1
|
Lin SY, Oakley CE, Jenkinson CB, Chiang YM, Lee CK, Jones CG, Seidler PM, Nelson HM, Todd RB, Wang CCC, Oakley BR. A heterologous expression platform in Aspergillus nidulans for the elucidation of cryptic secondary metabolism biosynthetic gene clusters: discovery of the Aspergillus fumigatus sartorypyrone biosynthetic pathway. Chem Sci 2023; 14:11022-11032. [PMID: 37860661 PMCID: PMC10583710 DOI: 10.1039/d3sc02226a] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Accepted: 06/26/2023] [Indexed: 10/21/2023] Open
Abstract
Aspergillus fumigatus is a serious human pathogen causing life-threatening Aspergillosis in immunocompromised patients. Secondary metabolites (SMs) play an important role in pathogenesis, but the products of many SM biosynthetic gene clusters (BGCs) remain unknown. In this study, we have developed a heterologous expression platform in Aspergillus nidulans, using a newly created genetic dereplication strain, to express a previously unknown BGC from A. fumigatus and determine its products. The BGC produces sartorypyrones, and we have named it the spy BGC. Analysis of targeted gene deletions by HRESIMS, NMR, and microcrystal electron diffraction (MicroED) enabled us to identify 12 products from the spy BGC. Seven of the compounds have not been isolated previously. We also individually expressed the polyketide synthase (PKS) gene spyA and demonstrated that it produces the polyketide triacetic acid lactone (TAL), a potentially important biorenewable platform chemical. Our data have allowed us to propose a biosynthetic pathway for sartorypyrones and related natural products. This work highlights the potential of using the A. nidulans heterologous expression platform to uncover cryptic BGCs from A. fumigatus and other species, despite the complexity of their secondary metabolomes.
Collapse
Affiliation(s)
- Shu-Yi Lin
- Department of Pharmacology and Pharmaceutical Sciences, University of Southern California Los Angeles CA 90089 USA
| | - C Elizabeth Oakley
- Department of Molecular Biosciences, University of Kansas 1200 Sunnyside Avenue Lawrence KS 66045 USA
| | - Cory B Jenkinson
- Department of Molecular Biosciences, University of Kansas 1200 Sunnyside Avenue Lawrence KS 66045 USA
| | - Yi-Ming Chiang
- Department of Pharmacology and Pharmaceutical Sciences, University of Southern California Los Angeles CA 90089 USA
| | - Ching-Kuo Lee
- School of Pharmacy, College of Pharmacy, Taipei Medical University Taipei 11031 Taiwan
| | - Christopher G Jones
- The Arnold and Mabel Beckman Laboratory of Chemical Synthesis, Division of Chemistry and Chemical Engineering, California Institute of Technology Pasadena California 91125 USA
| | - Paul M Seidler
- Department of Pharmacology and Pharmaceutical Sciences, University of Southern California Los Angeles CA 90089 USA
| | - Hosea M Nelson
- The Arnold and Mabel Beckman Laboratory of Chemical Synthesis, Division of Chemistry and Chemical Engineering, California Institute of Technology Pasadena California 91125 USA
| | - Richard B Todd
- Department of Plant Pathology, Kansas State University Manhattan KS 66506 USA
| | - Clay C C Wang
- Department of Pharmacology and Pharmaceutical Sciences, University of Southern California Los Angeles CA 90089 USA
- Department of Chemistry, University of Southern California Los Angeles CA 90089 USA
| | - Berl R Oakley
- Department of Molecular Biosciences, University of Kansas 1200 Sunnyside Avenue Lawrence KS 66045 USA
| |
Collapse
|
2
|
Chang PK. A Simple CRISPR/Cas9 System for Efficiently Targeting Genes of Aspergillus Section Flavi Species, Aspergillus nidulans, Aspergillus fumigatus, Aspergillus terreus, and Aspergillus niger. Microbiol Spectr 2023; 11:e0464822. [PMID: 36651760 PMCID: PMC9927283 DOI: 10.1128/spectrum.04648-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 12/23/2022] [Indexed: 01/19/2023] Open
Abstract
For Aspergillus flavus, a pathogen of considerable economic and health concern, successful gene knockout work for more than a decade has relied nearly exclusively on using nonhomologous end-joining pathway (NHEJ)-deficient recipients via forced double-crossover recombination of homologous sequences. In this study, a simple CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/CRISPR-associated nuclease) genome editing system that gave extremely high (>95%) gene-targeting frequencies in A. flavus was developed. It contained a shortened Aspergillus nidulans AMA1 autonomously replicating sequence that maintained good transformation frequencies and Aspergillus oryzae ptrA as the selection marker for pyrithiamine resistance. Expression of the codon-optimized cas9 gene was driven by the A. nidulans gpdA promoter and trpC terminator. Expression of single guide RNA (sgRNA) cassettes was controlled by the A. flavus U6 promoter and terminator. The high transformation and gene-targeting frequencies of this system made generation of A. flavus gene knockouts with or without phenotypic changes effortless. Additionally, multiple-gene knockouts of A. flavus conidial pigment genes (olgA/copT/wA or olgA/yA/wA) were quickly generated by a sequential approach. Cotransforming sgRNA vectors targeting A. flavus kojA, yA, and wA gave 52%, 40%, and 8% of single-, double-, and triple-gene knockouts, respectively. The system was readily applicable to other section Flavi aspergilli (A. parasiticus, A. oryzae, A. sojae, A. nomius, A. bombycis, and A. pseudotamarii) with comparable transformation and gene-targeting efficiencies. Moreover, it gave satisfactory gene-targeting efficiencies (>90%) in A. nidulans (section Nidulantes), A. fumigatus (section Fumigati), A. terreus (section Terrei), and A. niger (section Nigri). It likely will have a broad application in aspergilli. IMPORTANCE CRISPR/Cas9 genome editing systems have been developed for many aspergilli. Reported gene-targeting efficiencies vary greatly and are dependent on delivery methods, repair mechanisms of induced double-stranded breaks, selection markers, and genetic backgrounds of transformation recipient strains. They are also mostly strain specific or species specific. This developed system is highly efficient and allows knocking out multiple genes in A. flavus efficiently either by sequential transformation or by cotransformation of individual sgRNA vectors if desired. It is readily applicable to section Flavi species and aspergilli in other sections ("section" is a taxonomic rank between genus and species). This cross-Aspergillus section system is for wild-type isolates and does not require homologous donor DNAs to be added, NHEJ-deficient strains to be created, or forced recycling of knockout recipients to be performed for multiple-gene targeting. Hence, it simplifies and expedites the gene-targeting process significantly.
Collapse
Affiliation(s)
- Perng-Kuang Chang
- Southern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, New Orleans, Louisiana, USA
| |
Collapse
|
3
|
Yoshimura Y, Kobayashi Y, Kawaguchi T, Tani S. Improvement of cellulosic biomass-degrading enzyme production by reducing extracellular protease production in <i>Aspergillus aculeatus</i>. J GEN APPL MICROBIOL 2022; 68:143-150. [DOI: 10.2323/jgam.2021.10.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Yuko Yoshimura
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University
| | - Yuri Kobayashi
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University
| | - Takashi Kawaguchi
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University
| | - Shuji Tani
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University
| |
Collapse
|
4
|
Men P, Wang M, Li J, Geng C, Huang X, Lu X. Establishing an Efficient Genetic Manipulation System for Sulfated Echinocandin Producing Fungus Coleophoma empetri. Front Microbiol 2021; 12:734780. [PMID: 34489920 PMCID: PMC8417879 DOI: 10.3389/fmicb.2021.734780] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 07/28/2021] [Indexed: 11/15/2022] Open
Abstract
Micafungin is an important echinocandin antifungal agent for the treatment of invasive fungal infections. In industry, micafungin is derived from the natural product FR901379, which is a non-ribosomal cyclic hexapeptide produced by the filamentous fungus Coleophoma empetri. The difficulty of genetic manipulation in C. empetri restricts the clarification of FR901379 biosynthetic mechanism. In this work, we developed an efficient genetic manipulation system in the industrial FR901379-producing strain C. empetri MEFC009. Firstly, a convenient protoplast-mediated transformation (PMT) method was developed. Secondly, with this transformation method, the essential genetic elements were verified. Selectable markers hph, neo, and nat can be used for the transformation, and promotors Ppgk, PgpdA, and PgpdAt are functional in C. empetri MEFC009. Thirdly, the frequency of homologous recombination was improved from 4 to 100% by deleting the ku80 gene, resulting in an excellent chassis cell for gene-targeting. Additionally, the advantage of this genetic manipulation system was demonstrated in the identification of the polyketide synthase (PKS) responsible for the biosynthesis of dihydroxynapthalene (DHN)-melanin. This genetic manipulation system will be a useful platform for the research of FR901379 and further genome mining of secondary metabolites in C. empetri.
Collapse
Affiliation(s)
- Ping Men
- Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China.,Shandong Energy Institute, Qingdao, China.,Qingdao New Energy Shandong Laboratory, Qingdao, China.,College of Life Science, University of Chinese Academy of Sciences, Beijing, China
| | - Min Wang
- Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China.,Shandong Energy Institute, Qingdao, China.,Qingdao New Energy Shandong Laboratory, Qingdao, China
| | - Jinda Li
- Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China.,Shandong Energy Institute, Qingdao, China.,Qingdao New Energy Shandong Laboratory, Qingdao, China
| | - Ce Geng
- Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China.,Shandong Energy Institute, Qingdao, China.,Qingdao New Energy Shandong Laboratory, Qingdao, China
| | - Xuenian Huang
- Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China.,Shandong Energy Institute, Qingdao, China.,Qingdao New Energy Shandong Laboratory, Qingdao, China
| | - Xuefeng Lu
- Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China.,Shandong Energy Institute, Qingdao, China.,Qingdao New Energy Shandong Laboratory, Qingdao, China.,College of Life Science, University of Chinese Academy of Sciences, Beijing, China.,Marine Biology and Biotechnology Laboratory, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
| |
Collapse
|
5
|
Yamashita M, Tsujikami M, Murata S, Kobayashi T, Shimizu M, Kato M. Artificial AmyR::XlnR transcription factor induces α-amylase production in response to non-edible xylan-containing hemicellulosic biomass. Enzyme Microb Technol 2021; 145:109762. [PMID: 33750542 DOI: 10.1016/j.enzmictec.2021.109762] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 01/22/2021] [Accepted: 02/04/2021] [Indexed: 12/17/2022]
Abstract
Filamentous fungi belonging to the Aspergillus genus are one of the most favored microorganisms for industrial enzyme production because they can secrete large amounts of proteins into the culture medium. α-Amylase, an enzyme produced by Aspergillus species, is important for food and industrial applications. The production of α-amylase is induced by starch, mainly obtained from the edible biomass; however, the increasing demand for foods is limiting the application of the latter. Therefore, it is expected that using the non-edible biomass, such as rice straw, could improve the competition for industrial application starch containing resources. The transcription factor AmyR activates the transcription of amylolytic enzyme genes, while the transcription factor XlnR activates the transcription of xylanolytic enzyme genes in response to xylose. In this study, we aimed to construct an artificial AmyR::XlnR transcription factor (AXTF) by replacing the DNA-binding domain (1-159 amino acids) of XlnR with that (1-68 aa) of AmyR, which is capable of inducing amylolytic enzyme production in response to xylan-containing hemicellulosic biomass. The chimeric transcription factor AXTF was constructed and expressed using the gapA promoter in the amyR-deficient mutant strain SA1. When the AXTF strain was cultured in the minimal medium containing xylose as the carbon source, the amyB, amyF, agdB, and agdE transcription levels were 41.1-, 11.3-, 37.9-, and 23.7-fold higher, respectively, than those of the wild-type strain. The α-amylase and α-glucosidase activities in the culture supernatant of the AXTF strain grown with xylose for 48 h were 696.6 and 536.1 U/mL, respectively, while these activities were not detected in the culture supernatant of the wild-type and SA1 strains. When rice straw hydrolysate was used as a carbon source, the α-amylase and α-glucosidase activities were 590.2 and 362.7 U/mL, respectively. Thus, we successfully generated an Aspergillus nidulans strain showing amylolytic enzyme production in response to non-edible xylan-containing hemicellulosic biomass by transforming it with the chimeric transcription factor AXTF. Furthermore, the use of genes encoding engineered transcription factors is advantageous because introducing such genes into an industrial Aspergillus strain has similar simultaneous effects on multiple amylase genes controlled by AmyR.
Collapse
Affiliation(s)
- Miharu Yamashita
- Faculty of Agriculture, Meijo University, Shiogamaguchi, Tenpaku-ku, Nagoya, Aichi, 468-8502, Japan
| | - Masaya Tsujikami
- Faculty of Agriculture, Meijo University, Shiogamaguchi, Tenpaku-ku, Nagoya, Aichi, 468-8502, Japan
| | - Shunsuke Murata
- Faculty of Agriculture, Meijo University, Shiogamaguchi, Tenpaku-ku, Nagoya, Aichi, 468-8502, Japan
| | - Tetsuo Kobayashi
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan
| | - Motoyuki Shimizu
- Faculty of Agriculture, Meijo University, Shiogamaguchi, Tenpaku-ku, Nagoya, Aichi, 468-8502, Japan
| | - Masashi Kato
- Faculty of Agriculture, Meijo University, Shiogamaguchi, Tenpaku-ku, Nagoya, Aichi, 468-8502, Japan.
| |
Collapse
|
6
|
LaeA Controls Citric Acid Production through Regulation of the Citrate Exporter-Encoding cexA Gene in Aspergillus luchuensis mut. kawachii. Appl Environ Microbiol 2020; 86:AEM.01950-19. [PMID: 31862728 DOI: 10.1128/aem.01950-19] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Accepted: 12/17/2019] [Indexed: 11/20/2022] Open
Abstract
The putative methyltransferase LaeA is a global regulator of metabolic and development processes in filamentous fungi. We characterized the homologous laeA genes of the white koji fungus Aspergillus luchuensis mut. kawachii (A. kawachii) to determine their role in citric acid hyperproduction. The ΔlaeA strain exhibited a significant reduction in citric acid production. Cap analysis gene expression (CAGE) revealed that laeA is required for the expression of a putative citrate exporter-encoding cexA gene, which is critical for citric acid production. Deficient citric acid production by a ΔlaeA strain was rescued by the overexpression of cexA to a level comparable with that of a cexA-overexpressing ΔcexA strain. In addition, chromatin immunoprecipitation coupled with quantitative PCR (ChIP-qPCR) analysis indicated that LaeA regulates the expression of cexA via methylation levels of the histones H3K4 and H3K9. These results indicate that LaeA is involved in citric acid production through epigenetic regulation of cexA in A. kawachii IMPORTANCE A. kawachii has been traditionally used for production of the distilled spirit shochu in Japan. Citric acid produced by A. kawachii plays an important role in preventing microbial contamination during the shochu fermentation process. This study characterized homologous laeA genes; using CAGE, complementation tests, and ChIP-qPCR, it was found that laeA is required for citric acid production through the regulation of cexA in A. kawachii The epigenetic regulation of citric acid production elucidated in this study will be useful for controlling the fermentation processes of shochu.
Collapse
|
7
|
Zhang H, Yan JN, Zhang H, Liu TQ, Xu Y, Zhang YY, Li J. Effect of gpd box copy numbers in the gpdA promoter of Aspergillus nidulans on its transcription efficiency in Aspergillus niger. FEMS Microbiol Lett 2018; 365:5045313. [DOI: 10.1093/femsle/fny154] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 06/25/2018] [Indexed: 11/13/2022] Open
Affiliation(s)
- He Zhang
- College of Life Sciences, Northeast Agricultural University, No. 600 Changjiang Street Xiangfang District, Harbin 150030, China
| | - Jian nan Yan
- College of Life Sciences, Northeast Agricultural University, No. 600 Changjiang Street Xiangfang District, Harbin 150030, China
| | - Hui Zhang
- College of Life Sciences, Northeast Agricultural University, No. 600 Changjiang Street Xiangfang District, Harbin 150030, China
| | - Tian qi Liu
- College of Life Sciences, Northeast Agricultural University, No. 600 Changjiang Street Xiangfang District, Harbin 150030, China
| | - Yue Xu
- College of Life Sciences, Northeast Agricultural University, No. 600 Changjiang Street Xiangfang District, Harbin 150030, China
| | - Yuan yuan Zhang
- College of Life Sciences, Northeast Agricultural University, No. 600 Changjiang Street Xiangfang District, Harbin 150030, China
| | - Jie Li
- College of Life Sciences, Northeast Agricultural University, No. 600 Changjiang Street Xiangfang District, Harbin 150030, China
| |
Collapse
|
8
|
Han G, Shao Q, Li C, Zhao K, Jiang L, Fan J, Jiang H, Tao F. An efficient Agrobacterium-mediated transformation method for aflatoxin generation fungus Aspergillus flavus. J Microbiol 2018; 56:356-364. [DOI: 10.1007/s12275-018-7349-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 02/13/2018] [Accepted: 02/19/2018] [Indexed: 10/17/2022]
|
9
|
Oakley CE, Ahuja M, Sun WW, Entwistle R, Akashi T, Yaegashi J, Guo CJ, Cerqueira GC, Russo Wortman J, Wang CCC, Chiang YM, Oakley BR. Discovery of McrA, a master regulator of Aspergillus secondary metabolism. Mol Microbiol 2016; 103:347-365. [PMID: 27775185 DOI: 10.1111/mmi.13562] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/16/2016] [Indexed: 01/17/2023]
Abstract
Fungal secondary metabolites (SMs) are extremely important in medicine and agriculture, but regulation of their biosynthesis is incompletely understood. We have developed a genetic screen in Aspergillus nidulans for negative regulators of fungal SM gene clusters and we have used this screen to isolate mutations that upregulate transcription of the non-ribosomal peptide synthetase gene required for nidulanin A biosynthesis. Several of these mutations are allelic and we have identified the mutant gene by genome sequencing. The gene, which we designate mcrA, is conserved but uncharacterized, and it encodes a putative transcription factor. Metabolite profiles of mcrA deletant, mcrA overexpressing, and parental strains reveal that mcrA regulates at least ten SM gene clusters. Deletion of mcrA stimulates SM production even in strains carrying a deletion of the SM regulator laeA, and deletion of mcrA homologs in Aspergillus terreus and Penicillum canescens alters the secondary metabolite profile of these organisms. Deleting mcrA in a genetic dereplication strain has allowed us to discover two novel compounds as well as an antibiotic not known to be produced by A. nidulans. Deletion of mcrA upregulates transcription of hundreds of genes including many that are involved in secondary metabolism, while downregulating a smaller number of genes.
Collapse
Affiliation(s)
- C Elizabeth Oakley
- Department of Molecular Biosciences, University of Kansas, 1200 Sunnyside Avenue, Lawrence, Kansas, 66045, USA
| | - Manmeet Ahuja
- Department of Molecular Biosciences, University of Kansas, 1200 Sunnyside Avenue, Lawrence, Kansas, 66045, USA
| | - Wei-Wen Sun
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, California, 90089, USA
| | - Ruth Entwistle
- Department of Molecular Biosciences, University of Kansas, 1200 Sunnyside Avenue, Lawrence, Kansas, 66045, USA
| | - Tomohiro Akashi
- Division of OMICS analysis, Nagoya University Graduate School of Medicine, 65 Tsurumai, Nagoya, Aichi, 466-8550, Japan
| | - Junko Yaegashi
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, California, 90089, USA
| | - Chun-Jun Guo
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, California, 90089, USA
| | - Gustavo C Cerqueira
- Genome Sequencing and Analysis Program, Broad Institute of MIT and Harvard, 415 Main St, Cambridge, MA, 02142, USA
| | - Jennifer Russo Wortman
- Genome Sequencing and Analysis Program, Broad Institute of MIT and Harvard, 415 Main St, Cambridge, MA, 02142, USA
| | - Clay C C Wang
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, California, 90089, USA.,Department of Chemistry, Dornsife Colleges of Letters, Arts, and Sciences, University of Southern California, Los Angeles, California, 90089, USA
| | - Yi-Ming Chiang
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, California, 90089, USA.,Department of Pharmacy, Chia Nan University of Pharmacy and Science, Tainan City, Taiwan, 71710, Republic of China
| | - Berl R Oakley
- Department of Molecular Biosciences, University of Kansas, 1200 Sunnyside Avenue, Lawrence, Kansas, 66045, USA
| |
Collapse
|
10
|
Ying SH, Liu J, Chu XL, Xie XQ, Feng MG. The autophagy-related genes BbATG1 and BbATG8 have different functions in differentiation, stress resistance and virulence of mycopathogen Beauveria bassiana. Sci Rep 2016; 6:26376. [PMID: 27197558 PMCID: PMC4873834 DOI: 10.1038/srep26376] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 04/29/2016] [Indexed: 12/22/2022] Open
Abstract
Autophagy-related proteins play significantly different roles in eukaryotes. In the entomopathogenic fungus Beauveria bassiana, autophagy is associated with fungal growth and development. BbATG1 (a serine/threonine protein kinase) and BbATG8 (a ubiquitin-like protein) have similar roles in autophagy, but different roles in other processes. Disruption mutants of BbATG1 and BbATG8 had impaired conidial germination under starvation stress. The mutant ΔBbATG8 exhibited enhanced sensitivity to oxidative stress, while a ΔBbATG1 mutant did not. BbATG1 and BbATG8 showed different roles in spore differentiation. The blastospore yield was reduced by 70% and 92% in ΔBbATG1 and ΔBbATG8 mutants, respectively, and the double mutant had a reduction of 95%. Conidial yield was reduced by approximately 90% and 50% in ΔBbATG1 and ΔBbATG8 mutants, respectively. A double mutant had a reduction similar to ΔBbATG1. Additionally, both BbATG1 and BbATG8 affected the levels of conidial protein BbCP15p required for conidiation. The virulence of each autophagy-deficient mutant was considerably weakened as indicated in topical and intrahemocoel injection assays, and showed a greater reduction in topical infection. However, BbATG1 and BbATG8 had different effects on fungal virulence. Our data indicate that these autophagy-related proteins have different functions in fungal stress response, asexual development and virulence.
Collapse
Affiliation(s)
- Sheng-Hua Ying
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, People’s Republic of China
| | - Jing Liu
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, People’s Republic of China
| | - Xin-Ling Chu
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, People’s Republic of China
| | - Xue-Qin Xie
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, People’s Republic of China
| | - Ming-Guang Feng
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, People’s Republic of China
| |
Collapse
|
11
|
Su X, Schmitz G, Zhang M, Mackie RI, Cann IKO. Heterologous gene expression in filamentous fungi. ADVANCES IN APPLIED MICROBIOLOGY 2016; 81:1-61. [PMID: 22958526 DOI: 10.1016/b978-0-12-394382-8.00001-0] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Filamentous fungi are critical to production of many commercial enzymes and organic compounds. Fungal-based systems have several advantages over bacterial-based systems for protein production because high-level secretion of enzymes is a common trait of their decomposer lifestyle. Furthermore, in the large-scale production of recombinant proteins of eukaryotic origin, the filamentous fungi become the vehicle of choice due to critical processes shared in gene expression with other eukaryotic organisms. The complexity and relative dearth of understanding of the physiology of filamentous fungi, compared to bacteria, have hindered rapid development of these organisms as highly efficient factories for the production of heterologous proteins. In this review, we highlight several of the known benefits and challenges in using filamentous fungi (particularly Aspergillus spp., Trichoderma reesei, and Neurospora crassa) for the production of proteins, especially heterologous, nonfungal enzymes. We review various techniques commonly employed in recombinant protein production in the filamentous fungi, including transformation methods, selection of gene regulatory elements such as promoters, protein secretion factors such as the signal peptide, and optimization of coding sequence. We provide insights into current models of host genomic defenses such as repeat-induced point mutation and quelling. Furthermore, we examine the regulatory effects of transcript sequences, including introns and untranslated regions, pre-mRNA (messenger RNA) processing, transcript transport, and mRNA stability. We anticipate that this review will become a resource for researchers who aim at advancing the use of these fascinating organisms as protein production factories, for both academic and industrial purposes, and also for scientists with general interest in the biology of the filamentous fungi.
Collapse
Affiliation(s)
- Xiaoyun Su
- Energy Biosciences Institute, University of Illinois, Urbana, IL, USA; Institute for Genomic Biology, University of Illinois, Urbana, IL, USA; Equal contribution
| | | | | | | | | |
Collapse
|
12
|
Wunsch C, Mundt K, Li SM. Targeted production of secondary metabolites by coexpression of non-ribosomal peptide synthetase and prenyltransferase genes in Aspergillus. Appl Microbiol Biotechnol 2015; 99:4213-23. [DOI: 10.1007/s00253-015-6490-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2014] [Revised: 02/05/2015] [Accepted: 02/17/2015] [Indexed: 02/07/2023]
|
13
|
Huang X, Lu X, Li Y, Li X, Li JJ. Improving itaconic acid production through genetic engineering of an industrial Aspergillus terreus strain. Microb Cell Fact 2014; 13:119. [PMID: 25162789 PMCID: PMC4251695 DOI: 10.1186/s12934-014-0119-y] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 08/05/2014] [Indexed: 11/10/2022] Open
Abstract
Background Itaconic acid, which has been declared to be one of the most promising and flexible building blocks, is currently used as monomer or co-monomer in the polymer industry, and produced commercially by Aspergillus terreus. However, the production level of itaconic acid hasn’t been improved in the past 40 years, and mutagenesis is still the main strategy to improve itaconate productivity. The genetic engineering approach hasn’t been applied in industrial A. terreus strains to increase itaconic acid production. Results In this study, the genes closely related to itaconic acid production, including cadA, mfsA, mttA, ATEG_09969, gpdA, ATEG_01954, acoA, mt-pfkA and citA, were identified and overexpressed in an industrial A. terreus strain respectively. Overexpression of the genes cadA (cis-aconitate decarboxylase) and mfsA (Major Facilitator Superfamily Transporter) enhanced the itaconate production level by 9.4% and 5.1% in shake flasks respectively. Overexpression of other genes showed varied effects on itaconate production. The titers of other organic acids were affected by the introduced genes to different extent. Conclusions Itaconic acid production could be improved through genetic engineering of the industrially used A. terreus strain. We have identified some important genes such as cadA and mfsA, whose overexpression led to the increased itaconate productivity, and successfully developed a strategy to establish a highly efficient microbial cell factory for itaconate protuction. Our results will provide a guide for further enhancement of the itaconic acid production level through genetic engineering in future. Electronic supplementary material The online version of this article (doi:10.1186/s12934-014-0119-y) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
| | | | | | | | - Jian-Jun Li
- Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, No, 189 Songling Road, Qingdao 266101, China.
| |
Collapse
|
14
|
Qiu L, Wang JJ, Ying SH, Feng MG. Wee1 and Cdc25 control morphogenesis, virulence and multistress tolerance ofBeauveria bassianaby balancing cell cycle-required cyclin-dependent kinase 1 activity. Environ Microbiol 2014; 17:1119-33. [DOI: 10.1111/1462-2920.12530] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2014] [Revised: 05/31/2014] [Accepted: 05/31/2014] [Indexed: 01/08/2023]
Affiliation(s)
- Lei Qiu
- Institute of Microbiology; College of Life Sciences; Zhejiang University; Hangzhou Zhejiang 310058 China
| | - Juan-Juan Wang
- Institute of Microbiology; College of Life Sciences; Zhejiang University; Hangzhou Zhejiang 310058 China
| | - Sheng-Hua Ying
- Institute of Microbiology; College of Life Sciences; Zhejiang University; Hangzhou Zhejiang 310058 China
| | - Ming-Guang Feng
- Institute of Microbiology; College of Life Sciences; Zhejiang University; Hangzhou Zhejiang 310058 China
| |
Collapse
|
15
|
Flipphi M, Oestreicher N, Nicolas V, Guitton A, Vélot C. The Aspergillus nidulans acuL gene encodes a mitochondrial carrier required for the utilization of carbon sources that are metabolized via the TCA cycle. Fungal Genet Biol 2014; 68:9-22. [DOI: 10.1016/j.fgb.2014.04.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 04/24/2014] [Accepted: 04/29/2014] [Indexed: 10/25/2022]
|
16
|
Häkkinen M, Valkonen MJ, Westerholm-Parvinen A, Aro N, Arvas M, Vitikainen M, Penttilä M, Saloheimo M, Pakula TM. Screening of candidate regulators for cellulase and hemicellulase production in Trichoderma reesei and identification of a factor essential for cellulase production. BIOTECHNOLOGY FOR BIOFUELS 2014; 7:14. [PMID: 24472375 PMCID: PMC3922861 DOI: 10.1186/1754-6834-7-14] [Citation(s) in RCA: 169] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Accepted: 01/14/2014] [Indexed: 05/21/2023]
Abstract
BACKGROUND The soft rot ascomycetal fungus Trichoderma reesei is utilized for industrial production of secreted enzymes, especially lignocellulose degrading enzymes. T. reesei uses several different enzymes for the degradation of plant cell wall-derived material, including 9 characterized cellulases, 15 characterized hemicellulases and at least 42 genes predicted to encode cellulolytic or hemicellulolytic activities. Production of cellulases and hemicellulases is modulated by environmental and physiological conditions. Several regulators affecting the expression of cellulase and hemicellulase genes have been identified but more factors still unknown are believed to be present in the genome of T. reesei. RESULTS We have used transcriptional profiling data from T. reesei cultures in which cellulase/hemicellulase production was induced by the addition of different lignocellulose-derived materials to identify putative novel regulators for cellulase and hemicellulase genes. Based on this induction data, supplemented with other published genome-wide data on different protein production conditions, 28 candidate regulatory genes were selected for further studies and they were overexpressed in T. reesei. Overexpression of seven genes led to at least 1.5-fold increased production of cellulase and/or xylanase activity in the modified strains as compared to the parental strain. Deletion of gene 77513, here designated as ace3, was found to be detrimental for cellulase production and for the expression of several cellulase genes studied. This deletion also significantly reduced xylanase activity and expression of xylan-degrading enzyme genes. Furthermore, our data revealed the presence of co-regulated chromosomal regions containing carbohydrate-active enzyme genes and candidate regulatory genes. CONCLUSIONS Transcriptional profiling results from glycoside hydrolase induction experiments combined with a previous study of specific protein production conditions was shown to be an effective method for finding novel candidate regulatory genes affecting the production of cellulases and hemicellulases. Recombinant strains with improved cellulase and/or xylanase production properties were constructed, and a gene essential for cellulase gene expression was found. In addition, more evidence was gained on the chromatin level regional regulation of carbohydrate-active enzyme gene expression.
Collapse
Affiliation(s)
- Mari Häkkinen
- VTT Technical Research Centre of Finland, PO Box 1000 Tietotie 2, Espoo FI-02044, VTT, Finland
| | - Mari J Valkonen
- VTT Technical Research Centre of Finland, PO Box 1000 Tietotie 2, Espoo FI-02044, VTT, Finland
| | - Ann Westerholm-Parvinen
- VTT Technical Research Centre of Finland, PO Box 1000 Tietotie 2, Espoo FI-02044, VTT, Finland
| | - Nina Aro
- VTT Technical Research Centre of Finland, PO Box 1000 Tietotie 2, Espoo FI-02044, VTT, Finland
| | - Mikko Arvas
- VTT Technical Research Centre of Finland, PO Box 1000 Tietotie 2, Espoo FI-02044, VTT, Finland
| | - Marika Vitikainen
- VTT Technical Research Centre of Finland, PO Box 1000 Tietotie 2, Espoo FI-02044, VTT, Finland
| | - Merja Penttilä
- VTT Technical Research Centre of Finland, PO Box 1000 Tietotie 2, Espoo FI-02044, VTT, Finland
| | - Markku Saloheimo
- VTT Technical Research Centre of Finland, PO Box 1000 Tietotie 2, Espoo FI-02044, VTT, Finland
| | - Tiina M Pakula
- VTT Technical Research Centre of Finland, PO Box 1000 Tietotie 2, Espoo FI-02044, VTT, Finland
| |
Collapse
|
17
|
Chai R, Qiu C, Liu D, Qi Y, Gao Y, Shen J, Qiu L. β-Glucan synthase gene overexpression and β-glucans overproduction in Pleurotus ostreatus using promoter swapping. PLoS One 2013; 8:e61693. [PMID: 23637884 PMCID: PMC3634845 DOI: 10.1371/journal.pone.0061693] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Accepted: 03/13/2013] [Indexed: 11/19/2022] Open
Abstract
Mushroom β-glucans are potent immunological stimulators in medicine, but their productivities are very low. In this study, we successfully improved its production by promoter engineering in Pleurotus ostreatus. The promoter for β-1,3-glucan synthase gene (GLS) was replaced by the promoter of glyceraldehyde-3-phosphate dehydrogenase gene of Aspergillus nidulans. The homologous recombination fragment for swapping GLS promoter comprised five segments, which were fused by two rounds of combined touchdown PCR and overlap extension PCR (TD-OE PCR), and was introduced into P. ostreatus through PEG/CaCl2-mediated protoplast transformation. The transformants exhibited one to three fold higher transcription of GLS gene and produced 32% to 131% higher yield of β-glucans than the wild type. The polysaccharide yields had a significant positive correlation to the GLS gene expression. The infrared spectra of the polysaccharides all displayed the typical absorption peaks of β-glucans. This is the first report of successful swapping of promoters in filamentous fungi.
Collapse
Affiliation(s)
- Ran Chai
- College of Life Sciences, Henan Agricultural University, Zhengzhou, People's Republic of China
- Key Laboratory of Enzyme Engineering of Agricultural Microbiology, Ministry of Agriculture, Zhengzhou, People's Republic of China
| | - Cuiwei Qiu
- College of Life Sciences, Henan Agricultural University, Zhengzhou, People's Republic of China
- Key Laboratory of Enzyme Engineering of Agricultural Microbiology, Ministry of Agriculture, Zhengzhou, People's Republic of China
| | - Dongren Liu
- College of Life Sciences, Henan Agricultural University, Zhengzhou, People's Republic of China
- Key Laboratory of Enzyme Engineering of Agricultural Microbiology, Ministry of Agriculture, Zhengzhou, People's Republic of China
| | - Yuancheng Qi
- College of Life Sciences, Henan Agricultural University, Zhengzhou, People's Republic of China
- Key Laboratory of Enzyme Engineering of Agricultural Microbiology, Ministry of Agriculture, Zhengzhou, People's Republic of China
| | - Yuqian Gao
- College of Life Sciences, Henan Agricultural University, Zhengzhou, People's Republic of China
- Key Laboratory of Enzyme Engineering of Agricultural Microbiology, Ministry of Agriculture, Zhengzhou, People's Republic of China
| | - Jinwen Shen
- College of Life Sciences, Henan Agricultural University, Zhengzhou, People's Republic of China
- Key Laboratory of Enzyme Engineering of Agricultural Microbiology, Ministry of Agriculture, Zhengzhou, People's Republic of China
| | - Liyou Qiu
- College of Life Sciences, Henan Agricultural University, Zhengzhou, People's Republic of China
- Key Laboratory of Enzyme Engineering of Agricultural Microbiology, Ministry of Agriculture, Zhengzhou, People's Republic of China
- * E-mail:
| |
Collapse
|
18
|
Tani S, Tsuji A, Kunitake E, Sumitani JI, Kawaguchi T. Reversible impairment of the ku80 gene by a recyclable marker in Aspergillus aculeatus. AMB Express 2013; 3:4. [PMID: 23311774 PMCID: PMC3598690 DOI: 10.1186/2191-0855-3-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Accepted: 12/29/2012] [Indexed: 11/10/2022] Open
Abstract
Auxotrophic mutants of Aspergillus can be isolated in the presence of counter-selective compounds, but the process is laborious. We developed a method to enable reversible impairment of the ku80 gene (Aaku80) in the imperfect fungus Aspergillus aculeatus. Aaku80 was replaced with a selection marker, orotidine 5'-phosphate decarboxylase (pyrG), followed by excision of pyrG between direct repeats (DR) to yield the Aaku80 deletion mutant (MR12). The gene-targeting efficiency at the ornithine carbamoyltransferase (argB) locus was drastically elevated from 3% to 96% in MR12. The frequency of marker recycling depended on DR length. One uridine auxotroph was obtained from 3.3 × 105, 1.4 × 105, and 9.2 × 103 conidia from strains harboring 20-, 98-, and 495-bp DRs, respectively. Because these strains maintained the short DRs after 5 d of cultivation, we investigated whether Aaku80 function was disrupted by pyrG insertion with the 20-bp DR and restored after excision of pyrG. The Aaku80 disruption mutant (coku80) was bred by inserting pyrG sandwiched between 20-bp DRs into the second intron of Aaku80, followed by excision of pyrG between the DRs to yield the coku80rec strain. Analyses of homologous recombination frequency and methyl methanesulfonate sensitivity demonstrated that Aaku80 function was disrupted in coku80 but restored in coku80rec. Furthermore, pyrG was maintained in coku80 at least for ten generations. These data indicated that reversible impairment of ku80 in A. aculeatus is useful for functional genomics in cases where genetic segregation is not feasible.
Collapse
|
19
|
Punya J, Tachaleat A, Wattanachaisaereekul S, Haritakun R, Boonlarppradab C, Cheevadhanarak S. Functional expression of a foreign gene in Aspergillus oryzae producing new pyrone compounds. Fungal Genet Biol 2013; 50:55-62. [DOI: 10.1016/j.fgb.2012.10.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2012] [Revised: 10/15/2012] [Accepted: 10/22/2012] [Indexed: 12/17/2022]
|
20
|
Kunitake E, Tani S, Sumitani JI, Kawaguchi T. A novel transcriptional regulator, ClbR, controls the cellobiose- and cellulose-responsive induction of cellulase and xylanase genes regulated by two distinct signaling pathways in Aspergillus aculeatus. Appl Microbiol Biotechnol 2012; 97:2017-28. [DOI: 10.1007/s00253-012-4305-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Revised: 07/13/2012] [Accepted: 07/13/2012] [Indexed: 10/28/2022]
|
21
|
Ravanal MC, Rosa L, Polanco R, Eyzaguirre J, Espinosa Y, Levicán G, Chávez R, Vaca I. Glucose-induced production of a Penicillium purpurogenum xylanase by Aspergillus nidulans. MYCOSCIENCE 2012. [DOI: 10.1007/s10267-011-0144-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
22
|
Putative stress sensors WscA and WscB are involved in hypo-osmotic and acidic pH stress tolerance in Aspergillus nidulans. EUKARYOTIC CELL 2011; 10:1504-15. [PMID: 21926329 DOI: 10.1128/ec.05080-11] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Wsc proteins have been identified in fungi and are believed to be stress sensors in the cell wall integrity (CWI) signaling pathway. In this study, we characterized the sensor orthologs WscA and WscB in Aspergillus nidulans. Using hemagglutinin-tagged WscA and WscB, we showed both Wsc proteins to be N- and O-glycosylated and localized in the cell wall and membrane, implying that they are potential cell surface sensors. The wscA disruptant (ΔwscA) strain was characterized by reduced colony and conidia formation and a high frequency of swollen hyphae under hypo-osmotic conditions. The deficient phenotype of the ΔwscA strain was facilitated by acidification, but not by alkalization or antifungal agents. In contrast, osmotic stabilization restored the normal phenotype in the ΔwscA strain. A similar inhibition was observed in the wscB disruptant strain, but to a lesser extent. In addition, a double wscA and wscB disruptant (ΔwscA ΔwscB) strain was viable, but its growth was inhibited to a greater degree, indicating that the functions of the products of these genes are redundant. Transcription of α-1,3-glucan synthase genes (agsA and agsB) was significantly altered in the wscA disruptant strain, resulting in an increase in the amount of alkali-soluble cell wall glucan compared to that in the wild-type (wt) strain. An increase in mitogen-activated protein kinase (MpkA) phosphorylation was observed as a result of wsc disruption. Moreover, the transient transcriptional upregulation of the agsB gene via MpkA signaling was observed in the ΔwscA ΔwscB strain to the same degree as in the wt strain. These results indicate that A. nidulans Wsc proteins have a different sensing spectrum and downstream signaling pathway than those in the yeast Saccharomyces cerevisiae and that they play an important role in CWI under hypo-osmotic and acidic pH conditions.
Collapse
|
23
|
Cloning and heterologous expression of the extracellular alpha-galactosidase from Aspergillus fumigatus in Aspergillus sojae under the control of gpdA promoter. ACTA ACUST UNITED AC 2010. [DOI: 10.1016/j.molcatb.2009.09.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
24
|
Flaherty JE, Payne GA. Overexpression of aflR Leads to Upregulation of Pathway Gene Transcription and Increased Aflatoxin Production in Aspergillus flavus. Appl Environ Microbiol 2010; 63:3995-4000. [PMID: 16535712 PMCID: PMC1389268 DOI: 10.1128/aem.63.10.3995-4000.1997] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The aflatoxin biosynthetic pathway regulatory gene, aflR, encodes a putative 47-kDa protein containing a zinc cluster DNA binding motif. It is required for the transcription of all of the characterized aflatoxin pathway genes in both Aspergillus flavus and Aspergillus parasiticus. The objective of this study was to examine the effects of aflR overexpression on temporal gene expression, aflatoxin production, and nitrate inhibition of aflatoxin biosynthesis in A. flavus. An inducible expression construct was made by fusing the coding region of aflR to the promoter region of the A. flavus adh1 gene. This construct was transformed into A. flavus 656-2 (FGSC A1010), a strain mutated at the aflR locus. Strain 656-2 containing the adh1(p)::aflR construct had induced transcription of two early aflatoxin pathway genes, nor-1 and pksA, and produced wild-type concentrations of aflatoxin in a temporal pattern similar to that of wild-type strains of A. flavus. Strains 656-2 and 86-10 (FGSC A1009) an aflatoxigenic strain, were transformed with a construct containing the constitutive promoter gpdA driving aflR. Transformants of these strains constitutively expressed aflR, fas-1A, pksA, nor-1, and omtA but did not constitutively produce aflatoxin. Strain 86-10 containing the gpdA(p)::aflR construct produced 50 times more aflatoxin than 86-10, but the temporal pattern of aflatoxin production was the same as for 86-10, and aflatoxin production was also induced by sucrose. The addition of 10 g of nitrate per liter to sucrose low salts medium inhibited aflatoxin production by both strain 86-10 and a transformant of 86-10 containing the gpdA(p)::aflR construct, indicating that nitrate inhibition of aflatoxin biosynthesis does not occur solely at the level of aflR transcription. These studies show that constitutive overexpression of the pathway transcriptional regulatory gene aflR leads to higher transcript accumulation of pathway genes and increased aflatoxin production but that the initiation of aflatoxin biosynthesis is not solely regulated by the transcriptional activities of the biosynthetic pathway.
Collapse
|
25
|
Approaches for refining heterologous protein production in filamentous fungi. World J Microbiol Biotechnol 2009. [DOI: 10.1007/s11274-009-0128-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
26
|
Zhu T, Wang W, Yang X, Wang K, Cui Z. Construction of two gateway vectors for gene expression in fungi. Plasmid 2009; 62:128-33. [PMID: 19545587 DOI: 10.1016/j.plasmid.2009.06.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2009] [Revised: 06/12/2009] [Accepted: 06/16/2009] [Indexed: 10/20/2022]
Abstract
We report the construction of two Gateway fungal expression vectors pCBGW and pGWBF. The pCBGW was generated by introducing an expression cassette, which consists of a Gateway recombinant cassette (attR1-Cmr-ccdB-attR2) under the control of fungal promoter PgpdA and a terminator TtrpC, into the multiple cloning site of fungal vector pCB1004. The pGWBF is a binary vector, which was generated from the plant expression vector pGWB2 by replacing the CaMV35S promoter with PgpdA. The pGWBF can be transformed into fungi efficiently with Agrobacterium-mediated transformation. The applicability of two newly constructed vectors was tested by generating the destination vectors pGWBF-GFP and pCBGW-GFP and examining the expression of GFP gene in Trichoderma viride and Gibberella fujikuroi, respectively. Combining with the advantage of Gateway cloning technology, pCBGW and pGWBF will be useful in fungi for large-scale investigation of gene functions by constructing the interested gene destination/expression vectors in a high-throughput way.
Collapse
Affiliation(s)
- Tingheng Zhu
- Zhejiang University of Technology, Hangzhou, China
| | | | | | | | | |
Collapse
|
27
|
Production of the Aspergillus aculeatus endo-1,4-β-mannanase in A. niger. J Ind Microbiol Biotechnol 2009; 36:611-7. [DOI: 10.1007/s10295-009-0551-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2008] [Accepted: 02/16/2009] [Indexed: 10/21/2022]
|
28
|
Hofmann G, Diano A, Nielsen J. Recombinant bacterial hemoglobin alters metabolism of Aspergillus niger. Metab Eng 2009; 11:8-12. [DOI: 10.1016/j.ymben.2008.07.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2008] [Revised: 06/27/2008] [Accepted: 07/17/2008] [Indexed: 11/17/2022]
|
29
|
Wang L, Ridgway D, Gu T, Moo-Young M. KINETIC MODELING OF CELL GROWTH AND PRODUCT FORMATION IN SUBMERGED CULTURE OF RECOMBINANTASPERGILLUS NIGER. CHEM ENG COMMUN 2008. [DOI: 10.1080/00986440802483947] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
30
|
Brodhagen M, Tsitsigiannis DI, Hornung E, Goebel C, Feussner I, Keller NP. Reciprocal oxylipin-mediated cross-talk in the Aspergillus-seed pathosystem. Mol Microbiol 2007; 67:378-91. [DOI: 10.1111/j.1365-2958.2007.06045.x] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
|
31
|
Ni M, Yu JH. A novel regulator couples sporogenesis and trehalose biogenesis in Aspergillus nidulans. PLoS One 2007; 2:e970. [PMID: 17912349 PMCID: PMC1978537 DOI: 10.1371/journal.pone.0000970] [Citation(s) in RCA: 181] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2007] [Accepted: 09/09/2007] [Indexed: 12/28/2022] Open
Abstract
Trehalose is a compatible osmolyte produced by bacteria, fungi, insects and plants to protect the integrity of cells against various environmental stresses. Spores, the reproductive, survival and infection bodies of fungi require high amounts of trehalose for long-term survival. Here, via a gain-of-function genetic screen, we identify the novel regulator VosA that couples the formation of spores and focal trehalose biogenesis in the model fungus Aspergillus nidulans. The vosA gene is expressed specifically during the formation of both sexual and asexual spores (conidia). Levels of vosA mRNA and protein are high in both types of spore. The deletion of vosA results in the lack of trehalose in spores, a rapid loss of the cytoplasm, organelles and viability of spores, and a dramatic reduction in tolerance of conidia to heat and oxidative stress. Moreover, the absence of vosA causes uncontrolled activation of asexual development, whereas the enhanced expression of vosA blocks sporulation, suggesting that VosA also functions in negative-feedback regulation of sporogenesis. VosA localizes in the nucleus of mature conidia and its C-terminal region contains a potential transcription activation domain, indicating that it may function as a transcription factor primarily controlling the late process of sporulation including trehalose biogenesis. VosA is conserved in most fungi and may define a new fungus-specific transcription factor family.
Collapse
MESH Headings
- Aspergillus nidulans/metabolism
- Cloning, Molecular
- Gene Expression Regulation, Fungal
- Genes, Fungal
- Microscopy, Electron, Transmission
- Models, Biological
- Models, Genetic
- Protein Structure, Tertiary
- RNA, Fungal/metabolism
- RNA, Messenger/metabolism
- Spores, Fungal
- Trans-Activators/genetics
- Trans-Activators/physiology
- Transcriptional Activation
- Trehalose/chemistry
- Trehalose/metabolism
- Two-Hybrid System Techniques
Collapse
Affiliation(s)
- Min Ni
- Department of Bacteriology, University of Wisconsin, Madison, Wisconsin, United States of America
- Department of Genetics, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Jae-Hyuk Yu
- Department of Bacteriology, University of Wisconsin, Madison, Wisconsin, United States of America
- Department of Genetics, University of Wisconsin, Madison, Wisconsin, United States of America
| |
Collapse
|
32
|
Cao Y, Peng G, He Z, Wang Z, Yin Y, Xia Y. Transformation of Metarhizium anisopliae with benomyl resistance and green fluorescent protein genes provides a tag for genetically engineered strains. Biotechnol Lett 2007; 29:907-11. [PMID: 17310320 DOI: 10.1007/s10529-007-9332-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2006] [Revised: 01/18/2007] [Accepted: 01/22/2007] [Indexed: 11/24/2022]
Abstract
A plasmid, pBGFP, carrying green fluorescent protein (gfp) and benomyl-resistance genes was constructed and transformed into Metarhizium anisopliae. The transformants grew normally and GFP fluorescence was detected. No change was found in virulence for the transformants. Fluorescence was detected in hyphae from the haemolymph of the infected locust, and the benomyl-resistance was maintained. Results suggested that the two markers provided a useful tool for screening and monitoring the engineered strains even after infection.
Collapse
Affiliation(s)
- Yueqing Cao
- Genetic Engineering Research Center, Institute of Bioengineering, Chongqing University, Chongqing, PR China
| | | | | | | | | | | |
Collapse
|
33
|
Barhoom S, Sharon A. Bcl-2 proteins link programmed cell death with growth and morphogenetic adaptations in the fungal plant pathogen Colletotrichum gloeosporioides. Fungal Genet Biol 2007; 44:32-43. [PMID: 16950636 DOI: 10.1016/j.fgb.2006.06.007] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2006] [Revised: 06/05/2006] [Accepted: 06/13/2006] [Indexed: 10/24/2022]
Abstract
Proteins belonging to the Bcl-2 family regulate apoptosis in mammals by controlling mitochondria efflux of cytochrome c and other apoptosis-related proteins. Homologues of human Bcl-2 proteins are found in different metazoan organisms where they play a similar role, while they seem to be absent in plants and fungi. Nonetheless, Bcl-2 protein members can induce or prevent yeast cell death, suggesting that enough functional conservation exists between apoptotic machineries of mammals and fungi. Here we show that induction or prevention of apoptosis by Bcl-2 proteins in the fungal plant pathogen Colletotrichum gloeosporioides is tightly linked with growth and morphogenetic adaptation that occur throughout the entire fungal life cycle. Isolates expressing the pro-apoptotic Bax protein underwent cell death with apoptotic characteristics, and showed alterations in conidial germination that are associated with pathogenic and non-pathogenic life styles. Isolates expressing the anti-apoptotic Bcl-2 protein had prolonged longevity, were protected from Bax-induced cell death, and exhibited enhanced stress resistance. These isolates also had enhanced mycelium and conidia production, and were hyper virulent to host plants. Our findings show that apoptotic-associated machinery regulates morphogenetic switches, which are critical for proper responses and adaptation fungi to different environments.
Collapse
Affiliation(s)
- Sima Barhoom
- Department of Plant Sciences, Tel Aviv University, Tel Aviv, Israel
| | | |
Collapse
|
34
|
Flipphi M, Robellet X, Dequier E, Leschelle X, Felenbok B, Vélot C. Functional analysis of alcS, a gene of the alc cluster in Aspergillus nidulans. Fungal Genet Biol 2006; 43:247-60. [PMID: 16531087 DOI: 10.1016/j.fgb.2005.12.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2005] [Revised: 12/08/2005] [Accepted: 12/19/2005] [Indexed: 11/26/2022]
Abstract
The ethanol utilization pathway (alc system) of Aspergillus nidulans requires two structural genes, alcA and aldA, which encode the two enzymes (alcohol dehydrogenase and aldehyde dehydrogenase, respectively) allowing conversion of ethanol into acetate via acetyldehyde, and a regulatory gene, alcR, encoding the pathway-specific autoregulated transcriptional activator. The alcR and alcA genes are clustered with three other genes that are also positively regulated by alcR, although they are dispensable for growth on ethanol. In this study, we characterized alcS, the most abundantly transcribed of these three genes. alcS is strictly co-regulated with alcA, and encodes a 262-amino acid protein. Sequence comparison with protein databases detected a putative conserved domain that is characteristic of the novel GPR1/FUN34/YaaH membrane protein family. It was shown that the AlcS protein is located in the plasma membrane. Deletion or overexpression of alcS did not result in any obvious phenotype. In particular, AlcS does not appear to be essential for the transport of ethanol, acetaldehyde or acetate. Basic Local Alignment Search Tool analysis against the A. nidulans genome led to the identification of two novel ethanol- and ethylacetate-induced genes encoding other members of the GPR1/FUN34/YaaH family, AN5226 and AN8390.
Collapse
MESH Headings
- Alcohol Dehydrogenase/genetics
- Aldehyde Dehydrogenase/genetics
- Amino Acid Motifs
- Amino Acid Sequence
- Aspergillus nidulans/genetics
- Aspergillus nidulans/metabolism
- Base Sequence
- Blotting, Northern
- Cell Membrane/chemistry
- Conserved Sequence
- DNA, Fungal/chemistry
- DNA, Fungal/genetics
- Fungal Proteins/chemistry
- Fungal Proteins/genetics
- Gene Deletion
- Gene Dosage
- Gene Expression Regulation, Fungal
- Genes, Fungal
- Introns/genetics
- Membrane Proteins/chemistry
- Membrane Proteins/genetics
- Molecular Sequence Data
- Multigene Family
- Mutagenesis, Insertional
- Open Reading Frames
- RNA, Fungal/analysis
- RNA, Messenger/analysis
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
- Transcription, Genetic
Collapse
Affiliation(s)
- Michel Flipphi
- Institut de Génétique et Microbiologie, CNRS Unité Mixte de Recherche 8621, Université Paris-Sud XI, Centre Scientifique d'Orsay, Bâtiment 360, F-91405 Orsay Cedex, France
| | | | | | | | | | | |
Collapse
|
35
|
Weenink XO, Punt PJ, van den Hondel CAMJJ, Ram AFJ. A new method for screening and isolation of hypersecretion mutants in Aspergillus niger. Appl Microbiol Biotechnol 2006; 69:711-7. [PMID: 16021486 DOI: 10.1007/s00253-005-0013-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2005] [Revised: 04/21/2005] [Accepted: 04/23/2005] [Indexed: 10/25/2022]
Abstract
Although filamentous fungi have a unique property of secreting a large amount of homologous extracellular proteins, the use of filamentous fungi as hosts for the production of heterologous proteins is limited because of the low production levels that are generally reached. Here, we report a general screening method for the isolation of mutants with increased protein production levels. The screening method makes use of an Aspergillus niger strain that lacks the two major amylolytic enzymes, glucoamylase (GlaA) and acid amylase (AamA). The double-mutant strain grows poorly on starch and its growth is restored after reintroducing the catalytic part of the glucoamylase gene (GlaA512). We show that the fusion of a heterologous protein, a laccase from Pleurotus ostreatus (Pox2), to the catalytic part of glucoamylase (GlaA512-Pox2) severely hampers efficient production of the glucoamylase protein, resulting in a slow-growth phenotype on starch. Laccase-hypersecreting mutants were obtained by isolating mutants that displayed improved growth on starch plates. The mutant with the highest growth rate on starch displayed the highest laccase activity, indicating that increased glucoamylase protein levels are correlated with higher laccase production levels. In principle, our method can be applied to any low-produced heterologous protein that is secreted as a fusion with the glucoamylase protein.
Collapse
Affiliation(s)
- Xavier O Weenink
- Clusius Laboratory, Fungal Genetics Research Group, Institute of Biology, Leiden University, Wassenaarseweg 64, 2333 AL, Leiden, The Netherlands
| | | | | | | |
Collapse
|
36
|
Tsitsigiannis DI, Bok JW, Andes D, Nielsen KF, Frisvad JC, Keller NP. Aspergillus cyclooxygenase-like enzymes are associated with prostaglandin production and virulence. Infect Immun 2005; 73:4548-59. [PMID: 16040966 PMCID: PMC1201276 DOI: 10.1128/iai.73.8.4548-4559.2005] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Oxylipins comprise a family of oxygenated fatty acid-derived signaling molecules that initiate critical biological activities in animals, plants, and fungi. Mammalian oxylipins, including the prostaglandins (PGs), mediate many immune and inflammation responses in animals. PG production by pathogenic microbes is theorized to play a role in pathogenesis. We have genetically characterized three Aspergillus genes, ppoA, ppoB, and ppoC, encoding fatty acid oxygenases similar in sequence to specific mammalian prostaglandin synthases, the cyclooxygenases. Enzyme-linked immunosorbent assay analysis showed that production of PG species is decreased in both Aspergillus nidulans and A. fumigatus ppo mutants, implicating Ppo activity in generating PGs. The A. fumigatus triple-ppo-silenced mutant was hypervirulent in the invasive pulmonary aspergillosis murine model system and showed increased tolerance to H(2)O(2) stress relative to that of the wild type. We propose that Ppo products, PG, and/or other oxylipins may serve as activators of mammalian immune responses contributing to enhanced resistance to opportunistic fungi and as factors that modulate fungal development contributing to resistance to host defenses.
Collapse
|
37
|
McDonald T, Brown D, Keller NP, Hammond TM. RNA silencing of mycotoxin production in Aspergillus and Fusarium species. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2005; 18:539-45. [PMID: 15986923 DOI: 10.1094/mpmi-18-0539] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Mycotoxins are natural fungal products that are defined by their harmful effects on humans and animals. Aflatoxin contamination of maize by Aspergillus species and trichothecene contamination of small grains by Fusarium species are two of the most severe mycotoxin problems in the United States. We are investigating RNA silencing in an effort to identify novel ways to control mycotoxin contamination of crops. Transformation of two Aspergilli (A. flavus and A. parasiticus) and a Fusarium (F. graminearum) with inverted repeat transgenes (IRT) containing sequences of mycotoxin-specific regulatory genes suppressed mycotoxin production in all three plant-pathogenic fungi. This atoxigenic phenotype was stable during infection on corn and wheat, and importantly, F. graminearum IRT strains were less virulent on wheat than were wild type. The IRT did not alter physiological characteristics of the fungi, such as spore production and growth rate on solid media. These results indicate that RNA silencing exists in Aspergillus and Fusarium plant pathogens and suggest that RNA silencing technology may be a useful tool for eliminating mycotoxin contamination of agricultural products.
Collapse
Affiliation(s)
- Tami McDonald
- Department of Plant Pathology, University of Wisconsin, Madison, USA
| | | | | | | |
Collapse
|
38
|
Pachlinger R, Mitterbauer R, Adam G, Strauss J. Metabolically independent and accurately adjustable Aspergillus sp. expression system. Appl Environ Microbiol 2005; 71:672-8. [PMID: 15691916 PMCID: PMC546773 DOI: 10.1128/aem.71.2.672-678.2005] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Filamentous fungi are well-established expression hosts often used to produce extracellular proteins of use in the food and pharmaceutical industries. The expression systems presently used in Aspergillus species rely on either strong constitutive promoters, e.g., that for glyceraldehyde-3-phosphate dehydrogenase, or inducible systems derived from metabolic pathways, e.g., glaA (glucoamylase) or alc (alcohol dehydrogenase). We describe for Aspergillus nidulans and Aspergillus niger a novel expression system that utilizes the transcriptional activation of the human estrogen receptor by estrogenic substances. The system functions independently from metabolic signals and therefore can be used with low-cost, complex media. A combination of positive and negative regulatory elements in the promoter drives the expression of a reporter gene, yielding a linear dose response to the inducer. The off status is completely tight, yet the system responds within minutes to induction and reaches a level of expression of up to 15% of total cell protein after 8 h. Both Aspergillus species are very sensitive to estrogenic substances, and low-cost inducers function in the picomolar concentration range, at which estrogenic substances also can be found in the environment. Given this high sensitivity to estrogens, Aspergillus cells carrying estrogen-responsive units could be used to detect xenoestrogens in food or in the environment.
Collapse
Affiliation(s)
- Robert Pachlinger
- Institut für Angewandte Genetik und Zellbiologie, BOKU-University of Natural Resources and Applied Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
| | | | | | | |
Collapse
|
39
|
Hammond TM, Keller NP. RNA silencing in Aspergillus nidulans is independent of RNA-dependent RNA polymerases. Genetics 2004; 169:607-17. [PMID: 15545645 PMCID: PMC1449118 DOI: 10.1534/genetics.104.035964] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The versatility of RNA-dependent RNA polymerases (RDRPs) in eukaryotic gene silencing is perhaps best illustrated in the kingdom Fungi. Biochemical and genetic studies of Schizosaccharomyces pombe and Neurospora crassa show that these types of enzymes are involved in a number of fundamental gene-silencing processes, including heterochromatin regulation and RNA silencing in S. pombe and meiotic silencing and RNA silencing in N. crassa. Here we show that Aspergillus nidulans, another model fungus, does not require an RDRP for inverted repeat transgene (IRT)-induced RNA silencing. However, RDRP requirements may vary within the Aspergillus genus as genomic analysis indicates that A. nidulans, but not A. fumigatus or A. oryzae, has lost a QDE-1 ortholog, an RDRP associated with RNA silencing in N. crassa. We also provide evidence suggesting that 5' --> 3' transitive RNA silencing is not a significant aspect of A. nidulans IRT-RNA silencing. These results indicate a lack of conserved kingdom-wide requirements for RDRPs in fungal RNA silencing.
Collapse
Affiliation(s)
- T M Hammond
- Department of Plant Pathology, University of Wisconsin, Madison, Wisconsin 53706, USA
| | | |
Collapse
|
40
|
Nelson G, Kozlova-Zwinderman O, Collis AJ, Knight MR, Fincham JRS, Stanger CP, Renwick A, Hessing JGM, Punt PJ, van den Hondel CAMJJ, Read ND. Calcium measurement in living filamentous fungi expressing codon-optimized aequorin. Mol Microbiol 2004; 52:1437-50. [PMID: 15165245 DOI: 10.1111/j.1365-2958.2004.04066.x] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Calcium signalling is little understood in filamentous fungi largely because easy and routine methods for calcium measurement in living hyphae have previously been unavailable. We have developed the recombinant aequorin method for this purpose. High levels of aequorin expression were obtained in Neurospora crassa, Aspergillus niger and Aspergillus awamori by codon optimization of the aequorin gene. Three external stimuli (mechanical perturbation, hypo-osmotic shock and high external calcium) were found transiently to increase [Ca(2+)](c). Each of the calcium signatures associated with these physico-chemical treatments was unique, suggesting the involvement of three distinct calcium-mediated signal transduction pathways. The fungal calcium channel blocker KP4 inhibited the [Ca(2+)](c) responses to hypo-osmotic shock and high external calcium, but not to mechanical perturbation. The divalent cation chelator BAPTA inhibited [Ca(2+)](c) responses to mechanical perturbation and hypo-osmotic shock. The calcium agonists A23187 and cyclopiazonic acid increased [Ca(2+)](c) levels.
Collapse
Affiliation(s)
- G Nelson
- Fungal Cell Biology Group, Institute of Cell and Molecular Biology, University of Edinburgh, Rutherford Building, Edinburgh EH9 3JH, UK
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
41
|
Molecular cloning of the promoter region of the glyceraldehyde-3-phosphate dehydrogenase gene that contributes to the construction of a new transformation system in Coriolus versicolor. MYCOSCIENCE 2004. [DOI: 10.1007/s10267-003-0164-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
42
|
Tsitsigiannis DI, Zarnowski R, Keller NP. The lipid body protein, PpoA, coordinates sexual and asexual sporulation in Aspergillus nidulans. J Biol Chem 2003; 279:11344-53. [PMID: 14699095 DOI: 10.1074/jbc.m310840200] [Citation(s) in RCA: 153] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The coexistence of sexual and asexual reproductive cycles within the same individual is a striking phenomenon in numerous fungi. In the fungus Aspergillus nidulans (teleomorph: Emericella nidulans) endogenous oxylipins, called psi factor, serve as hormone-like signals that modulate the timing and balance between sexual and asexual spore development. Here, we report the identification of A. nidulans ppoA, encoding a putative fatty acid dioxygenase, involved in the biosynthesis of the linoleic acid derived oxylipin psiBalpha. PpoA is required for balancing anamorph and teleomorph development. Deletion of ppoA significantly reduced the level of psiBalpha and increased the ratio of asexual to sexual spore numbers 4-fold. In contrast, forced expression of ppoA resulted in elevated levels of psiBalpha and decreased the ratio of asexual to sexual spore numbers 6-fold. ppoA expression is mediated by two developmental regulators, VeA and the COP9 signalosome, such that ppoA transcript levels are correlated with the initiation of asexual and sexual fruiting body formation. PpoA localizes in lipid bodies in these tissues. These data support an important role for oxylipins in integrating mitotic and meiotic spore development.
Collapse
|
43
|
Shim WB, Flaherty JE, Woloshuk CP. Comparison of fumonisin B1 biosynthesis in maize germ and degermed kernels by Fusarium verticillioides. J Food Prot 2003; 66:2116-22. [PMID: 14627291 DOI: 10.4315/0362-028x-66.11.2116] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Fusarium verticillioides produces a group of mycotoxins known as fumonisins in maize kernels. Fumonisins are associated with a variety of mycotoxicoses in humans and animals; thus, their presence in food is a considerable safety issue. This study addressed fumonisin B1 (FB1) production in two components of the maize kernel, namely the germ tissues and the degermed kernel. Growth of F. verticillioides was similar in colonized germ tissue and degermed kernels, but FB1 production was at least five times higher in degermed maize kernels than in germ tissue. Expression of the fumonisin polyketide synthase gene, FUM1, as measured by beta-glucuronidase (GUS) and Northern blot analysis, followed the same pattern as FB1 production. Also correlated to FB1 was a concomitant drop in pH of the colonized degermed kernels. A time course experiment showed that degermed kernels inoculated with F. verticillioides became acidified over time (from pH 6.4 to 4.7 after 10 days of incubation), whereas colonized germ tissue became alkaline over the same period (from pH 6.5 to 8.5). Because conditions of acidic pH are conducive to FB1 production and alkaline pH is repressive, the observed correlation between the acidification of degermed kernels and the increase in FB1 provides one explanation for the observed differences in FB1 levels.
Collapse
Affiliation(s)
- Won-Bo Shim
- Department of Botany and Plant Pathology, 915 W State Street, Purdue University, West Lafayette, Indiana 47907, USA
| | | | | |
Collapse
|
44
|
Plüddemann A, Van Zyl WH. Evaluation of Aspergillus niger as host for virus-like particle production, using the hepatitis B surface antigen as a model. Curr Genet 2003; 43:439-46. [PMID: 12802503 DOI: 10.1007/s00294-003-0409-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2003] [Revised: 05/06/2003] [Accepted: 05/08/2003] [Indexed: 01/04/2023]
Abstract
The filamentous fungus Aspergillus niger was transformed with the hepatitis B virus S gene encoding the major viral envelope protein under control of the constitutive A. nidulans glyceraldehyde-3-phosphate dehydrogenase ( gpdA) promoter. Approximately seven copies of the expression cassette were integrated on the genome, resulting in high-level transcription of the S gene. Production of the 24-kDa S protein and a 48-kDa S protein dimer in the membrane-associated protein fraction of the recombinant A. niger strain was shown through Western analysis. Electron microscopy of partially purified recombinant S protein revealed the formation of spherical pseudoviral particles with a diameter of 22 nm. The production level of hepatitis B pseudoviral particles was estimated to be 0.4 mg/l culture, which compares favourably with the reported levels initially obtained in yeast, indicating the potential of the Aspergillus expression system as an alternative, cost-effective vaccine production system.
Collapse
Affiliation(s)
- Annette Plüddemann
- Department of Microbiology, University of Stellenbosch, Private Bag X1, 7602, Matieland, South Africa.
| | | |
Collapse
|
45
|
Conesa A, van De Velde F, van Rantwijk F, Sheldon RA, van Den Hondel CA, Punt PJ. Expression of the Caldariomyces fumago chloroperoxidase in Aspergillus niger and characterization of the recombinant enzyme. J Biol Chem 2001; 276:17635-40. [PMID: 11278701 DOI: 10.1074/jbc.m010571200] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Caldariomyces fumago chloroperoxidase was successfully expressed in Aspergillus niger. The recombinant enzyme was produced in the culture medium as an active protein and could be purified by a three-step purification procedure. The catalytic behavior of recombinant chloroperoxidase (rCPO) was studied and compared with that of native CPO. The specific chlorination activity (47 units/nmol) of rCPO and its pH optimum (pH 2.75) were very similar to those of native CPO. rCPO catalyzes the oxidation of various substrates in comparable yields and selectivities to native CPO. Indole was oxidized to 2-oxindole with 99% selectivity and thioanisole to the corresponding R-sulfoxide (enantiomeric excess >98%). Incorporation of (18)O from labeled H(2)18O(2) into the oxidized products was 100% in both cases.
Collapse
Affiliation(s)
- A Conesa
- Department of Applied Microbiology and Gene Technology, TNO Nutrition and Food Research Institute, Utrechtseweg 48, 3704 HE Zeist, The Netherlands
| | | | | | | | | | | |
Collapse
|
46
|
Flipphi M, Mathieu M, Cirpus I, Panozzo C, Felenbok B. Regulation of the aldehyde dehydrogenase gene (aldA) and its role in the control of the coinducer level necessary for induction of the ethanol utilization pathway in Aspergillus nidulans. J Biol Chem 2001; 276:6950-8. [PMID: 11102439 DOI: 10.1074/jbc.m005769200] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Expression of the structural genes for alcohol and aldehyde dehydrogenase, alcA and aldA, respectively, enables the fungus Aspergillus nidulans to grow on ethanol. The pathway-specific transcriptional activator AlcR mediates the induction of ethanol catabolism in the presence of a coinducing compound. Ethanol catabolism is further subject to negative control mediated by the general carbon catabolite repressor CreA. Here we show that, in contrast to alcA and alcR, the aldA gene is not directly subject to CreA repression. A single cis-acting element mediates AlcR activation of aldA. Furthermore, we show that the induction of the alc gene system is linked to in situ aldehyde dehydrogenase activity. In aldA loss-of-function mutants, the alc genes are induced under normally noninducing conditions. This pseudo-constitutive expression correlates with the nature of the mutations, suggesting that this feature is caused by an intracellular accumulation of a coinducing compound. Conversely, constitutive overexpression of aldA results in suppression of induction in the presence of ethanol. This shows unambiguously that acetaldehyde is the sole physiological inducer of ethanol catabolism. We hypothesize that the intracellular acetaldehyde concentration is the critical factor governing the induction of the alc gene system.
Collapse
Affiliation(s)
- M Flipphi
- Institut de Génétique et Microbiologie, CNRS UMR 8621, Université Paris-Sud XI, Centre Universitaire d'Orsay, Bâtiment 409, F-91405 Orsay Cedex, France
| | | | | | | | | |
Collapse
|
47
|
Current progress in the analysis of transcriptional regulation in the industrially valuable microorganismAspergillus oryzae. BIOTECHNOL BIOPROC E 2000. [DOI: 10.1007/bf02942182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
48
|
Conesa A, van den Hondel CA, Punt PJ. Studies on the production of fungal peroxidases in Aspergillus niger. Appl Environ Microbiol 2000; 66:3016-23. [PMID: 10877800 PMCID: PMC92105 DOI: 10.1128/aem.66.7.3016-3023.2000] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
To get insight into the limiting factors existing for the efficient production of fungal peroxidase in filamentous fungi, the expression of the Phanerochaete chrysosporium lignin peroxidase H8 (lipA) and manganese peroxidase (MnP) H4 (mnp1) genes in Aspergillus niger has been studied. For this purpose, a protease-deficient A. niger strain and different expression cassettes have been used. Northern blotting experiments indicated high steady-state mRNA levels for the recombinant genes. Manganese peroxidase was secreted into the culture medium as an active protein. The recombinant protein showed specific activity and a spectrum profile similar to those of the native enzyme, was correctly processed at its N terminus, and had a slightly lower mobility on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Recombinant MnP production could be increased up to 100 mg/liter upon hemoglobin supplementation of the culture medium. Lignin peroxidase was also secreted into the extracellular medium, although the protein was not active, presumably due to incorrect processing of the secreted enzyme. Expression of the lipA and mnp1 genes fused to the A. niger glucoamylase gene did not result in improved production yields.
Collapse
Affiliation(s)
- A Conesa
- Department of Molecular Genetics and Gene Technology, TNO Nutrition and Food Research Institute, 3704 HE Zeist, The Netherlands
| | | | | |
Collapse
|
49
|
Wiebe MG, Robson GD, Shuster J, Trinci AP. Growth-rate-independent production of recombinant glucoamylase by Fusarium venenatum JeRS 325. Biotechnol Bioeng 2000; 68:245-51. [PMID: 10745192 DOI: 10.1002/(sici)1097-0290(20000505)68:3<245::aid-bit2>3.0.co;2-f] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Most recombinant proteins generated in filamentous fungi are produced in fed-batch cultures, in which specific growth rate normally decreases progressively with time. Because of this, such cultures are more suited to the production of products that are produced efficiently at low-growth rates (e.g., penicillin) than to products which are produced more efficiently at high-growth rates (e. g., glucoamylase). Fusarium venenatum A3/5 has been transformed (JeRS 325) to produce Aspergillus niger glucoamylase (GAM) under the control of the Fusarium oxysporum trypsin-like protease promoter. No glucoamylase was detected in the culture supernatant during exponential growth of F. venenatum JeRS 325 in batch culture. In glucose-limited chemostat cultures, GAM concentration increased with decrease in dilution rate, but the specific production rate of GAM (g GAM [g biomass](-1) h(-1)) remained approximately constant over the dilution-rate range 0.05 h to 0.19 h(-1), i.e., the recombinant protein was produced in a growth-rate-independent manner. The specific production rate decreased at dilution rates of 0.04 h(-1) and below. Specific production rates of 5.8 mg and 4.0 mg GAM [g biomass](-1) h(-1) were observed in glucose-limited chemostat cultures in the presence and absence of 1 g mycological peptone L(-1). Compared to production in batch culture, and for the same final volume of medium, there was no increase in glucoamylase production when cultures were grown in fed-batch culture. The results suggested that a chemostat operated at a slow dilution rate would be the most productive culture system for enzyme production under this trypsin-like promoter.
Collapse
Affiliation(s)
- M G Wiebe
- School of Biological Sciences, 1.800 Stopford Building, University of Manchester, Manchester, M13 9PT, United Kingdom.
| | | | | | | |
Collapse
|
50
|
Deane EE, Whipps JM, Lynch JM, Peberdy JF. Transformation of Trichoderma reesei with a constitutively expressed heterologous fungal chitinase gene. Enzyme Microb Technol 1999. [DOI: 10.1016/s0141-0229(98)00155-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|