | - Yuanyuan Pan
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Gang Liu
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
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Domínguez-Santos R, García-Estrada C, Kosalková K, Prieto C, Santamarta I, Martín JF. PcFKH1, a novel regulatory factor from the forkhead family, controls the biosynthesis of penicillin in Penicillium chrysogenum. Biochimie 2015; 115:162-76. [PMID: 26049046 DOI: 10.1016/j.biochi.2015.05.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 05/18/2015] [Indexed: 11/17/2022]
Abstract
Penicillin biosynthesis in Penicillium chrysogenum (re-identified as Penicillium rubens) is a good example of a biological process subjected to complex global regulatory networks and serves as a model to study fungal secondary metabolism. The winged-helix family of transcription factors recently described, which includes the forkhead type of proteins, is a key type of regulatory proteins involved in this process. In yeasts and humans, forkhead transcription factors are involved in different processes (cell cycle regulation, cell death control, pre-mRNA processing and morphogenesis); one member of this family of proteins has been identified in the P. chrysogenum genome (Pc18g00430). In this work, we have characterized this novel transcription factor (named PcFKH1) by generating knock-down mutants and overexpression strains. Results clearly indicate that PcFKH1 positively controls antibiotic biosynthesis through the specific interaction with the promoter region of the penDE gene, thus regulating penDE mRNA levels. PcFKH1 also binds to the pcbC promoter, but with low affinity. In addition, it also controls other ancillary genes of the penicillin biosynthetic process, such as phlA (encoding phenylacetyl CoA ligase) and ppt (encoding phosphopantetheinyl transferase). PcFKH1 also plays a role in conidiation and spore pigmentation, but it does not seem to be involved in hyphal morphology or cell division in the improved laboratory reference strain Wisconsin 54-1255. A genome-wide analysis of processes putatively coregulated by PcFKH1 and PcRFX1 (another winged-helix transcription factor) in P. chrysogenum provided evidence of the global effect of these transcription factors in P. chrysogenum metabolism.
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Affiliation(s)
- Rebeca Domínguez-Santos
- Área de Microbiología, Departamento de Biología Molecular, Universidad de León, Campus de Vegazana s/n, 24071, León, Spain; INBIOTEC, Instituto de Biotecnología de León, Avda. Real nº. 1, Parque Científico de León, 24006, León, Spain
| | - Carlos García-Estrada
- INBIOTEC, Instituto de Biotecnología de León, Avda. Real nº. 1, Parque Científico de León, 24006, León, Spain.
| | - Katarina Kosalková
- INBIOTEC, Instituto de Biotecnología de León, Avda. Real nº. 1, Parque Científico de León, 24006, León, Spain
| | - Carlos Prieto
- Unidad de Bioinformática, Servicio NUCLEUS de Apoyo a la Investigación, Universidad de Salamanca (USAL), Edificio I+D+i, Calle Espejo, 2, 37007, Salamanca, Spain
| | - Irene Santamarta
- INBIOTEC, Instituto de Biotecnología de León, Avda. Real nº. 1, Parque Científico de León, 24006, León, Spain
| | - Juan-Francisco Martín
- Área de Microbiología, Departamento de Biología Molecular, Universidad de León, Campus de Vegazana s/n, 24071, León, Spain.
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Trpac1, a pH response transcription regulator, is involved in cellulase gene expression in Trichoderma reesei. Enzyme Microb Technol 2014; 67:17-26. [DOI: 10.1016/j.enzmictec.2014.08.013] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 08/26/2014] [Accepted: 08/27/2014] [Indexed: 11/21/2022]
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Sequencing, physical organization and kinetic expression of the patulin biosynthetic gene cluster from Penicillium expansum. Int J Food Microbiol 2014; 189:51-60. [PMID: 25120234 DOI: 10.1016/j.ijfoodmicro.2014.07.028] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Revised: 07/11/2014] [Accepted: 07/22/2014] [Indexed: 01/19/2023]
Abstract
Patulin is a polyketide-derived mycotoxin produced by numerous filamentous fungi. Among them, Penicillium expansum is by far the most problematic species. This fungus is a destructive phytopathogen capable of growing on fruit, provoking the blue mold decay of apples and producing significant amounts of patulin. The biosynthetic pathway of this mycotoxin is chemically well-characterized, but its genetic bases remain largely unknown with only few characterized genes in less economic relevant species. The present study consisted of the identification and positional organization of the patulin gene cluster in P. expansum strain NRRL 35695. Several amplification reactions were performed with degenerative primers that were designed based on sequences from the orthologous genes available in other species. An improved genome Walking approach was used in order to sequence the remaining adjacent genes of the cluster. RACE-PCR was also carried out from mRNAs to determine the start and stop codons of the coding sequences. The patulin gene cluster in P. expansum consists of 15 genes in the following order: patH, patG, patF, patE, patD, patC, patB, patA, patM, patN, patO, patL, patI, patJ, and patK. These genes share 60-70% of identity with orthologous genes grouped differently, within a putative patulin cluster described in a non-producing strain of Aspergillus clavatus. The kinetics of patulin cluster genes expression was studied under patulin-permissive conditions (natural apple-based medium) and patulin-restrictive conditions (Eagle's minimal essential medium), and demonstrated a significant association between gene expression and patulin production. In conclusion, the sequence of the patulin cluster in P. expansum constitutes a key step for a better understanding of the mechanisms leading to patulin production in this fungus. It will allow the role of each gene to be elucidated, and help to define strategies to reduce patulin production in apple-based products.
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Cepeda-García C, Domínguez-Santos R, García-Rico RO, García-Estrada C, Cajiao A, Fierro F, Martín JF. Direct involvement of the CreA transcription factor in penicillin biosynthesis and expression of the pcbAB gene in Penicillium chrysogenum. Appl Microbiol Biotechnol 2014; 98:7113-24. [PMID: 24818689 DOI: 10.1007/s00253-014-5760-1] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Revised: 04/03/2014] [Accepted: 04/05/2014] [Indexed: 01/29/2023]
Abstract
The transcription factor CreA is the main regulator responsible for carbon repression in filamentous fungi. CreA is a wide domain regulator that binds to regulatory elements in the promoters of target genes to repress their transcription. Penicillin biosynthesis and the expression of penicillin biosynthetic genes are subject to carbon repression. However, evidence of the participation of CreA in this regulation is still lacking, and previous studies on the promoter of the pcbC gene of Aspergillus nidulans indicated the lack of involvement of CreA in its regulation. Here we present clear evidence of the participation of CreA in carbon repression of penicillin biosynthesis and expression of the pcbAB gene, encoding the first enzyme of the pathway, in Penicillium chrysogenum. Mutations in cis of some of the putative CreA binding sites present in the pcbAB gene promoter fused to a reporter gene caused an important increase in the measured enzyme activity in glucose-containing medium, whereas activity in the medium with lactose was not affected. An RNAi strategy was used to attenuate the expression of the creA gene. Transformants expressing a small interfering RNA for creA showed higher penicillin production, and this increase was more evident when glucose was used as carbon source. These results confirm that CreA plays an important role in the regulation of penicillin biosynthesis in P. chrysogenum and opens the possibility of its utilization to improve the industrial production of this antibiotic.
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Affiliation(s)
- Cristina Cepeda-García
- Área de Microbiología, Facultad de Ciencias Biológicas y Ambientales, Universidad de León, León, Spain
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A new variant of self-excising β-recombinase/six cassette for repetitive gene deletion and homokaryon purification in Neurospora crassa. J Microbiol Methods 2014; 100:17-23. [DOI: 10.1016/j.mimet.2014.02.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Revised: 02/12/2014] [Accepted: 02/12/2014] [Indexed: 11/16/2022]
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Abstract
SIGNIFICANCE Postharvest pathogens can start its attack process immediately after spores land on wounded tissue, whereas other pathogens can forcibly breach the unripe fruit cuticle and then remain quiescent for months until fruit ripens and then cause major losses. RECENT ADVANCES Postharvest fungal pathogens activate their development by secreting organic acids or ammonia that acidify or alkalinize the host ambient surroundings. CRITICAL ISSUES These fungal pH modulations of host environment regulate an arsenal of enzymes to increase fungal pathogenicity. This arsenal includes genes and processes that compromise host defenses, contribute to intracellular signaling, produce cell wall-degrading enzymes, regulate specific transporters, induce redox protectant systems, and generate factors needed by the pathogen to effectively cope with the hostile environment found within the host. Further, evidence is accumulating that the secreted molecules (organic acids and ammonia) are multifunctional and together with effect of the ambient pH, they activate virulence factors and simultaneously hijack the plant defense response and induce program cell death to further enhance their necrotrophic attack. FUTURE DIRECTIONS Global studies of the effect of secreted molecules on fruit pathogen interaction, will determine the importance of these molecules on quiescence release and the initiation of fungal colonization leading to fruit and vegetable losses.
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Affiliation(s)
- Noam Alkan
- Department of Plant Sciences, Weizmann Institute of Science, Rehovot, Israel
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Glass NL, Schmoll M, Cate JH, Coradetti S. Plant Cell Wall Deconstruction by Ascomycete Fungi. Annu Rev Microbiol 2013; 67:477-98. [DOI: 10.1146/annurev-micro-092611-150044] [Citation(s) in RCA: 244] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
| | - Monika Schmoll
- Austrian Institute of Technology GmbH (AIT), Health and Environment, Bioresources, 3430 Tulln, Austria
| | - Jamie H.D. Cate
- Molecular and Cellular Biology Department, and
- Chemistry Department, University of California, Berkeley, California 94720;
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The pH signaling transcription factor PacC is required for full virulence in Penicillium digitatum. Appl Microbiol Biotechnol 2013; 97:9087-98. [PMID: 23917633 DOI: 10.1007/s00253-013-5129-x] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Revised: 07/07/2013] [Accepted: 07/12/2013] [Indexed: 01/27/2023]
Abstract
Penicillium digitatum is the most important postharvest pathogen of citrus fruits. Along disease progression, the infected citrus peel tissue is acidified due to the accumulation of organic acids. So far, relatively little is known about the environmental factors that regulate pathogenicity in this fungus. In this study, the role of the pH signaling transcription factor PacC in the pathogenesis of P. digitatum was investigated. We identified the pacC ortholog (PdpacC) in P. digitatum and found that its transcript levels were elevated under alkaline conditions (pH ≥ 7) in vitro, as well as during the infection of citrus fruits in spite of the low pH (about 3.0 to 3.5) of the macerated tissue. Na(+) and pectin also induced the expression of PdpacC. Disruption of PdpacC resulted in impaired mycelial growth under neutral or alkaline pH conditions and on synthetic medium supplemented with pectin as the sole carbon source, and attenuated virulence towards citrus fruits. Introducing the full length of PdpacC into the ΔPdpacC mutant restored all these phenotypes. The expression of the polygalacturonase gene Pdpg2 and pectin lyase gene Pdpnl1 in P. digitatum was upregulated in the wild type strain but not or weakly upregulated in the ΔPdpacC mutant during infection. Disruption of Pdpg2 also resulted in attenuated virulence of P. digitatum towards citrus fruits. Collectively, we conclude that PdPacC plays an important role in pathogenesis of P. digitatum via regulation of the expression of cell wall degradation enzyme genes, such as Pdpg2 and Pdpnl1.
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Prusky D, Alkan N, Mengiste T, Fluhr R. Quiescent and necrotrophic lifestyle choice during postharvest disease development. ANNUAL REVIEW OF PHYTOPATHOLOGY 2013; 51:155-76. [PMID: 23682917 DOI: 10.1146/annurev-phyto-082712-102349] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Insidious fungal infections by postharvest pathogens remain quiescent during fruit growth until, at a particular phase during fruit ripening and senescence, the pathogens switch to the necrotrophic lifestyle and cause decay. During ripening, fruits undergo physiological processes, such as activation of ethylene biosynthesis, cuticular changes, and cell-wall loosening-changes that are accompanied by a decline of antifungal compounds, both those that are preformed and those that are inducible secondary metabolites. Pathogen infection of the unripe host fruit initiates defensive signal-transduction cascades, culminating in accumulation of antifungal proteins that limit fungal growth and development. In contrast, development of the same pathogens during fruit ripening and storage activates a substantially different signaling network, one that facilitates aggressive fungal colonization. This review focuses on responses induced by the quiescent pathogens of postharvest diseases in unripe host fruits. New genome-scale experimental approaches have begun to delineate the complex and multiple networks of host and pathogen responses activated to maintain or to facilitate the transition from the quiescent to the necrotrophic lifestyle.
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Affiliation(s)
- Dov Prusky
- Department of Postharvest Science of Fresh Produce, ARO, Volcani Center, Bet Dagan, 50250 Israel.
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The inducers 1,3-diaminopropane and spermidine produce a drastic increase in the expression of the penicillin biosynthetic genes for prolonged time, mediated by the LaeA regulator. Fungal Genet Biol 2012; 49:1004-13. [DOI: 10.1016/j.fgb.2012.10.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Revised: 09/28/2012] [Accepted: 10/02/2012] [Indexed: 11/23/2022]
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Manteau S, Abouna S, Lambert B, Legendre L. Differential regulation by ambient pH of putative virulence factor secretion by the phytopathogenic fungus Botrytis cinerea. FEMS Microbiol Ecol 2012; 43:359-66. [PMID: 19719667 DOI: 10.1111/j.1574-6941.2003.tb01076.x] [Citation(s) in RCA: 125] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Abstract The fungal pathogen Botrytis cinerea is capable of developing on a wide variety of host plants that differ greatly in their pH values and biochemical defences. To evaluate whether the pH of the host tissue can regulate the production of pathogenicity factors by this fungus, we examined the ability of two isolates of B. cinerea that originated from different plant species to secrete putative virulence elements on synthetic media buffered at pH 2.0 to pH 7.0. Even though differing in the intensity of their responses, both isolates reacted similarly to their ambient pH. The production of extracellular polysaccharides and oxalic acid was detectable above pH 4.0 and pH 5.0 respectively. Conversely, the production of aspartic acid proteases could only be seen between pH 3.0 and 4.0. Finally, the secretion of polygalacturonase and laccase activity was found to exhibit two maxima, one around pH 3.1 and one around pH 6.0. Thus, pathogenicity factor production was found to be minimal between pH 4.5 and 5.5 and a different set of factors was produced at pH 3.1 and 6.0, two values that were found to correspond respectively to the average host fruit and leaf pH. These results demonstrate that ambient pH differentially regulates the synthesis of pathogenicity factors by Botrytis and may act as a novel regulatory element to assist this fungus in tuning its virulence machinery to the composition of its host tissue.
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Affiliation(s)
- Sebastien Manteau
- Laboratory of Plant Biology and Physiology, Plant Biochemistry and Molecular Biology Research Unit, University of Reims Champagne-Ardenne, URVVC-EA 2069, Moulin de la Housse, P.O. Box 1039, 51687 Reims Cedex 2, France
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Domínguez-Santos R, Martín JF, Kosalková K, Prieto C, Ullán RV, García-Estrada C. The regulatory factor PcRFX1 controls the expression of the three genes of β-lactam biosynthesis in Penicillium chrysogenum. Fungal Genet Biol 2012; 49:866-81. [PMID: 22960281 DOI: 10.1016/j.fgb.2012.08.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Revised: 08/02/2012] [Accepted: 08/04/2012] [Indexed: 10/27/2022]
Abstract
Penicillin biosynthesis is subjected to a complex regulatory network of signalling molecules that may serve as model for other secondary metabolites. The information provided by the new "omics" era about Penicillium chrysogenum and the advances in the knowledge of molecular mechanisms responsible for improved productivity, make this fungus an excellent model to decipher the mechanisms controlling the penicillin biosynthetic pathway. In this work, we have characterized a novel transcription factor PcRFX1, which is an ortholog of the Acremonium chrysogenum CPCR1 and Penicillium marneffei RfxA regulatory proteins. PcRFX1 DNA binding sequences were found in the promoter region of the pcbAB, pcbC and penDE genes. We show in this article that these motifs control the expression of the β-galactosidase lacZ reporter gene, indicating that they may direct the PcRFX1-mediated regulation of the penicillin biosynthetic genes. By means of Pcrfx1 gene knock-down and overexpression techniques we confirmed that PcRFX1 controls penicillin biosynthesis through the regulation of the pcbAB, pcbC and penDE transcription. Morphology and development seemed not to be controlled by this transcription factor under the conditions studied and only sporulation was slightly reduced after the silencing of the Pcrfx1 gene. A genome-wide analysis of processes putatively regulated by this transcription factor was carried out in P. chrysogenum. Results suggested that PcRFX1, in addition to regulate penicillin biosynthesis, is also involved in the control of several pathways of primary metabolism.
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Affiliation(s)
- Rebeca Domínguez-Santos
- Área de Microbiología, Departamento de Biología Molecular, Universidad de León, 24071 León, Spain
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Weber SS, Bovenberg RAL, Driessen AJM. Biosynthetic concepts for the production of β-lactam antibiotics in Penicillium chrysogenum. Biotechnol J 2011; 7:225-36. [PMID: 22057844 DOI: 10.1002/biot.201100065] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2011] [Revised: 08/12/2011] [Accepted: 08/24/2011] [Indexed: 11/08/2022]
Abstract
Industrial production of β-lactam antibiotics by the filamentous fungus Penicillium chrysogenum is based on successive classical strain improvement cycles. This review summarizes our current knowledge on the results of this classical strain improvement process, and discusses avenues to improve β-lactam biosynthesis and to exploit P. chrysogenum as an industrial host for the production of other antibiotics and peptide products. Genomic and transcriptional analysis of strain lineages has led to the identification of several important alterations in high-yielding strains, including the amplification of the penicillin biosynthetic gene cluster, elevated transcription of genes involved in biosynthesis of penicillin and amino acid precursors, and genes encoding microbody proliferation factors. In recent years, successful metabolic engineering and synthetic biology approaches have resulted in the redirection of the penicillin pathway towards the production of cephalosporins. This sets a new direction in industrial antibiotics productions towards more sustainable methods for the fermentative production of unnatural antibiotics and related compounds.
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Affiliation(s)
- Stefan S Weber
- Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology, University of Groningen, Zernike Institute for Advanced Materials and Kluyver Center for Genomics of Industrial Fermentation, AG Groningen, The Netherlands
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Regulation of trichothecene biosynthesis in Fusarium: recent advances and new insights. Appl Microbiol Biotechnol 2011; 91:519-28. [PMID: 21691790 DOI: 10.1007/s00253-011-3397-x] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2010] [Revised: 05/23/2011] [Accepted: 05/23/2011] [Indexed: 01/14/2023]
Abstract
Trichothecenes are toxic secondary metabolites produced by filamentous fungi mainly belonging to the Fusarium genus. Production of these mycotoxins occurs during infection of crops and is a threat to human and animal health. Although the pathway for biosynthesis of trichothecenes is well established, the regulation of the Tri genes implicated in the pathway remains poorly understood. Most of the Tri genes are gathered in a cluster which contains two transcriptional regulators controlling the expression of the other Tri genes. The regulation of secondary metabolites biosynthesis in most fungal genera has been recently shown to be controlled by various regulatory systems in response to external environment. The control of the "Tri cluster" by non-cluster regulators in Fusarium was not clearly demonstrated until recently. This review covers the recent advances concerning the regulation of trichothecene biosynthesis in Fusarium and highlights the potential implication of various general regulatory circuits. Further studies on the role of these regulatory systems in the control of trichothecene biosynthesis might be useful in designing new strategies to reduce mycotoxin accumulation.
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The molecular pathogenicity of Fusarium keratitis: a fungal transcriptional regulator promotes hyphal penetration of the cornea. Cornea 2011; 29:1440-4. [PMID: 20856109 DOI: 10.1097/ico.0b013e3181d8383a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
PURPOSE The pathogenic mechanisms of fungal infection during human keratomycosis were investigated in an ex vivo corneal model that used strains of Fusarium oxysporum differing in the production of a fungal transcription factor. METHODS A pacC loss-of-function mutant and a pacC dominant-activating mutant were constructed from a wild-type isolate of F. oxysporum, and the 3 strains were characterized by in vitro growth kinetics. Twenty-seven human donor corneas maintained in tissue culture were superficially scarified and topically inoculated with the wild-type, the pacC loss-of-function mutant, or the pacC dominant-activating strains. Relative hyphal invasion into the stroma was compared histopathologically in corneal sections. RESULTS F. oxysporum strains demonstrated comparable exponential growth rates in vitro. Wild-type F. oxysporum invaded into the corneal tissue within 1 day and penetrated through the anterior stroma during the next 4 days. The pacC loss-of-function mutant invaded explanted corneas significantly less than the wild-type strain on day 1 (P < 0.0001) and on day 3 (P = 0.0003). The pacC dominant-activating strain adhered and penetrated explanted corneas similar to the wild-type strain. CONCLUSIONS The PacC pathway regulating the transcription of fungal genes allows fungal adaptation to the ocular surface and enables invasion of the injured cornea by F. oxysporum.
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The pH regulatory factor Pac1 regulates Tri gene expression and trichothecene production in Fusarium graminearum. Fungal Genet Biol 2010; 48:275-84. [PMID: 21126599 DOI: 10.1016/j.fgb.2010.11.008] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Revised: 11/23/2010] [Accepted: 11/24/2010] [Indexed: 11/20/2022]
Abstract
Fungi manage the adaptation to extra-cellular pH through the PacC transcription factor, a key component of the pH regulatory system. PacC regulates the production of various secondary metabolites in filamentous fungi. In the important cereal pathogen Fusarium graminearum, the production of trichothecene is induced only under acidic pH conditions. Here, we examined the role of the PacC homologue from F. graminearum, FgPac1, on the regulation of trichothecene production. An FgΔPac1 deletion mutant was constructed in F. graminearum which showed a reduced development under neutral and alkaline pH, increased sensitivity to H(2)O(2) and an earlier Tri gene induction and toxin accumulation at acidic pH. A strain expressing the FgPac1(c) constitutively active form of Pac1 exhibited a strongly repressed Tri gene expression and reduced toxin accumulation at acidic pH. These results demonstrate that Pac1 negatively regulates Tri gene expression and toxin production in F. graminearum.
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Han YC, Li GQ, Yang L, Jiang DH. Molecular cloning, characterization and expression analysis of a pacC homolog in the mycoparasite Coniothyrium minitans. World J Microbiol Biotechnol 2010. [DOI: 10.1007/s11274-010-0469-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Zou CG, Tu HH, Liu XY, Tao N, Zhang KQ. PacC in the nematophagous fungus Clonostachys rosea controls virulence to nematodes. Environ Microbiol 2010; 12:1868-77. [PMID: 20236165 DOI: 10.1111/j.1462-2920.2010.02191.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Nematophagous fungi are commonly used as biological control agents of plant and animal parasitic nematodes. However, relatively little is known of the environmental attributes conferring pathogenicity in these fungi. In this report, we investigated the role of PacC-mediated pH response in the pathogenesis of the nematophagous fungus Clonostachys rosea. We identified a pacC orthologue from this fungus and found that its transcript was elevated in C. rosea during the early stage of its infection of nematode. Disruption of pacC resulted in slowed growth at alkaline pH, altered filamentation, reduced conidiation and attenuated virulence to nematodes. The expression of an extracellular serine protease PrC, a putative virulence factor, was downregulated in the pacC mutants. The PrC transcript levels were significantly higher under alkaline growth conditions than under acidic growth conditions. Promoter activity analysis and electrophoretic mobility shift assay indicated that the regulation of PrC by pH via the PacC pathway occurred at the transcriptional level. In conclusion, PacC functions as a positive regulator of virulence to nematodes in C. rosea.
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Affiliation(s)
- Cheng-Gang Zou
- Laboratory for Conservation and Utilization of Bio-Resources & Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, Yunnan 650091, China
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Brakhage AA, Thön M, Spröte P, Scharf DH, Al-Abdallah Q, Wolke SM, Hortschansky P. Aspects on evolution of fungal beta-lactam biosynthesis gene clusters and recruitment of trans-acting factors. PHYTOCHEMISTRY 2009; 70:1801-1811. [PMID: 19863978 DOI: 10.1016/j.phytochem.2009.09.011] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2009] [Revised: 09/10/2009] [Accepted: 09/11/2009] [Indexed: 05/28/2023]
Abstract
Penicillins and cephalosporins are beta-lactam antibiotics. The formation of hydrophobic penicillins has been reported in fungi only, notably Penicillium chrysogenum and Aspergillus (Emericella) nidulans, whereas the hydrophilic cephalosporins are produced by both fungi, e.g., Acremonium chrysogenum (cephalosporin C), and bacteria. The producing bacteria include Gram-negatives and Gram-positives, e.g., Streptomyces clavuligerus (cephamycin C) and Lysobacter lactamgenus (cephabacins), respectively. The evolutionary origin of beta-lactam biosynthesis genes has been the subject of discussion for many years, and two main hypotheses have been proposed: (i) horizontal gene transfer (HGT) from bacteria to fungi or (ii) vertical decent. There are strong arguments in favour of HGT, e.g., unlike most other fungal genes, beta-lactam biosynthesis genes are clustered and some of these genes lack introns. In contrast to S. clavuligerus, all regulators of fungal beta-lactam biosynthesis genes represent wide-domain regulators that are not part of the gene cluster. If bacterial regulators were co-transferred with the gene cluster from bacteria to fungi, most likely they would have been non-functional in eukaryotes and lost during evolution. Recently, the penicillin biosynthesis gene aatB was discovered, which is not part of the penicillin biosynthesis gene cluster and is even located on a different chromosome. The aatB gene is regulated by the same regulators AnCF and AnBH1 as the penicillin biosynthesis gene aatA (penDE). Data suggest that aatA and aatB are paralogues derived by duplication of a common ancestor gene. This data supports a model in which part of the beta-lactam biosynthesis gene cluster was transferred to some fungi, i.e., the acvA and ipnA gene without a regulatory gene. We propose that during the assembly of aatA and acvA-ipnA into a single gene cluster, recruitment of transcriptional regulators occurred along with acquisition of the duplicated aatA ancestor gene and its cis-acting sites.
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Affiliation(s)
- Axel A Brakhage
- Department of Molecular and Applied Microbiology, University of Jena, Jena, Germany.
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39
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Wang Q, Szaniszlo PJ. Roles of the pH signaling transcription factor PacC in Wangiella (Exophiala) dermatitidis. Fungal Genet Biol 2009; 46:657-66. [PMID: 19501183 DOI: 10.1016/j.fgb.2009.05.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2009] [Revised: 05/20/2009] [Accepted: 05/28/2009] [Indexed: 01/03/2023]
Abstract
To study the function of the PacC transcription factor in Wangiella dermatitidis, a black, polymorphic fungal pathogen of humans with yeast-phase predominance, the PACC gene was cloned, sequenced, disrupted and expressed. Three zinc finger DNA-binding motifs were found at the N-terminus, and a signaling protease cleavage site at the C-terminus. PACC was more expressed at neutral-alkaline pH than at acidic pH. Truncation at about 40 residues of the coding sequence upstream of the conserved protease processing cleavage site of PacC affected growth on a nutrient-rich medium, increased sensitivity to Na(+) stress, decreased yeast growth at neutral-alkaline pH, and repressed hyphal growth on a nutrient-poor medium at 25 degrees C. Truncation at the coding sequence for the conserved signaling protease box of PacC impaired growth and reduced RNA expression of the class II chitin synthase gene at acidic pH. The results suggested that PacC is important not only for the adaptation of W. dermatitidis to different ambient pH conditions and Na(+) stress conditions, but also for influencing yeast-hyphal transitions in this agent of phaeohyphomycosis.
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Affiliation(s)
- Qin Wang
- Section of Molecular Genetics and Microbiology, School of Biological Sciences and Institute of Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX 78712, USA
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40
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García-Rico RO, Fierro F, Mauriz E, Gómez A, Fernández-Bodega MÁ, Martín JF. The heterotrimeric Galpha protein pga1 regulates biosynthesis of penicillin, chrysogenin and roquefortine in Penicillium chrysogenum. MICROBIOLOGY-SGM 2008; 154:3567-3578. [PMID: 18957609 DOI: 10.1099/mic.0.2008/019091-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We have studied the role of the pga1 gene of Penicillium chrysogenum, encoding the alpha subunit of a heterotrimeric G protein, in secondary metabolite production. The dominant activating pga1(G42R) mutation caused an increase in the production of the three secondary metabolites penicillin, the yellow pigment chrysogenin and the mycotoxin roquefortine, whereas the dominant inactivating pga1(G203R) allele and the deletion of the pga1 gene resulted in a decrease of the amount of produced penicillin and roquefortine. Chrysogenin is produced in solid medium as a yellow pigment, and its biosynthesis is clearly enhanced by the presence of the dominant activating pga1(G42R) allele. Roquefortine is produced associated with mycelium during the first 3 days in submerged cultures, and is released to the medium afterwards; dominant activating and inactivating pga1 mutations result in upregulation and downregulation of roquefortine biosynthesis recpectively. Pga1 regulates penicillin biosynthesis by controlling expression of the penicillin biosynthetic genes; the three genes pcbAB, pcbC and penDE showed elevated transcript levels in transformants expressing the pga1(G42R) allele, whereas in transformants with the inactivating pga1(G203R) allele and in the pga1-deleted mutant their transcript levels were lower than those in the parental strains. Increase of intracellular cAMP levels had no effect on penicillin production. In summary, the dominant activating pga1(G42R) allele upregulates the biosynthesis of three secondary metabolites in Penicillium chrysogenum to a different extent.
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Affiliation(s)
- Ramón O García-Rico
- Área de Microbiología, Fac. CC. Biológicas y Ambientales, Universidad de León, León 24071, Spain.,Instituto de Biotecnología de León, INBIOTEC, Parque Científico de León, León 24006, Spain
| | - Francisco Fierro
- Área de Microbiología, Fac. CC. Biológicas y Ambientales, Universidad de León, León 24071, Spain.,Instituto de Biotecnología de León, INBIOTEC, Parque Científico de León, León 24006, Spain
| | - Elba Mauriz
- Instituto de Biotecnología de León, INBIOTEC, Parque Científico de León, León 24006, Spain
| | - Ana Gómez
- Instituto de Biotecnología de León, INBIOTEC, Parque Científico de León, León 24006, Spain
| | | | - Juan F Martín
- Área de Microbiología, Fac. CC. Biológicas y Ambientales, Universidad de León, León 24071, Spain.,Instituto de Biotecnología de León, INBIOTEC, Parque Científico de León, León 24006, Spain
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41
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Miyara I, Shafran H, Kramer Haimovich H, Rollins J, Sherman A, Prusky D. Multi-factor regulation of pectate lyase secretion by Colletotrichum gloeosporioides pathogenic on avocado fruits. MOLECULAR PLANT PATHOLOGY 2008; 9:281-91. [PMID: 18705870 PMCID: PMC6640356 DOI: 10.1111/j.1364-3703.2007.00462.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Tissue alkalinization during Colletotrichum gloeosporioides attack enhances the expression of PELB, which encodes pectate lyase (PL), and PL secretion, which is considered essential for full virulence. We studied the regulation of PL secretion by manipulation of C. gloeosporioides PELB. PELB was down-regulated by knocking out PAC1, which encodes the PacC transcription factor that regulates gene products with pH-sensitive activities. We functionally characterized a PACC gene homologue, PAC1, from C. gloeosporioides wild-type (WT) Cg-14 and two independent deletion strains, Deltapac1(372)and Deltapac1(761). Loss-of-function PAC1 mutants showed 85% reduction of PELB transcript expression, delayed PL secretion and dramatically reduced virulence, as detected in infection assays with avocado fruits. In contrast, PELB was up-regulated in the presence of carbon sources such as glucose. When glucose was used as a carbon source in the medium for the WT strain and the Deltapac1 mutant at pH 6.0, PELB transcript expression and PL secretion were activated. Other sugars, such as sucrose and fructose (but not galactose), also activated PELB expression. These results suggest that the pH-regulated response is only part of a multi-factor regulation of PELB, and that sugars are also needed to promote the transition from quiescent to active necrotrophic development by the pathogen.
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Affiliation(s)
- I Miyara
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, Volcani Center, Bet Dagan 50250, Israel
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42
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Shafran H, Miyara I, Eshed R, Prusky D, Sherman A. Development of new tools for studying gene function in fungi based on the Gateway system. Fungal Genet Biol 2008; 45:1147-54. [PMID: 18550398 DOI: 10.1016/j.fgb.2008.04.011] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2007] [Revised: 03/24/2008] [Accepted: 04/06/2008] [Indexed: 10/22/2022]
Abstract
Genomic information of many fungi has been released but large scale functional genomic studies are still limited by a lack of high-throughput methods. The low rates of homologous recombination and low rates of transformation are limiting steps in filamentous fungi, but the molecular tools are also lagging behind. In this paper we describe two new high-throughput functional genomic tools for filamentous fungi that are based on the Gateway technology. One system is the Gateway RNAi vector for fungi that allows gene silencing in a high-throughput manner. The other system is a high-throughput deletion construct system. These systems were tested using the PAC1 gene of Colletotrichum gloeosporioides. Using these types of approaches, large scale functional genomics experiments can be performed in filamentous fungi.
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Affiliation(s)
- Hadas Shafran
- Department of Genomics, Agricultural Research Organization, The Volcani Center, Bet Dagan 50250, Israel
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Meyer V. A small protein that fights fungi: AFP as a new promising antifungal agent of biotechnological value. Appl Microbiol Biotechnol 2007; 78:17-28. [PMID: 18066545 DOI: 10.1007/s00253-007-1291-3] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2007] [Revised: 11/14/2007] [Accepted: 11/15/2007] [Indexed: 11/28/2022]
Abstract
As fungal infections are becoming more prevalent in the medical or agricultural fields, novel and more efficient antifungal agents are badly needed. Within the scope of developing new strategies for the management of fungal infections, antifungal compounds that target essential fungal cell wall components are highly preferable. Ideally, newly developed antimycotics should also combine major aspects such as sustainability, high efficacy, limited toxicity and low costs of production. A naturally derived molecule that possesses all the desired characteristics is the antifungal protein (AFP) secreted by the filamentous ascomycete Aspergillus giganteus. AFP is a small, basic and cysteine-rich peptide that exerts extremely potent antifungal activity against human- and plant-pathogenic fungi without affecting the viability of bacteria, yeast, plant and mammalian cells. This review summarises the current knowledge of the structure, mode of action and expression of AFP, and highlights similarities and differences concerning these issues between AFP and its related proteins from other Ascomycetes. Furthermore, the potential use of AFP in the combat against fungal contaminations and infections will be discussed.
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Affiliation(s)
- Vera Meyer
- TU Berlin, Institut für Biotechnologie, Fachgebiet Mikrobiologie und Genetik, Gustav-Meyer-Allee 25, 13355, Berlin, Germany.
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44
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Kosalková K, Rodríguez-Sáiz M, Barredo JL, Martín JF. Binding of the PTA1 transcriptional activator to the divergent promoter region of the first two genes of the penicillin pathway in different Penicillium species. Curr Genet 2007; 52:229-37. [PMID: 17924108 DOI: 10.1007/s00294-007-0157-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2007] [Revised: 09/11/2007] [Accepted: 09/20/2007] [Indexed: 11/25/2022]
Abstract
The aim of this work is to establish the correlation between the transcriptional activator PTA1 and the expression of the penicillin genes in different penicillin-producing strains. The level of expression of the first two genes of the penicillin pathway was clearly higher in Penicillium chrysogenum than in Penicillium notatum and Penicillium nalgiovense. The divergent promoter pcbAB-pcbC region contains binding sequences for several transcriptional factors that are conserved in P. notatum and P. chrysogenum, but not in P. nalgiovense. Binding of the purified P. chrysogenum transcriptional activator PTA1 to the palindromic heptamer TTAGTAA took place when the P. chrysogenum 35 bp DNA fragment containing the heptamer was used as a probe, but not when the sequence occurring in P. nalgiovense was used. P. nalgiovense protein fractions purified by heparin agarose chromatography did not bind to the 35-bp DNA fragment either from P. nalgiovense or P. chrysogenum, although some degree of binding was observed when crude extracts were used. This finding may explain the low expression of pcbC in P. nalgiovense. All the P. chrysogenum strains, including the industrial strain E1, showed the same nucleotide sequence, including the consensus PTA1 binding site.
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Affiliation(s)
- Katarina Kosalková
- INBIOTEC, Parque Científico de León, Instituto de Biotecnología de León, Av. Real, 1, 24006, León, Spain
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45
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van den Berg MA, Westerlaken I, Leeflang C, Kerkman R, Bovenberg RAL. Functional characterization of the penicillin biosynthetic gene cluster of Penicillium chrysogenum Wisconsin54-1255. Fungal Genet Biol 2007; 44:830-44. [PMID: 17548217 DOI: 10.1016/j.fgb.2007.03.008] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2006] [Revised: 03/17/2007] [Accepted: 03/23/2007] [Indexed: 11/28/2022]
Abstract
Industrial strain improvement via classical mutagenesis is a black box approach. In an attempt to learn from and understand the mutations introduced, we cloned and characterized the amplified region of industrial penicillin production strains. Upon amplification of this region Penicillium chrysogenum is capable of producing an increased amount of antibiotics, as was previously reported [Barredo, J.L., Diez, B., Alvarez, E., Martín, J.F., 1989a. Large amplification of a 35-kb DNA fragment carrying two penicillin biosynthetic genes in high yielding strains of Penicillium chrysogenum. Curr. Genet. 16, 453-459; Newbert, R.W., Barton, B., Greaves, P., Harper, J., Turner, G., 1997. Analysis of a commercially improved Penicillium chrysogenum strain series, involvement of recombinogenic regions in amplification and deletion of the penicillin gene cluster. J. Ind. Microbiol. 19, 18-27]. Bioinformatic analysis of the central 56.9kb, present as six direct repeats in the strains analyzed in this study, predicted 15 Open Reading Frames (ORFs). Besides the three penicillin biosynthetic genes (pcbAB, pcbC and penDE) only one ORF has an orthologue of known function in the database: the Saccharomyces cerevisiae gene ERG25. Surprisingly, many genes known to encode direct or indirect steps beta-lactam biosynthesis like phenyl acetic acid CoA ligase and transporters are not present. Detailed analyses reveal a detectable transcript for most of the predicted ORFs under the conditions tested. We have studied the role of these in relation to penicillin production and amplification of the biosynthetic gene cluster. In contrast to what was expected, the genes encoding the three penicillin biosynthetic enzymes alone are sufficient to restore full beta-lactam synthesis in a mutant lacking the complete region. Therefore, the role of the other 12 ORFs in this region seems irrelevant for penicillin biosynthesis.
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Affiliation(s)
- Marco A van den Berg
- DSM Anti-Infectives, DSM Gist (624-0270), P.O. Box 425, 2600 AK, Delft, The Netherlands.
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You BJ, Choquer M, Chung KR. The Colletotrichum acutatum gene encoding a putative pH-responsive transcription regulator is a key virulence determinant during fungal pathogenesis on citrus. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2007; 20:1149-60. [PMID: 17849717 DOI: 10.1094/mpmi-20-9-1149] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Postbloom fruit drop of citrus and Key lime anthracnose (KLA) are caused by different pathotypes of Colletotrichum acutatum. Both pathotypes are pathogenic to citrus flowers, resulting in blossom blight and induction of young fruit abscission. Two fungal mutants defective in pathogenicity were recovered from a KLA pathotype after Agrobacterium-mediated mutagenesis. A PacC(KLAP2) gene encoding a polypeptide that resembles many pH-responsive PacC/ Rim101 transcription regulators in fungi was identified from one of the mutants, and functionally characterized to play a crucial role in pathogenesis to both Key lime leaves and citrus flowers. Gene disruption at the Pac(KLAP2) locus created fungal mutants that were hypersensitive to alkaline pH, altered in conidium and appressorium production and germination, and concomitant with reduced virulence to both tissues. The pacC(KLAP2) null mutants had lower alkaline phosphatase and protease activities, but increased pectolytic and lipolytic activities. The mutants initiated penetration and incited lesion formation on Key lime, indistinguishable from the wild type, when a functional copy of PacC(KLAP2) was reintroduced or the leaves were wounded prior to inoculation. The null mutants were blocked at the penetration stage and, thus, failed to initiate the necrotrophic phase. The PacC(KLAP2) transcript was barely detectable when the fungus was grown on medium buffered to pH 3 or 4, yet accumulated to high levels at a pH between 5 and 7. The Pac(KLAP2) transcript was detected 2 days postinoculation on Key lime leaves, correlating with the time of lesion formation. We conclude that PacC(KLAP2) is essential for C. acutatum pathogenesis by regulating multiple physiological and developmental processes.
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Affiliation(s)
- Bang-Jau You
- Citrus Research and Education Center and Department of Plant Pathology, Institute of Food and Agricultural Sciences (IFAS), University of Florida, 700 Experiment Station Road, Lake Alfred, FL 33850, USA
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Biswas S, Van Dijck P, Datta A. Environmental sensing and signal transduction pathways regulating morphopathogenic determinants of Candida albicans. Microbiol Mol Biol Rev 2007; 71:348-76. [PMID: 17554048 PMCID: PMC1899878 DOI: 10.1128/mmbr.00009-06] [Citation(s) in RCA: 392] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Candida albicans is an opportunistic fungal pathogen that is found in the normal gastrointestinal flora of most healthy humans. However, under certain environmental conditions, it can become a life-threatening pathogen. The shift from commensal organism to pathogen is often correlated with the capacity to undergo morphogenesis. Indeed, under certain conditions, including growth at ambient temperature, the presence of serum or N-acetylglucosamine, neutral pH, and nutrient starvation, C. albicans can undergo reversible transitions from the yeast form to the mycelial form. This morphological plasticity reflects the interplay of various signal transduction pathways, either stimulating or repressing hyphal formation. In this review, we provide an overview of the different sensing and signaling pathways involved in the morphogenesis and pathogenesis of C. albicans. Where appropriate, we compare the analogous pathways/genes in Saccharomyces cerevisiae in an attempt to highlight the evolution of the different components of the two organisms. The downstream components of these pathways, some of which may be interesting antifungal targets, are also discussed.
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Affiliation(s)
- Subhrajit Biswas
- National Centre for Plant Genome Research, New Delhi 110 067, India
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Meyer V, Spielvogel A, Funk L, Tilburn J, Arst HN, Stahl U. Alkaline pH-induced up-regulation of the afp gene encoding the antifungal protein (AFP) of Aspergillus giganteus is not mediated by the transcription factor PacC: possible involvement of calcineurin. Mol Genet Genomics 2005; 274:295-306. [PMID: 16133167 DOI: 10.1007/s00438-005-0002-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2005] [Accepted: 04/22/2005] [Indexed: 10/25/2022]
Abstract
The afp gene encoding the antifungal protein (AFP) of Aspergillus giganteus has a prototypical alkaline gene expression pattern, which suggests that the gene might be under the control of the ambient pH-dependent zinc-finger transcription factor PacC. This notion is corroborated by the presence in the upstream region of afp of two putative PacC binding sites, afpP1 and afpP2, which are specifically recognised by the PacC protein of A. nidulans in vitro. However, in this report we provide several lines of evidence to show that pH-dependent up-regulation of afp is not mediated by transcriptional activation through PacC. (1) The temporal expression pattern of the A. giganteus pacC gene does not parallel the accumulation of the afp mRNA during cultivation. (2) Inactivation of afpP1 and afpP2 did not reduce promoter activity under alkaline conditions, as determined from the relative wild-type and mutant afp::lacZ reporter activities in A. nidulans. (3) Reporter activities in acidity- and alkalinity-mimicking mutant strains are inconsistent with a positive role for PacC in afp expression. (4) In A. giganteus, the pH-dependent increase in afp mRNA and AFP levels can be completely prevented by the calcineurin inhibitor FK506, suggesting that the calcineurin signalling pathway might control the in vivo activation of the afp promoter by alkaline pH.
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Affiliation(s)
- Vera Meyer
- Institut für Biotechnologie, Fachgebiet Mikrobiologie und Genetik, Technische Universität Berlin, Germany.
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Brakhage AA, Al-Abdallah Q, Tüncher A, Spröte P. Evolution of beta-lactam biosynthesis genes and recruitment of trans-acting factors. PHYTOCHEMISTRY 2005; 66:1200-10. [PMID: 15950251 DOI: 10.1016/j.phytochem.2005.02.030] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2004] [Revised: 02/03/2005] [Accepted: 02/03/2005] [Indexed: 05/02/2023]
Abstract
Penicillins and cephalosporins belong chemically to the group of beta-lactam antibiotics. The formation of hydrophobic penicillins has been reported in fungi only, notably Penicillium chrysogenum and Emericella nidulans, whereas the hydrophilic cephalosporins are produced by both fungi, e.g., Acremonium chrysogenum (cephalosporin C), and bacteria. The producing bacteria include Gram-negatives and Gram-positives, e.g. Lysobacter lactamdurans (cephabacins) and Streptomyces clavuligerus (cephamycin C), respectively. For a long time the evolutionary origin of beta-lactam biosynthesis genes in fungi has been discussed. As often, there are arguments for both hypotheses, i.e., horizontal gene transfer from bacteria to fungi versus vertical descent. There were strong arguments in favour of horizontal gene transfer, e.g., fungal genes were clustered or some genes lack introns. The recent identification and characterisation of cis-/trans-elements involved in the regulation of the beta-lactam biosynthesis genes has provided new arguments in favour of horizontal gene transfer. In contrast to the bacterium S. clavuligerus, all regulators of fungal beta-lactam biosynthesis genes represent wide-domain regulators which were recruited to also regulate the beta-lactam biosynthesis genes. Moreover, the fungal regulatory genes are not part of the gene cluster. If bacterial regulators were co-transferred with the gene cluster from bacteria to fungi, most likely they would have been non-functional in eukaryotes and lost during evolution. Alternatively, it is conceivable that only a part of the beta-lactam biosynthesis gene cluster was transferred to some fungi, e.g., the acvA and ipnA gene without a regulatory gene.
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Affiliation(s)
- Axel A Brakhage
- Department of Molecular and Applied Microbiology, Leibniz-Institute for Natural Products Research and Infection Biology, Hans-Knoell-Institute, Beutenbergstrasse 11a, D-07745 Jena, Germany.
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Aro N, Pakula T, Penttilä M. Transcriptional regulation of plant cell wall degradation by filamentous fungi. FEMS Microbiol Rev 2004; 29:719-39. [PMID: 16102600 DOI: 10.1016/j.femsre.2004.11.006] [Citation(s) in RCA: 274] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2004] [Revised: 10/29/2004] [Accepted: 11/01/2004] [Indexed: 11/22/2022] Open
Abstract
Plant cell wall consists mainly of the large biopolymers cellulose, hemicellulose, lignin and pectin. These biopolymers are degraded by many microorganisms, in particular filamentous fungi, with the aid of extracellular enzymes. Filamentous fungi have a key role in degradation of the most abundant biopolymers found in nature, cellulose and hemicelluloses, and therefore are essential for the maintenance of the global carbon cycle. The production of plant cell wall degrading enzymes, cellulases, hemicellulases, ligninases and pectinases, is regulated mainly at the transcriptional level in filamentous fungi. The genes are induced in the presence of the polymers or molecules derived from the polymers and repressed under growth conditions where the production of these enzymes is not necessary, such as on glucose. The expression of the genes encoding the enzymes is regulated by various environmental and cellular factors, some of which are common while others are more unique to either a certain fungus or a class of enzymes. This review summarises our current knowledge on the transcriptional regulation, focusing on the recently characterized transcription factors that regulate genes coding for enzymes involved in the breakdown of plant cell wall biopolymers.
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Affiliation(s)
- Nina Aro
- VTT Biotechnology, Espoo, Finland.
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