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Hou X, Liu L, Xu D, Lai D, Zhou L. Involvement of LaeA and Velvet Proteins in Regulating the Production of Mycotoxins and Other Fungal Secondary Metabolites. J Fungi (Basel) 2024; 10:561. [PMID: 39194887 DOI: 10.3390/jof10080561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2024] [Revised: 07/30/2024] [Accepted: 08/06/2024] [Indexed: 08/29/2024] Open
Abstract
Fungi are rich sources of secondary metabolites of agrochemical, pharmaceutical, and food importance, such as mycotoxins, antibiotics, and antitumor agents. Secondary metabolites play vital roles in fungal pathogenesis, growth and development, oxidative status modulation, and adaptation/resistance to various environmental stresses. LaeA contains an S-adenosylmethionine binding site and displays methyltransferase activity. The members of velvet proteins include VeA, VelB, VelC, VelD and VosA for each member with a velvet domain. LaeA and velvet proteins can form multimeric complexes such as VosA-VelB and VelB-VeA-LaeA. They belong to global regulators and are mainly impacted by light. One of their most important functions is to regulate gene expressions that are responsible for secondary metabolite biosynthesis. The aim of this mini-review is to represent the newest cognition of the biosynthetic regulation of mycotoxins and other fungal secondary metabolites by LaeA and velvet proteins. In most cases, LaeA and velvet proteins positively regulate production of fungal secondary metabolites. The regulated fungal species mainly belong to the toxigenic fungi from the genera of Alternaria, Aspergillus, Botrytis, Fusarium, Magnaporthe, Monascus, and Penicillium for the production of mycotoxins. We can control secondary metabolite production to inhibit the production of harmful mycotoxins while promoting the production of useful metabolites by global regulation of LaeA and velvet proteins in fungi. Furthermore, the regulation by LaeA and velvet proteins should be a practical strategy in activating silent biosynthetic gene clusters (BGCs) in fungi to obtain previously undiscovered metabolites.
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Affiliation(s)
- Xuwen Hou
- MOA Key Lab of Pest Monitoring and Green Management, Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Liyao Liu
- MOA Key Lab of Pest Monitoring and Green Management, Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Dan Xu
- MOA Key Lab of Pest Monitoring and Green Management, Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Daowan Lai
- MOA Key Lab of Pest Monitoring and Green Management, Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Ligang Zhou
- MOA Key Lab of Pest Monitoring and Green Management, Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing 100193, China
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Zhang X, Yang Y, Wang L, Qin Y. Histone H2B lysine 122 and lysine 130, as the putative targets of Penicillium oxalicum LaeA, play important roles in asexual development, expression of secondary metabolite gene clusters, and extracellular glycoside hydrolase synthesis. World J Microbiol Biotechnol 2024; 40:179. [PMID: 38668807 DOI: 10.1007/s11274-024-03978-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 04/03/2024] [Indexed: 05/01/2024]
Abstract
Core histones in the nucleosome are subject to a wide variety of posttranslational modifications (PTMs), such as methylation, phosphorylation, ubiquitylation, and acetylation, all of which are crucial in shaping the structure of the chromatin and the expression of the target genes. A putative histone methyltransferase LaeA/Lae1, which is conserved in numerous filamentous fungi, functions as a global regulator of fungal growth, virulence, secondary metabolite formation, and the production of extracellular glycoside hydrolases (GHs). LaeA's direct histone targets, however, were not yet recognized. Previous research has shown that LaeA interacts with core histone H2B. Using S-adenosyl-L-methionine (SAM) as a methyl group donor and recombinant human histone H2B as the substrate, it was found that Penicillium oxalicum LaeA can transfer the methyl groups to the C-terminal lysine (K) 108 and K116 residues in vitro. The H2BK108 and H2BK116 sites on recombinant histone correspond to P. oxalicum H2BK122 and H2BK130, respectively. H2BK122A and H2BK130A, two mutants with histone H2B K122 or K130 mutation to alanine (A), were constructed in P. oxalicum. The mutants H2BK122A and H2BK130A demonstrated altered asexual development and decreased extracellular GH production, consistent with the findings of the laeA gene deletion strain (ΔlaeA). The transcriptome data showed that when compared to wild-type (WT) of P. oxalicum, 38 of the 47 differentially expressed (fold change ≥ 2, FDR ≤ 0.05) genes that encode extracellular GHs showed the same expression pattern in the three mutants ΔlaeA, H2BK122A, and H2BK130A. The four secondary metabolic gene clusters that considerably decreased expression in ΔlaeA also significantly decreased in H2BK122A or H2BK130A. The chromatin of promotor regions of the key cellulolytic genes cel7A/cbh1 and cel7B/eg1 compacted in the ΔlaeA, H2BK122A, and H2BK130A mutants, according to the results of chromatin accessibility real-time PCR (CHART-PCR). The chromatin accessibility index dropped. The histone binding pocket of the LaeA-methyltransf_23 domain is compatible with particular histone H2B peptides, providing appropriate electrostatic and steric compatibility to stabilize these peptides, according to molecular docking. The findings of the study demonstrate that H2BK122 and H2BK130, which are histone targets of P. oxalicum LaeA in vitro, are crucial for fungal conidiation, the expression of gene clusters encoding secondary metabolites, and the production of extracellular GHs.
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Affiliation(s)
- Xiujun Zhang
- National Glycoengineering Research Center, Shandong University, Qingdao, China
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
- School of Biological Science and Technology, University of Jinan, Jinan, China
| | - Yuhong Yang
- School of Biological Science and Technology, University of Jinan, Jinan, China
| | - Lushan Wang
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
| | - Yuqi Qin
- National Glycoengineering Research Center, Shandong University, Qingdao, China.
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China.
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3
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Liu Z, Ma K, Zhang X, Song X, Qin Y. Different Putative Methyltransferases Have Different Effects on the Expression Patterns of Cellulolytic Genes. J Fungi (Basel) 2023; 9:1118. [PMID: 37998923 PMCID: PMC10671955 DOI: 10.3390/jof9111118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 11/07/2023] [Accepted: 11/16/2023] [Indexed: 11/25/2023] Open
Abstract
Putative methyltranferase LaeA and LaeA-like proteins, conserved in many filamentous fungi, regulate fungal growth, development, virulence, the biosynthesis of secondary metabolites, and the production of cellulolytic enzymes. Penicillium oxaliucm is a typical fungus that produces cellulolytic enzymes. In this study, we reported the biological function of eight putative methyltransferases (PoMtr23C/D/E/F/G/H and PoMtr25A/B) containing a methyltransf_23 or methyltransf_25 domain, with a focus on their roles in the production of cellulolytic enzymes. In P. oxalicum, various methyltransferase genes displayed different transcriptional levels. The genes Pomtr23C and Pomtr25A exhibited high transcriptional levels, while Pomtr23D/E/F/G/H and Pomtr25B were transcribed constantly at low levels. The gene deletion mutants (Δmtr23C/D/E/F/G/H and Δmtr25A/B) were constructed. Various mutants have different patterns in cellulolytic enzyme production. Compared to the WT, the largest increase in filter paper activity (FPA, indicating total cellulase activity) was observed in the Δmtr23G mutant, the only mutant with a cellulolytic halo surrounding the colony. Three mutants (Δmtr23C/D and Δmtr25A) also showed increased cellulolytic enzyme production. The Δmtr23E and Δmtr25B mutants displayed decreased FPA activity, while the Δmtr23F and Δmtr23H mutants displayed similar patterns of cellulolytic enzyme production compared with the WT. The assay of transcriptional levels of cellobiohydrolase gene Pocbh1 and β-1,4-endoglucanase Poeg1 supported that higher cellulolytic gene transcription resulted in higher production of cellulolytic enzymes, and vice versa. The transcriptional levels of two transcription factors, activator XlnR and repressor CreA, were measured. The high transcription level of the PoxlnR gene in the Δmtr23D mutant should be one reason for the increased transcription of its cellulolytic enzyme gene. Both XlnR and CreA transcriptional levels increased in the Δmtr23G mutant, but the former showed a more significant increase than the latter, indicating that the activation effect predominated. The PoMtr25A is localized in the nucleus. The catalytic subunit SNF2 of the SWI/SNF chromatin-remodeling complex was found as one of the interacting proteins of PoMtr25A via tandem affinity purification coupled with mass spectrometry. PoMtr25A may affect not only the transcription of repressor CreA but also by recruiting SWI/SNF complexes that affect chromatin structure, thereby regulating the transcription of target genes.
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Affiliation(s)
- Zhongjiao Liu
- National Glycoengineering Research Center, Shandong University, Qingdao 266237, China; (Z.L.); (K.M.); (X.Z.); (X.S.)
| | - Kexuan Ma
- National Glycoengineering Research Center, Shandong University, Qingdao 266237, China; (Z.L.); (K.M.); (X.Z.); (X.S.)
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Xiujun Zhang
- National Glycoengineering Research Center, Shandong University, Qingdao 266237, China; (Z.L.); (K.M.); (X.Z.); (X.S.)
- School of Biological Science and Technology, University of Jinan, Jinan 250024, China
| | - Xin Song
- National Glycoengineering Research Center, Shandong University, Qingdao 266237, China; (Z.L.); (K.M.); (X.Z.); (X.S.)
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Yuqi Qin
- National Glycoengineering Research Center, Shandong University, Qingdao 266237, China; (Z.L.); (K.M.); (X.Z.); (X.S.)
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
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Ran Y, Yang Q, Zeng J, Li F, Cao Y, Xu Q, Qiao D, Xu H, Cao Y. Potential xylose transporters regulated by CreA improved lipid yield and furfural tolerance in oleaginous yeast Saitozyma podzolica zwy-2-3. BIORESOURCE TECHNOLOGY 2023; 386:129413. [PMID: 37390935 DOI: 10.1016/j.biortech.2023.129413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 06/26/2023] [Accepted: 06/27/2023] [Indexed: 07/02/2023]
Abstract
Lignocellulose's hydrolysate, a significant renewable source, contains xylose and furfural, making it challenging for industrial production of oleaginous yeast. On xylose fermentation with furfural treatment, OE::DN7263 and OE::DN7661 increased lipid yield and furfural tolerance versus WT, while, which of OE::CreA were decreased owing to CreA regulating DN7263 and DN7661 negatively. OE::CreA generated reactive oxygen species (ROS) causing oxidative damage. OE::DN7263, OE::DN7661, and ΔCreA reduced furfural via NADH; while ΔCreA produced less ROS and OE::DN7263, and OE::DN7661 scavenged ROS quickly, minimizing oxidative damage. Overall, CreA knockout increased DN7263 and DN7661 expression to facilitate xylose assimilation, enhancing NADH generation and ROS clearance. Finally, with mixed sugar fermentation, ΔCreA and OE::DN7263's biomass and lipid yield rose without furfural addition, while that of ΔCreA remained higher than WT after furfural treatment. These findings revealed how oleaginous yeast zwy-2-3 resisted furfural stress and indicated ΔCreA and OE::DN7263 might develop into robust industrial chassis strains.
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Affiliation(s)
- Yulu Ran
- Microbiology and Metabolic Engineering Key Laboratory of Sichuan Province, College of Life Science, Sichuan University, Chengdu, Sichuan Province 610065, PR China
| | - Qingzhuoma Yang
- Microbiology and Metabolic Engineering Key Laboratory of Sichuan Province, College of Life Science, Sichuan University, Chengdu, Sichuan Province 610065, PR China
| | - Jie Zeng
- Microbiology and Metabolic Engineering Key Laboratory of Sichuan Province, College of Life Science, Sichuan University, Chengdu, Sichuan Province 610065, PR China
| | - Fazhi Li
- Microbiology and Metabolic Engineering Key Laboratory of Sichuan Province, College of Life Science, Sichuan University, Chengdu, Sichuan Province 610065, PR China
| | - Yu Cao
- Microbiology and Metabolic Engineering Key Laboratory of Sichuan Province, College of Life Science, Sichuan University, Chengdu, Sichuan Province 610065, PR China
| | - Qingrui Xu
- Microbiology and Metabolic Engineering Key Laboratory of Sichuan Province, College of Life Science, Sichuan University, Chengdu, Sichuan Province 610065, PR China
| | - Dairong Qiao
- Microbiology and Metabolic Engineering Key Laboratory of Sichuan Province, College of Life Science, Sichuan University, Chengdu, Sichuan Province 610065, PR China
| | - Hui Xu
- Microbiology and Metabolic Engineering Key Laboratory of Sichuan Province, College of Life Science, Sichuan University, Chengdu, Sichuan Province 610065, PR China.
| | - Yi Cao
- Microbiology and Metabolic Engineering Key Laboratory of Sichuan Province, College of Life Science, Sichuan University, Chengdu, Sichuan Province 610065, PR China.
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Marcano Y, Montanares M, Gil-Durán C, González K, Levicán G, Vaca I, Chávez R. Pr laeA Affects the Production of Roquefortine C, Mycophenolic Acid, and Andrastin A in Penicillium roqueforti, but It Has Little Impact on Asexual Development. J Fungi (Basel) 2023; 9:954. [PMID: 37888210 PMCID: PMC10607316 DOI: 10.3390/jof9100954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 09/14/2023] [Accepted: 09/20/2023] [Indexed: 10/28/2023] Open
Abstract
The regulation of fungal specialized metabolism is a complex process involving various regulators. Among these regulators, LaeA, a methyltransferase protein originally discovered in Aspergillus spp., plays a crucial role. Although the role of LaeA in specialized metabolism has been studied in different fungi, its function in Penicillium roqueforti remains unknown. In this study, we employed CRISPR-Cas9 technology to disrupt the laeA gene in P. roqueforti (PrlaeA) aiming to investigate its impact on the production of the specialized metabolites roquefortine C, mycophenolic acid, and andrastin A, as well as on asexual development, because they are processes that occur in the same temporal stages within the physiology of the fungus. Our results demonstrate a substantial reduction in the production of the three metabolites upon disruption of PrlaeA, suggesting a positive regulatory role of LaeA in their biosynthesis. These findings were further supported by qRT-PCR analysis, which revealed significant downregulation in the expression of genes associated with the biosynthetic gene clusters (BGCs) responsible for producing roquefortine C, mycophenolic acid, and andrastin A in the ΔPrlaeA strains compared with the wild-type P. roqueforti. Regarding asexual development, the disruption of PrlaeA led to a slight decrease in colony growth rate, while conidiation and conidial germination remained unaffected. Taken together, our results suggest that LaeA positively regulates the expression of the analyzed BGCs and the production of their corresponding metabolites in P. roqueforti, but it has little impact on asexual development.
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Affiliation(s)
- Yudethzi Marcano
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile (USACH), Santiago 9170022, Chile; (Y.M.); (C.G.-D.); (K.G.); (G.L.)
| | - Mariana Montanares
- Departamento de Química, Facultad de Ciencias, Universidad de Chile, Santiago 7800003, Chile;
| | - Carlos Gil-Durán
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile (USACH), Santiago 9170022, Chile; (Y.M.); (C.G.-D.); (K.G.); (G.L.)
| | - Kathia González
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile (USACH), Santiago 9170022, Chile; (Y.M.); (C.G.-D.); (K.G.); (G.L.)
| | - Gloria Levicán
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile (USACH), Santiago 9170022, Chile; (Y.M.); (C.G.-D.); (K.G.); (G.L.)
| | - Inmaculada Vaca
- Departamento de Química, Facultad de Ciencias, Universidad de Chile, Santiago 7800003, Chile;
| | - Renato Chávez
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile (USACH), Santiago 9170022, Chile; (Y.M.); (C.G.-D.); (K.G.); (G.L.)
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Zhang Y, Wang X, Ran Y, Zhang KQ, Li GH. AfLaeA, a Global Regulator of Mycelial Growth, Chlamydospore Production, Pathogenicity, Secondary Metabolism, and Energy Metabolism in the Nematode-Trapping Fungus Arthrobotrys flagrans. Microbiol Spectr 2023; 11:e0018623. [PMID: 37358432 PMCID: PMC10434191 DOI: 10.1128/spectrum.00186-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 05/15/2023] [Indexed: 06/27/2023] Open
Abstract
Arthrobotrys flagrans (Duddingtonia flagrans) is a typical nematode-trapping fungus which has been used for nematode biocontrol. The global regulator LaeA is widely distributed in filamentous fungi and plays a crucial role in secondary metabolism and development in addition to pathogenicity in fungal pathogens. In this study, the chromosome-level genome of A. flagrans CBS 565.50 was sequenced and homologous sequences of LaeA were identified in A. flagrans. A. flagrans LaeA (AfLaeA) knockout resulted in slower hyphal growth and a smoother hyphal surface. Importantly, deletion of AfLaeA resulted in the absence of chlamydospores and attenuated glycogen and lipid accumulation in hyphae. Similarly, disruption of the AfLaeA gene led to fewer traps and electron-dense bodies, lower protease activity, and a delay in capturing nematodes. The AfLaeA gene had a large effect on the secondary metabolism of A. flagrans, and both the deletion and overexpression of AfLaeA could yield new compounds, whereas some compounds were lost due to the absence of the AfLaeA. Protein-protein interactions between AfLaeA and another eight proteins were detected. Furthermore, transcriptome data analysis showed that 17.77% and 35.51% of the genes were influenced by the AfLaeA gene on days 3 and 7, respectively. AfLaeA gene deletion resulted in the higher expression level of the artA gene cluster, and multiple differentially expressed genes involved in glycogen and lipid synthesis and metabolism showed opposite expression patterns in wild-type and ΔAfLaeA strains. In summary, our results provide novel insights into the functions of AfLaeA in mycelial growth, chlamydospore production, pathogenicity, secondary metabolism, and energy metabolism in A. flagrans. IMPORTANCE The regulation of biological functions, such as the secondary metabolism, development, and pathogenicity of LaeA, has been reported in multiple fungi. But to date, no study on LaeA in nematode-trapping fungi has been reported. Moreover, it has not been investigated whether or not LaeA is involved in energy metabolism and chlamydospore formation has not been investigated. Especially in the formation mechanism of chlamydospores, several transcription factors and signaling pathways are involved in the production of chlamydospores, but the mechanism of chlamydospore formation from an epigenetic perspective has not been revealed. Concurrently, an understanding of protein-protein interactions will provide a broader perspective on the regulatory mechanism of AfLaeA in A. flagrans. This finding is critical for understanding the regulatory role of AfLaeA in the biocontrol fungus A. flagrans and establishes a foundation for developing high-efficiency nematode biocontrol agents.
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Affiliation(s)
- Yu Zhang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming, China
| | - Xin Wang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming, China
| | - Yuan Ran
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming, China
| | - Ke-Qin Zhang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming, China
| | - Guo-Hong Li
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming, China
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Recent Advances in Chitin Biosynthesis Associated with the Morphology and Secondary Metabolite Synthesis of Filamentous Fungi in Submerged Fermentation. J Fungi (Basel) 2023; 9:jof9020205. [PMID: 36836319 PMCID: PMC9967639 DOI: 10.3390/jof9020205] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 02/01/2023] [Accepted: 02/02/2023] [Indexed: 02/08/2023] Open
Abstract
Metabolites produced by filamentous fungi are used extensively in the food and drug industries. With the development of the morphological engineering of filamentous fungi, numerous biotechnologies have been applied to alter the morphology of fungal mycelia and enhance the yields and productivity of target metabolites during submerged fermentation. Disruption of chitin biosynthesis can modify the cell growth and mycelial morphology of filamentous fungi and regulate the biosynthesis of metabolites during submerged fermentation. In this review, we present a comprehensive coverage of the categories and structures of the enzyme chitin synthase, chitin biosynthetic pathways, and the association between chitin biosynthesis and cell growth and metabolism in filamentous fungi. Through this review, we hope to increase awareness of the metabolic engineering of filamentous fungal morphology, provide insights into the molecular mechanisms of morphological control via chitin biosynthesis, and describe strategies for the application of morphological engineering to enhance the production of target metabolites in filamentous fungi during submerged fermentation.
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Yang K, Tian J, Keller NP. Post-translational modifications drive secondary metabolite biosynthesis in Aspergillus: a review. Environ Microbiol 2022; 24:2857-2881. [PMID: 35645150 PMCID: PMC9545273 DOI: 10.1111/1462-2920.16034] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Revised: 04/23/2022] [Accepted: 04/26/2022] [Indexed: 12/26/2022]
Abstract
Post‐translational modifications (PTMs) are important for protein function and regulate multiple cellular processes and secondary metabolites (SMs) in fungi. Aspergillus species belong to a genus renown for an abundance of bioactive secondary metabolites, many important as toxins, pharmaceuticals and in industrial production. The genes required for secondary metabolites are typically co‐localized in biosynthetic gene clusters (BGCs), which often localize in heterochromatic regions of genome and are ‘turned off’ under laboratory condition. Efforts have been made to ‘turn on’ these BGCs by genetic manipulation of histone modifications, which could convert the heterochromatic structure to euchromatin. Additionally, non‐histone PTMs also play critical roles in the regulation of secondary metabolism. In this review, we collate the known roles of epigenetic and PTMs on Aspergillus SM production. We also summarize the proteomics approaches and bioinformatics tools for PTM identification and prediction and provide future perspectives on the emerging roles of PTM on regulation of SM biosynthesis in Aspergillus and other fungi.
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Affiliation(s)
- Kunlong Yang
- School of Life Science, Jiangsu Normal University, Xuzhou, 221116, Jiangsu Province, People's Republic of China.,Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, Wisconsin, 53705, USA
| | - Jun Tian
- School of Life Science, Jiangsu Normal University, Xuzhou, 221116, Jiangsu Province, People's Republic of China
| | - Nancy P Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, Wisconsin, 53705, USA
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Xu G, Guo H, Yan M, Jia Z, Li Z, Chen M, Bao X. An actin‐like protein
Po
ARP9
involves in the regulation of development and cellulase and amylase expression in
Penicillium oxalicum. J Appl Microbiol 2022; 132:2894-2905. [DOI: 10.1111/jam.15466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 12/28/2021] [Accepted: 01/23/2022] [Indexed: 12/01/2022]
Affiliation(s)
- Gen Xu
- State Key Laboratory of Biobased Material and Green Papermaking, School of bioengineering, Shandong Provincial Key Laboratory of Microbial Engineering Qilu University of Technology Shandong Academy of Sciences Jinan P. R. China
| | - Hao Guo
- State Key Laboratory of Biobased Material and Green Papermaking, School of bioengineering, Shandong Provincial Key Laboratory of Microbial Engineering Qilu University of Technology Shandong Academy of Sciences Jinan P. R. China
| | - Mengdi Yan
- State Key Laboratory of Biobased Material and Green Papermaking, School of bioengineering, Shandong Provincial Key Laboratory of Microbial Engineering Qilu University of Technology Shandong Academy of Sciences Jinan P. R. China
| | - Zhilei Jia
- State Key Laboratory of Biobased Material and Green Papermaking, School of bioengineering, Shandong Provincial Key Laboratory of Microbial Engineering Qilu University of Technology Shandong Academy of Sciences Jinan P. R. China
| | - Zhonghai Li
- State Key Laboratory of Biobased Material and Green Papermaking, School of bioengineering, Shandong Provincial Key Laboratory of Microbial Engineering Qilu University of Technology Shandong Academy of Sciences Jinan P. R. China
| | - Mei Chen
- State Key Laboratory of Biobased Material and Green Papermaking, School of bioengineering, Shandong Provincial Key Laboratory of Microbial Engineering Qilu University of Technology Shandong Academy of Sciences Jinan P. R. China
| | - Xiaoming Bao
- State Key Laboratory of Biobased Material and Green Papermaking, School of bioengineering, Shandong Provincial Key Laboratory of Microbial Engineering Qilu University of Technology Shandong Academy of Sciences Jinan P. R. China
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Zhang X, Hu Y, Liu G, Liu M, Li Z, Zhao J, Song X, Zhong Y, Qu Y, Wang L, Qin Y. The complex Tup1-Cyc8 bridges transcription factor ClrB and putative histone methyltransferase LaeA to activate the expression of cellulolytic genes. Mol Microbiol 2022; 117:1002-1022. [PMID: 35072962 DOI: 10.1111/mmi.14885] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 01/18/2022] [Accepted: 01/20/2022] [Indexed: 11/28/2022]
Abstract
The degradation of lignocellulosic biomass by cellulolytic enzymes is involved in the global carbon cycle. The hydrolysis of lignocellulosic biomass into fermentable sugars is potential as excellent industrial resource to produce a variety of chemical products. The production of cellulolytic enzymes is regulated mainly at the transcriptional level in filamentous fungi. Transcription factor ClrB and the putative histone methyltransferase LaeA, are both necessary for the expression of cellulolytic genes. However, the mechanism by which transcription factors and methyltransferase coordinately regulate cellulolytic genes is still unknown. Here, we reveal a transcriptional regulatory mechanism involving Penicillium oxalicum transcription factor ClrB (PoClrB), complex Tup1-Cyc8, and putative histone methyltransferase LaeA (PoLaeA). As the transcription factor, PoClrB binds the targeted promoters of cellulolytic genes, recruits PoTup1-Cyc8 complex via direct interaction with PoTup1. PoTup1 interacts with PoCyc8 to form the coactivator complex PoTup1-Cyc8. Then, PoTup1 recruits putative histone methyltransferase PoLaeA to modify the chromatin structure of the upstream region of cellulolytic genes, thereby facilitating the binding of transcription machinery to activating the corresponding cellulolytic gene expression. Our results contribute to a better understanding of complex transcriptional regulation mechanisms of cellulolytic genes and will be valuable for lignocellulosic biorefining.
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Affiliation(s)
- Xiujun Zhang
- National Glycoengineering Research Center, Shandong University, Qingdao, China.,State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China.,School of Biological Science and Technology, University of Jinan, Jinan, China
| | - Yueyan Hu
- National Glycoengineering Research Center, Shandong University, Qingdao, China.,State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
| | - Guodong Liu
- National Glycoengineering Research Center, Shandong University, Qingdao, China.,State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
| | - Meng Liu
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
| | - Zhonghai Li
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China.,State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, Jinan, China
| | - Jian Zhao
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
| | - Xin Song
- National Glycoengineering Research Center, Shandong University, Qingdao, China.,State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
| | - Yaohua Zhong
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
| | - Yinbo Qu
- National Glycoengineering Research Center, Shandong University, Qingdao, China.,State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
| | - Lushan Wang
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
| | - Yuqi Qin
- National Glycoengineering Research Center, Shandong University, Qingdao, China.,State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
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11
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Zhao K, Liu Z, Li M, Hu Y, Yang L, Song X, Qin Y. Drafting Penicillium oxalicum calcineurin-CrzA pathway by combining the analysis of phenotype, transcriptome, and endogenous protein-protein interactions. Fungal Genet Biol 2021; 158:103652. [PMID: 34920105 DOI: 10.1016/j.fgb.2021.103652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 11/17/2021] [Accepted: 12/08/2021] [Indexed: 11/04/2022]
Abstract
Fungi sense environmental signals and coordinate growth, development, and metabolism accordingly. Calcium-calmodulin-calcineurin signaling is a conserved cascade pathway in fungi. One of the most important downstream targets of this pathway is the transcription factor Crz1/CrzA, which plays an essential role in various cellular processes. The putative collaborators of Penicillium oxalicum CrzA (PoCrzA) were found, through tandem affinity purification followed by mass spectrometric analysis (TAP-MS). A total of 50 protein-protein interaction collaborators of PoCrzA were observed. Among them, some collaborators, such as the catalytic subunit of calcineurin (Cna1, calcineurin A), the regulatory catalytic subunit of calcineurin (Cnb1, calcineurin B), and a 14-3-3 protein Bmh1, which were previously reported in yeast, were identified. Some putative collaborators, including two karyopherins (exportin Los1 and importin Srp1), two kinases (Fus3 and Slt2p), and a general transcriptional corepressor (Cyc8), were also found. The CrzA deletion mutant ΔPocrzA exhibited slow hyphal growth, impaired conidiogenesis, and reduced extracellular cellulase synthesis. Phenotype and transcriptome analysis showed that PoCrzA regulated fungal development in a Flbs-BrlA-dependent manner and participated in cellulase synthesis by modulating cellulolytic gene expression. On the basis of the results of TAP-MS, transcriptome, and phenotypic analysis in P. oxalicum, our study was the first to draft the calcineurin-CrzA pathway in cellulolytic fungi.
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Affiliation(s)
- Kaili Zhao
- National Glycoengineering Research Center, Shandong University, No. 72 Binhai Road, Qingdao 266237, China.
| | - Zhongjiao Liu
- National Glycoengineering Research Center, Shandong University, No. 72 Binhai Road, Qingdao 266237, China.
| | - Mengxue Li
- National Glycoengineering Research Center, Shandong University, No. 72 Binhai Road, Qingdao 266237, China.
| | - Yueyan Hu
- National Glycoengineering Research Center, Shandong University, No. 72 Binhai Road, Qingdao 266237, China; State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, No. 72 Binhai Road, Qingdao 266237, China.
| | - Ling Yang
- Vocational Education College, Dezhou University, Dezhou 253023, China.
| | - Xin Song
- National Glycoengineering Research Center, Shandong University, No. 72 Binhai Road, Qingdao 266237, China; State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, No. 72 Binhai Road, Qingdao 266237, China.
| | - Yuqi Qin
- National Glycoengineering Research Center, Shandong University, No. 72 Binhai Road, Qingdao 266237, China; State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, No. 72 Binhai Road, Qingdao 266237, China.
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12
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Zhang T, Mai RM, Fang QQ, Ou JF, Mo LX, Tian D, Li CX, Gu LS, Luo XM, Feng JX, Zhao S. Regulatory function of the novel transcription factor CxrC in Penicillium oxalicum. Mol Microbiol 2021; 116:1512-1532. [PMID: 34797006 DOI: 10.1111/mmi.14843] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Revised: 10/24/2021] [Accepted: 11/08/2021] [Indexed: 12/31/2022]
Abstract
Numerous transcription factors (TFs) in ascomycete fungi play crucial roles in cellular processes; however, how most of them function is poorly understood. Here, we identified and characterized a novel TF, CxrC (POX01387), acting downstream of the key TF CxrA, which is essential for plant-biomass-degrading-enzyme (PBDE) production in Penicillium oxalicum. Deletion of cxrC in P. oxalicum significantly affected the production of PBDEs, as well as mycelial growth and conidiospore production. CxrA directly repressed the expression of cxrC after about 12 hr following switch to Avicel culture. CxrC bound the promoters of major PBDE genes and genes involved in conidiospore development. CxrC was found to bind the TSSGTYR core sequence (S: C and G; Y: T and C; R: G and A) of the important cellulase genes cbh1 and eg1. Both N- and C-terminal peptides of CxrC and the CxrC phosphorylation were found to mediate its homodimerization. The conserved motif LPSVRSLLTP (65-74) in CxrC was found to be required for regulating cellulase production. This study reveals novel mechanisms of TF-mediated regulation of the expression of PBDE genes and genes involved in cellular processes in an ascomycete fungus.
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Affiliation(s)
- Ting Zhang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Research Center for Microbial and Enzyme Engineering Technology, College of Life Science and Technology, Guangxi University, Nanning, People's Republic of China
| | - Rong-Ming Mai
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Research Center for Microbial and Enzyme Engineering Technology, College of Life Science and Technology, Guangxi University, Nanning, People's Republic of China
| | - Qi-Qi Fang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Research Center for Microbial and Enzyme Engineering Technology, College of Life Science and Technology, Guangxi University, Nanning, People's Republic of China
| | - Jian-Feng Ou
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Research Center for Microbial and Enzyme Engineering Technology, College of Life Science and Technology, Guangxi University, Nanning, People's Republic of China
| | - Li-Xiang Mo
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Research Center for Microbial and Enzyme Engineering Technology, College of Life Science and Technology, Guangxi University, Nanning, People's Republic of China
| | - Di Tian
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Research Center for Microbial and Enzyme Engineering Technology, College of Life Science and Technology, Guangxi University, Nanning, People's Republic of China
| | - Cheng-Xi Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Research Center for Microbial and Enzyme Engineering Technology, College of Life Science and Technology, Guangxi University, Nanning, People's Republic of China
| | - Li-Sha Gu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Research Center for Microbial and Enzyme Engineering Technology, College of Life Science and Technology, Guangxi University, Nanning, People's Republic of China
| | - Xue-Mei Luo
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Research Center for Microbial and Enzyme Engineering Technology, College of Life Science and Technology, Guangxi University, Nanning, People's Republic of China
| | - Jia-Xun Feng
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Research Center for Microbial and Enzyme Engineering Technology, College of Life Science and Technology, Guangxi University, Nanning, People's Republic of China
| | - Shuai Zhao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Research Center for Microbial and Enzyme Engineering Technology, College of Life Science and Technology, Guangxi University, Nanning, People's Republic of China
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13
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Maor U, Barda O, Sadhasivam S, Bi Y, Zakin V, Prusky DB, Sionov E. Host Factors Modulating Ochratoxin A Biosynthesis during Fruit Colonization by Aspergillus carbonarius. J Fungi (Basel) 2020; 7:10. [PMID: 33379151 PMCID: PMC7823970 DOI: 10.3390/jof7010010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 12/21/2020] [Accepted: 12/24/2020] [Indexed: 11/16/2022] Open
Abstract
Aspergillus carbonarius is a strong and consistent ochratoxin A (OTA) producer and considered to be the main source of this toxic metabolite in grapes and grape products such as wine, grape juice and dried vine fruit. OTA is produced under certain growth conditions and its accumulation is affected by several environmental factors, such as growth phase, substrate, temperature, water activity and pH. In this study, we examined the impact of fruit host factors on regulation and accumulation of OTA in colonized grape berries, and assessed in vitro the impact of those factors on the transcriptional levels of the key genes and global regulators contributing to fungal colonization and mycotoxin synthesis. We found that limited sugar content, low pH levels and high malic acid concentrations activated OTA biosynthesis by A. carbonarius, both in synthetic media and during fruit colonization, through modulation of global regulator of secondary metabolism, laeA and OTA gene cluster expression. These findings indicate that fruit host factors may have a significant impact on the capability of A. carbonarius to produce and accumulate OTA in grapes.
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Affiliation(s)
- Uriel Maor
- Institute of Postharvest and Food Sciences, The Volcani Center, Agricultural Research Organization, Rishon LeZion 7528809, Israel; (U.M.); (O.B.); (S.S.); (V.Z.); (D.B.P.)
- Institute of Biochemistry, Food Science and Nutrition, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 7610001, Israel
| | - Omer Barda
- Institute of Postharvest and Food Sciences, The Volcani Center, Agricultural Research Organization, Rishon LeZion 7528809, Israel; (U.M.); (O.B.); (S.S.); (V.Z.); (D.B.P.)
| | - Sudharsan Sadhasivam
- Institute of Postharvest and Food Sciences, The Volcani Center, Agricultural Research Organization, Rishon LeZion 7528809, Israel; (U.M.); (O.B.); (S.S.); (V.Z.); (D.B.P.)
| | - Yang Bi
- College of Food Science and Engineering, Gansu Agricultural University, Lanzhou 730070, China;
| | - Varda Zakin
- Institute of Postharvest and Food Sciences, The Volcani Center, Agricultural Research Organization, Rishon LeZion 7528809, Israel; (U.M.); (O.B.); (S.S.); (V.Z.); (D.B.P.)
| | - Dov B. Prusky
- Institute of Postharvest and Food Sciences, The Volcani Center, Agricultural Research Organization, Rishon LeZion 7528809, Israel; (U.M.); (O.B.); (S.S.); (V.Z.); (D.B.P.)
- College of Food Science and Engineering, Gansu Agricultural University, Lanzhou 730070, China;
| | - Edward Sionov
- Institute of Postharvest and Food Sciences, The Volcani Center, Agricultural Research Organization, Rishon LeZion 7528809, Israel; (U.M.); (O.B.); (S.S.); (V.Z.); (D.B.P.)
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14
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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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15
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Zhang X, Li M, Zhu Y, Yang L, Li Y, Qu J, Wang L, Zhao J, Qu Y, Qin Y. Penicillium oxalicum putative methyltransferase Mtr23B has similarities and differences with LaeA in regulating conidium development and glycoside hydrolase gene expression. Fungal Genet Biol 2020; 143:103445. [PMID: 32822857 DOI: 10.1016/j.fgb.2020.103445] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 08/07/2020] [Accepted: 08/12/2020] [Indexed: 11/18/2022]
Abstract
Putative methyltranferase LaeA and LaeA-like proteins, which are conserved in many filamentous fungi, regulate the sporogenesis and biosynthesis of secondary metabolites. In this study, we reported the biological function of a LaeA-like methyltransferase, Penicillium oxalicum Mtr23B, which contains a methyltransf_23 domain and an S-adenosylmethionine binding domain, in controlling spore pigment formation and in the expression of secondary metabolic gene cluster and glycoside hydrolase genes. Additionally, we compared Mtr23B and LaeA, and determined their similarities and differences in terms of their roles in regulating the above biological processes. mtr23B had the highest transcriptional level among the 12 members of the methyltransf_23 family in P. oxalicum. The colony color of Δmtr23B (deletion of mtr23B) was lighter than that of ΔlaeA, although Δmtr23B produced ~ 19.2-fold more conidia than ΔlaeA. The transcriptional levels of abrA, abrB/yA, albA/wA, arpA, arpB, and aygA, which are involved in the dihydroxynaphtalene-melanin pathway, decreased in Δmtr23B. However, Mtr23B had a little effect on brush-like structures and conidium formation, and had a different function from LaeA. Mtr23B extensively regulated glycoside hydrolase gene expression. The absence of Mtr23B remarkably repressed prominent cellulase- and amylase-encoding genes in the whole culture period, while the effect of LaeA mainly occurred in the later phases of prolonged batch cultures. Similar to LaeA, Mtr23B was involved in the expression of 10 physically linked regions containing secondary metabolic gene clusters; the highest regulatory activities of Mtr23B and LaeA were observed in BrlA-dependent cascades. Although LaeA interacted with VeA, Mtr23B did not interact with VeA directly. We assumed that Mtr23B regulates cellulase and amylase gene transcription by interacting with the CCAAT-binding transcription factor HAP5 and chromatin remodeling complex.
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Affiliation(s)
- Xiujun Zhang
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, No. 72 Binhai Road, Qingdao 266237, China; National Glycoengineering Research Center, Shandong University, No. 72 Binhai Road, Qingdao 266237, China.
| | - Mengxue Li
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, No. 72 Binhai Road, Qingdao 266237, China; National Glycoengineering Research Center, Shandong University, No. 72 Binhai Road, Qingdao 266237, China
| | - Yingying Zhu
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, No. 72 Binhai Road, Qingdao 266237, China
| | - Ling Yang
- Vocational Education College, Dezhou University, Dezhou 253023, China
| | - Yanan Li
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, No. 72 Binhai Road, Qingdao 266237, China; National Glycoengineering Research Center, Shandong University, No. 72 Binhai Road, Qingdao 266237, China
| | - Jingyao Qu
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, No. 72 Binhai Road, Qingdao 266237, China; National Glycoengineering Research Center, Shandong University, No. 72 Binhai Road, Qingdao 266237, China.
| | - Lushan Wang
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, No. 72 Binhai Road, Qingdao 266237, China.
| | - Jian Zhao
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, No. 72 Binhai Road, Qingdao 266237, China.
| | - Yinbo Qu
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, No. 72 Binhai Road, Qingdao 266237, China; National Glycoengineering Research Center, Shandong University, No. 72 Binhai Road, Qingdao 266237, China.
| | - Yuqi Qin
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, No. 72 Binhai Road, Qingdao 266237, China; National Glycoengineering Research Center, Shandong University, No. 72 Binhai Road, Qingdao 266237, China.
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16
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Li Y, Hu Y, Zhao K, Pan Y, Qu Y, Zhao J, Qin Y. The Indispensable Role of Histone Methyltransferase PoDot1 in Extracellular Glycoside Hydrolase Biosynthesis of Penicillium oxalicum. Front Microbiol 2019; 10:2566. [PMID: 31787956 PMCID: PMC6853848 DOI: 10.3389/fmicb.2019.02566] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 10/23/2019] [Indexed: 11/13/2022] Open
Abstract
Histone methylation is associated with transcription regulation, but its role for glycoside hydrolase (GH) biosynthesis is still poorly understood. We identified the histone H3 lysine 79 (H3K79)-specific methyltransferase PoDot1 in Penicillium oxalicum. PoDot1 affects conidiation by regulating the transcription of key regulators (BrlA, FlbC, and StuA) of asexual development and is required in normal hyphae septum and branch formation by regulating the transcription of five septin-encoding genes, namely, aspA, aspB, aspC, aspD, and aspE. Tandem affinity purification/mass spectrometry showed that PoDot1 has no direct interaction with transcription machinery, but it affects the expressions of extracellular GH genes extensively. The expression of genes (amy15A, amy13A, cel7A/cbh1, cel61A, chi18A, cel3A/bgl1, xyn10A, cel7B/eg1, cel5B/eg2, and cel6A/cbh2) that encode the top 10 GHs was remarkably downregulated by Podot1 deletion (ΔPodot1). Consistent with the decrease in gene transcription level, the activities of amylases and cellulases were significantly decreased in ΔPodot1 mutants in agar (solid) and fermentation (liquid) media. The repression of GH gene expressions caused by PoDot1 deletion was not mediated by key transcription factors, such as AmyR, ClrB, CreA, and XlnR, but was accompanied by defects in global demethylated H3K79 (H3K79me2) and trimethylated H3K79 (H3K79me3). The impairment of H3K79me2 on specific GH gene loci was observed due to PoDot1 deletion. The results implies that defects of H3K79 methylation is the key reason of the downregulated transcription level of GH-encoding genes and reveals the indispensable role of PoDot1 in extracellular GH biosynthesis.
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Affiliation(s)
- Yanan Li
- National Glycoengineering Research Center and State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China.,College of Life Sciences, Henan Agricultural University, Zhengzhou, China.,Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Qingdao, China
| | - Yueyan Hu
- National Glycoengineering Research Center and State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China.,Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Qingdao, China
| | - Kaili Zhao
- National Glycoengineering Research Center and State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China.,Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Qingdao, China
| | - Yunjun Pan
- National Glycoengineering Research Center and State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Yinbo Qu
- National Glycoengineering Research Center and State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China.,Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Qingdao, China
| | - Jian Zhao
- National Glycoengineering Research Center and State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Yuqi Qin
- National Glycoengineering Research Center and State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China.,Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Qingdao, China
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17
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Zhu C, Wang Y, Hu X, Lei M, Wang M, Zeng J, Li H, Liu Z, Zhou T, Yu D. Involvement of LaeA in the regulation of conidia production and stress responses in Penicillium digitatum. J Basic Microbiol 2019; 60:82-88. [PMID: 31650621 DOI: 10.1002/jobm.201900367] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 09/12/2019] [Accepted: 09/16/2019] [Indexed: 01/07/2023]
Abstract
Involvement of LaeA in various biological processes of filamentous fungi has been demonstrated. However, its role in Penicillium digitatum, the causal agent of citrus postharvest green mold, remains unclear. In this study, a ΔPdLaeA mutant was constructed using homologous recombination. The production of conidia by the ΔPdLaeA mutant was reduced by half compared with that of the wild-type strain. The sensitivity of the ΔPdLaeA mutant increased under alkaline conditions. The virulence assay revealed that PdLaeA was dispensable for the virulence of P. digitatum. Comparative transcriptome analysis revealed that the function loss of PdLaeA resulted in the reduced expression of several secondary metabolite gene clusters. In addition, expression of several key regulators of conidiation (BrlA, FlbA, FlbC, FlbD, and FluG) was also downregulated in the ΔPdLaeA mutant. In summary, the present work demonstrated that PdLaeA was involved in the regulation of SM biosynthesis, as well as the development and environmental adaptation of P. digitatum.
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Affiliation(s)
- Congyi Zhu
- Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization (MOA), Guangdong Province Key Laboratory of Tropical and Subtropical Fruit Tree Research, Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences, Guangzhou, China
| | - Yuying Wang
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Xu Hu
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Mengying Lei
- Department of Ecological Engineering, Guangdong Eco-Engineering Polytechnic, Guangzhou, China
| | - Mingshuang Wang
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Jiwu Zeng
- Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization (MOA), Guangdong Province Key Laboratory of Tropical and Subtropical Fruit Tree Research, Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences, Guangzhou, China
| | - Hongye Li
- Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Zheyu Liu
- Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization (MOA), Guangdong Province Key Laboratory of Tropical and Subtropical Fruit Tree Research, Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences, Guangzhou, China
| | - Ting Zhou
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Dongliang Yu
- College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, China
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18
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Song D, Shi Y, Ji H, Xia Y, Peng G. The MaCreA Gene Regulates Normal Conidiation and Microcycle Conidiation in Metarhizium acridum. Front Microbiol 2019; 10:1946. [PMID: 31497008 PMCID: PMC6713048 DOI: 10.3389/fmicb.2019.01946] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Accepted: 08/07/2019] [Indexed: 12/19/2022] Open
Abstract
As a C2H2 type zinc finger transcription factor, CreA is the key in Carbon Catabolism Repression (CCR) pathway, which negatively regulates the genes in carbon sources utilization. As conidiation in filamentous fungi is affected by nutritional conditions, CreA may contribute to fungal conidiation, which has been well studied in filamentous fungi, especially Aspergillus spp., but researches on entomopathogenic fungi are not enough. In this study, we found a homologous gene MaCreA in Metarhizium acridum, and the MaCreA deletion strain showed delayed conidiation, significant decrease in conidial yield, and 96.88% lower conidial production, when compared with the wild-type strain, and the normal conidiation and microcycle conidiation pattern shift was blocked. RT-qPCR showed that the transcription levels of the genes FlbD and LaeA (related to asexual development) were significantly altered, and those of most of the conidiation-related genes were higher in ΔMaCreA strain. The results of RNA-Seq revealed that MaCreA regulated the two conidiation patterns by mediating genes related to cell cycle, cell division, cell wall, and cell polarity. In conclusion, CreA, as a core regulatory gene in conidiation, provides new insight into the mechanism of conidiation in entomopathogenic fungi.
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Affiliation(s)
- Dongxu Song
- Genetic Engineering Research Center, School of Life Sciences, Chongqing University, Chongqing, China.,Chongqing Engineering Research Center for Fungal Insecticide, Chongqing, China.,Key Laboratory of Gene Function and Regulation Technologies Under Chongqing Municipal Education Commission, Chongqing, China
| | - Youhui Shi
- Genetic Engineering Research Center, School of Life Sciences, Chongqing University, Chongqing, China.,Chongqing Engineering Research Center for Fungal Insecticide, Chongqing, China.,Key Laboratory of Gene Function and Regulation Technologies Under Chongqing Municipal Education Commission, Chongqing, China
| | - HengQing Ji
- Chongqing Center for Disease Control and Prevention, Chongqing, China
| | - Yuxian Xia
- Genetic Engineering Research Center, School of Life Sciences, Chongqing University, Chongqing, China.,Chongqing Engineering Research Center for Fungal Insecticide, Chongqing, China.,Key Laboratory of Gene Function and Regulation Technologies Under Chongqing Municipal Education Commission, Chongqing, China
| | - Guoxiong Peng
- Genetic Engineering Research Center, School of Life Sciences, Chongqing University, Chongqing, China.,Chongqing Engineering Research Center for Fungal Insecticide, Chongqing, China.,Key Laboratory of Gene Function and Regulation Technologies Under Chongqing Municipal Education Commission, Chongqing, China
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Tannous J, Kumar D, Sela N, Sionov E, Prusky D, Keller NP. Fungal attack and host defence pathways unveiled in near-avirulent interactions of Penicillium expansum creA mutants on apples. MOLECULAR PLANT PATHOLOGY 2018; 19:2635-2650. [PMID: 30047230 PMCID: PMC6638163 DOI: 10.1111/mpp.12734] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Amongst the universal diseases affecting apples, blue mould caused by Penicillium expansum is a major concern, resulting in yield and quality losses as a result of the production of the mycotoxin patulin. Despite the characterization of the patulin biosynthetic gene cluster at both the molecular and chemical levels, the underlying regulation of patulin biosynthesis in P. expansum and the mechanisms of apple colonization remain largely obscure. Recent work has indicated that sucrose, a carbon catabolite repressive metabolite, is a critical factor in the regulation of patulin synthesis. Here, CreA, the global carbon catabolite regulator, was assessed for virulence both in vitro and in vivo. We showed that loss-of-function creA strains were nearly avirulent and did not produce patulin in apples. On the basis of RNA-sequencing (RNA-seq) analysis and physiological experimentation, these mutants were unable to successfully colonize apples for a multitude of potential mechanisms including, on the pathogen side, a decreased ability to produce proteolytic enzymes and to acidify the environment and impaired carbon/nitrogen metabolism and, on the host side, an increase in the oxidative defence pathways. Our study defines CreA and its downstream signalling pathways as promising targets for the development of strategies to fight against the development and virulence of this post-harvest pathogen.
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Affiliation(s)
- Joanna Tannous
- Department of Medical Microbiology and ImmunologyUniversity of Wisconsin – MadisonMadison 53706WIUSA
| | - Dilip Kumar
- Department of Postharvest Science of Fresh ProduceAgricultural Research Organization, The Volcani CenterBet Dagan50250Israel
| | - Noa Sela
- Department of Plant Pathology and Weed ResearchAgricultural Research Organization, The Volcani CenterBet Dagan50250Israel
| | - Edward Sionov
- Department of Food StorageAgricultural Research Organization, The Volcani CenterBet Dagan50250Israel
| | - Dov Prusky
- Department of Postharvest Science of Fresh ProduceAgricultural Research Organization, The Volcani CenterBet Dagan50250Israel
- College of Food Science and EngineeringGansu Agricultural UniversityYinmencun 1Anning District, Lanzhou730070China
| | - Nancy P. Keller
- Department of Medical Microbiology and ImmunologyUniversity of Wisconsin – MadisonMadison 53706WIUSA
- Department of BacteriologyUniversity of Wisconsin – MadisonMadison 53706WIUSA
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20
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Jain S, Sekonyela R, Knox BP, Palmer JM, Huttenlocher A, Kabbage M, Keller NP. Selenate sensitivity of a laeA mutant is restored by overexpression of the bZIP protein MetR in Aspergillus fumigatus. Fungal Genet Biol 2018; 117:1-10. [PMID: 29753128 PMCID: PMC6064392 DOI: 10.1016/j.fgb.2018.05.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Revised: 05/07/2018] [Accepted: 05/08/2018] [Indexed: 02/06/2023]
Abstract
LaeA is a conserved global regulator of secondary metabolism and development in filamentous fungi. Examination of Aspergillus fumigatus transcriptome data of laeA deletion mutants have been fruitful in identifying genes and molecules contributing to the laeA mutant phenotype. One of the genes significantly down regulated in A. fumigatus ΔlaeA is metR, encoding a bZIP DNA binding protein required for sulfur and methionine metabolism in fungi. LaeA and MetR deletion mutants exhibit several similarities including down regulation of sulfur assimilation and methionine metabolism genes and ability to grow on the toxic sulfur analog, sodium selenate. However, unlike ΔmetR, ΔlaeA strains are able to grow on sulfur, sulfite, and cysteine. To examine if any parameter of the ΔlaeA phenotype is due to decreased metR expression, an over-expression allele (OE::metR) was placed in a ΔlaeA background. The OE::metR allele could not significantly restore expression of MetR regulated genes in ΔlaeA but did restore sensitivity to sodium selenate. In A. nidulans a second bZIP protein, MetZ, also regulates sulfur and methionine metabolism genes. However, addition of an OE::metZ construct to the A. fumigatus ΔlaeA OE::metR strain still was unable to rescue the ΔlaeA phenotype to wildtype with regards gliotoxin synthesis and virulence in a zebrafish aspergillosis model.
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Affiliation(s)
- Sachin Jain
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI 53706, United States
| | - Relebohile Sekonyela
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, United States
| | - Benjamin P Knox
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI 53706, United States
| | - Jonathan M Palmer
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI 53706, United States
| | - Anna Huttenlocher
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI 53706, United States
| | - Mehdi Kabbage
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI 53706, United States
| | - Nancy P Keller
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, United States; Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI 53706, United States.
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Lind AL, Lim FY, Soukup AA, Keller NP, Rokas A. An LaeA- and BrlA-Dependent Cellular Network Governs Tissue-Specific Secondary Metabolism in the Human Pathogen Aspergillus fumigatus. mSphere 2018; 3:e00050-18. [PMID: 29564395 PMCID: PMC5853485 DOI: 10.1128/msphere.00050-18] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 02/21/2018] [Indexed: 12/17/2022] Open
Abstract
Biosynthesis of many ecologically important secondary metabolites (SMs) in filamentous fungi is controlled by several global transcriptional regulators, like the chromatin modifier LaeA, and tied to both development and vegetative growth. In Aspergillus molds, asexual development is regulated by the BrlA > AbaA > WetA transcriptional cascade. To elucidate BrlA pathway involvement in SM regulation, we examined the transcriptional and metabolic profiles of ΔbrlA, ΔabaA, and ΔwetA mutant and wild-type strains of the human pathogen Aspergillus fumigatus. We find that BrlA, in addition to regulating production of developmental SMs, regulates vegetative SMs and the SrbA-regulated hypoxia stress response in a concordant fashion to LaeA. We further show that the transcriptional and metabolic equivalence of the ΔbrlA and ΔlaeA mutations is mediated by an LaeA requirement preventing heterochromatic marks in the brlA promoter. These results provide a framework for the cellular network regulating not only fungal SMs but diverse cellular processes linked to virulence of this pathogen. IMPORTANCE Filamentous fungi produce a spectacular variety of small molecules, commonly known as secondary or specialized metabolites (SMs), which are critical to their ecologies and lifestyles (e.g., penicillin, cyclosporine, and aflatoxin). Elucidation of the regulatory network that governs SM production is a major question of both fundamental and applied research relevance. To shed light on the relationship between regulation of development and regulation of secondary metabolism in filamentous fungi, we performed global transcriptomic and metabolomic analyses on mutant and wild-type strains of the human pathogen Aspergillus fumigatus under conditions previously shown to induce the production of both vegetative growth-specific and asexual development-specific SMs. We find that the gene brlA, previously known as a master regulator of asexual development, is also a master regulator of secondary metabolism and other cellular processes. We further show that brlA regulation of SM is mediated by laeA, one of the master regulators of SM, providing a framework for the cellular network regulating not only fungal SMs but diverse cellular processes linked to virulence of this pathogen.
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Affiliation(s)
- Abigail L. Lind
- Department of Biomedical Informatics, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Fang Yun Lim
- Department of Medical Microbiology & Immunology, University of Wisconsin—Madison, Madison, Wisconsin, USA
| | - Alexandra A. Soukup
- Department of Genetics, University of Wisconsin—Madison, Madison, Wisconsin, USA
| | - Nancy P. Keller
- Department of Medical Microbiology & Immunology, University of Wisconsin—Madison, Madison, Wisconsin, USA
| | - Antonis Rokas
- Department of Biomedical Informatics, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
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Li Y, Zheng X, Zhang X, Bao L, Zhu Y, Qu Y, Zhao J, Qin Y. The Different Roles of Penicillium oxalicum LaeA in the Production of Extracellular Cellulase and β-xylosidase. Front Microbiol 2016; 7:2091. [PMID: 28066400 PMCID: PMC5177634 DOI: 10.3389/fmicb.2016.02091] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 12/09/2016] [Indexed: 12/16/2022] Open
Abstract
Cellulolytic enzyme hydrolysis of lignocellulose biomass to release fermentable sugars is one of the key steps in biofuel refining. Gene expression of fungal cellulolytic enzymes is tightly controlled at the transcriptional level. Key transcription factors such as activator ClrB/CLR2 and XlnR/XYR1, as well as repressor CreA/CRE1 play crucial roles in this process. The putative protein methyltransferase LaeA/LAE1 has also been reported to regulate the gene expression of the cellulolytic enzyme. The formation and gene expression of the cellulolytic enzyme was compared among Penicillium oxalicum wild type (WT) and seven mutants, including ΔlaeA (deletion of laeA), OEclrB (clrB overexpression), OEclrBΔlaeA (clrB overexpression with deletion of laeA), OExlnR (xlnR overexpression), OExlnRΔlaeA (xlnR overexpression with deletion of laeA), ΔcreA (deletion of creA), and ΔcreAΔlaeA (double deletion of creA and laeA). Results revealed that LaeA extensively affected the expression of glycoside hydrolase genes. The expression of genes that encoded the top 10 glycoside hydrolases assayed in secretome was remarkably downregulated especially in later phases of prolonged batch cultures by the deletion of laeA. Cellulase synthesis of four mutants ΔlaeA, OEclrBΔlaeA, OExlnRΔlaeA, and ΔcreAΔlaeA was repressed remarkably compared with their parent strains WT, OEclrB, OExlnR, and ΔcreA, respectively. The overexpression of clrB or xlnR could not rescue the impairment of cellulolytic enzyme gene expression and cellulase synthesis when LaeA was absent, suggesting that LaeA was necessary for the expression of cellulolytic enzyme gene activated by ClrB or XlnR. In contrast to LaeA positive roles in regulating prominent cellulase and hemicellulase, the extracellular β-xylosidase formation was negatively regulated by LaeA. The extracellular β-xylosidase activities improved over 5-fold in the OExlnRΔlaeA mutant compared with that of WT, and the expression of prominent β-xylosidase gene xyl3A was activated remarkably. The cumulative effect of LaeA and transcription factor XlnR has potential applications in the production of more β-xylosidase.
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Affiliation(s)
- Yanan Li
- State Key Lab of Microbial Technology and National Glycoengineering Research Center, Shandong UniversityJinan, China; Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong UniversityJinan, China
| | - Xiaoju Zheng
- State Key Lab of Microbial Technology and National Glycoengineering Research Center, Shandong University Jinan, China
| | - Xiujun Zhang
- State Key Lab of Microbial Technology and National Glycoengineering Research Center, Shandong University Jinan, China
| | - Longfei Bao
- State Key Lab of Microbial Technology and National Glycoengineering Research Center, Shandong University Jinan, China
| | - Yingying Zhu
- State Key Lab of Microbial Technology and National Glycoengineering Research Center, Shandong University Jinan, China
| | - Yinbo Qu
- State Key Lab of Microbial Technology and National Glycoengineering Research Center, Shandong University Jinan, China
| | - Jian Zhao
- State Key Lab of Microbial Technology and National Glycoengineering Research Center, Shandong University Jinan, China
| | - Yuqi Qin
- State Key Lab of Microbial Technology and National Glycoengineering Research Center, Shandong UniversityJinan, China; Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong UniversityJinan, China
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23
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Németh Z, Molnár ÁP, Fejes B, Novák L, Karaffa L, Keller NP, Fekete E. Growth-Phase Sterigmatocystin Formation on Lactose Is Mediated via Low Specific Growth Rates in Aspergillus nidulans. Toxins (Basel) 2016; 8:E354. [PMID: 27916804 PMCID: PMC5198170 DOI: 10.3390/toxins8120354] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2016] [Revised: 11/20/2016] [Accepted: 11/23/2016] [Indexed: 11/24/2022] Open
Abstract
Seed contamination with polyketide mycotoxins such as sterigmatocystin (ST) produced by Aspergilli is a worldwide issue. The ST biosynthetic pathway is well-characterized in A. nidulans, but regulatory aspects related to the carbon source are still enigmatic. This is particularly true for lactose, inasmuch as some ST production mutant strains still synthesize ST on lactose but not on other carbon substrates. Here, kinetic data revealed that on d-glucose, ST forms only after the sugar is depleted from the medium, while on lactose, ST appears when most of the carbon source is still available. Biomass-specified ST production on lactose was significantly higher than on d-glucose, suggesting that ST formation may either be mediated by a carbon catabolite regulatory mechanism, or induced by low specific growth rates attainable on lactose. These hypotheses were tested by d-glucose limited chemostat-type continuous fermentations. No ST formed at a high growth rate, while a low growth rate led to the formation of 0.4 mg·L-1 ST. Similar results were obtained with a CreA mutant strain. We concluded that low specific growth rates may be the primary cause of mid-growth ST formation on lactose in A. nidulans, and that carbon utilization rates likely play a general regulatory role during biosynthesis.
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Affiliation(s)
- Zoltán Németh
- Department of Biochemical Engineering, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, Debrecen H-4032, Hungary.
| | - Ákos P Molnár
- Department of Biochemical Engineering, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, Debrecen H-4032, Hungary.
| | - Balázs Fejes
- Department of Biochemical Engineering, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, Debrecen H-4032, Hungary.
| | - Levente Novák
- Department of Physical Chemistry, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, Debrecen H-4032, Hungary.
| | - Levente Karaffa
- Department of Biochemical Engineering, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, Debrecen H-4032, Hungary.
| | - Nancy P Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706, USA.
- Department of Bacteriology, University of Wisconsin, Madison, WI 53706, USA.
| | - Erzsébet Fekete
- Department of Biochemical Engineering, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, Debrecen H-4032, Hungary.
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