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Xie C, Shang Q, Mo C, Xiao Y, Wang G, Xie J, Jiang D, Xiao X. Early Secretory Pathway-Associated Proteins SsEmp24 and SsErv25 Are Involved in Morphogenesis and Pathogenicity in a Filamentous Phytopathogenic Fungus. mBio 2021; 12:e0317321. [PMID: 34933451 PMCID: PMC8689567 DOI: 10.1128/mbio.03173-21] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 11/15/2021] [Indexed: 12/28/2022] Open
Abstract
Proper protein secretion is critical for fungal development and pathogenesis. However, the potential roles of proteins involved in the early secretory pathway are largely undescribed in filamentous fungi. p24 proteins are cargo receptors that cycle between the endoplasmic reticulum (ER) and Golgi apparatus in the early secretory pathway and recruit cargo proteins to nascent vesicles. This study characterized the function of two p24 family proteins (SsEmp24 and SsErv25) in a phytopathogenic fungus, Sclerotinia sclerotiorum. Both SsEmp24 and SsErv25 were upregulated during the early stages of S. sclerotiorum infection. ΔSsEmp24 mutant and ΔSsErv25 mutant displayed abnormal vegetative growth and sclerotium formation, were defective in infection cushion formation, and showed lower virulence on host plants. ΔSsEmp24 mutant had a more severe abnormal phenotype than ΔSsErv25 mutant, implying that SsEmp24 could play a central role in the early secretory pathway. Similar to their Saccharomyces cerevisiae counterparts, SsEmp24 interacted with SsErv25 and predominantly colocalized in the ER or nuclear envelope. The absence of SsEmp24 or SsErv25 led to defective in protein secretion in S. sclerotiorum, including the pathogenicity-related extracellular hydrolytic enzymes and effectors. It is proposed that SsEmp24 and SsErv25, components in the early secretory pathway, are involved in modulating morphogenesis and pathogenicity in S. sclerotiorum by mediating protein secretion. IMPORTANCE Understanding the reproduction and pathogenesis mechanism of phytopathogens could provide new opinions to effectively control fungal diseases. Although it has been known that effectors and extracellular hydrolytic enzymes secreted by phytopathogenic fungi play important roles in fungus-host interactions, the secretion system for the delivery of virulence factors to the host is still largely undescribed. Although the role of the early secretory pathway-associated p24 proteins in S. cerevisiae has been well characterized, the function of these proteins in filamentous fungi was scarcely known prior to this study. The present research provides evidence that p24 proteins participate in the reproduction and pathogenesis of phytopathogenic fungi through the mediation of protein secretion. This research advances our understanding of p24 proteins in filamentous phytopathogenic fungi. In addition, the candidate cargos of the two p24 proteins, SsEmp24 and SsErv25, were screened out by comparative proteomics, which could aid the identification of novel development and virulence-associated factors in phytopathogenic fungi.
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Affiliation(s)
- Chong Xie
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei Province, China
- Hubei Key Laboratory of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei Province, China
| | - Qingna Shang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei Province, China
- Hubei Key Laboratory of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei Province, China
- Hubei Hongshan Laboratory, Wuhan, Hubei Province, China
| | - Chenmi Mo
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei Province, China
- Hubei Key Laboratory of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei Province, China
| | - Yannong Xiao
- Hubei Key Laboratory of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei Province, China
| | - Gaofeng Wang
- Hubei Key Laboratory of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei Province, China
| | - Jiatao Xie
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei Province, China
- Hubei Key Laboratory of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei Province, China
- Hubei Hongshan Laboratory, Wuhan, Hubei Province, China
| | - Daohong Jiang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei Province, China
- Hubei Key Laboratory of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei Province, China
- Hubei Hongshan Laboratory, Wuhan, Hubei Province, China
| | - Xueqiong Xiao
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei Province, China
- Hubei Key Laboratory of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei Province, China
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Wang F, Zhang R, Han L, Guo W, Du Z, Niu K, Liu Y, Jia C, Fang X. Use of fusion transcription factors to reprogram cellulase transcription and enable efficient cellulase production in Trichoderma reesei. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:244. [PMID: 31636703 PMCID: PMC6792246 DOI: 10.1186/s13068-019-1589-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 10/09/2019] [Indexed: 05/23/2023]
Abstract
BACKGROUND Trichoderma reesei is widely used for cellulase production and accepted as an example for cellulase research. Cre1-mediated carbon catabolite repression (CCR) can significantly inhibit the transcription of cellulase genes during cellulase fermentation in T. reesei. Early efforts have been undertaken to modify Cre1 for the release of CCR; however, this approach leads to arrested hyphal growth and decreased biomass accumulation, which negatively affects cellulase production. RESULTS In this study, novel fusion transcription factors (fTFs) were designed to release or attenuate CCR inhibition in cellulase transcription, while Cre1 was left intact to maintain normal hyphal growth. Four designed fTFs were introduced into the T. reesei genome, which generated several transformants, named Kuace3, Kuclr2, Kuace2, and Kuxyr1. No obvious differences in growth were observed between the parent and transformant strains. However, the transcription levels of cel7a, a major cellulase gene, were significantly elevated in all the transformants, particularly in Kuace2 and Kuxyr1, when grown on lactose as a carbon source. This suggested that CCR inhibition was released or attenuated in the transformant strains. The growth of Kuace2 and Kuxyr1 was approximately equivalent to that of the parent strain in fed-batch fermentation process. However, we observed a 3.2- and 2.1-fold increase in the pNPCase titers of the Kuace2 and Kuxyr1 strains, respectively, compared with that of the parent strain. Moreover, we observed a 6.1- and 3.9-fold increase in the pNPCase titers of the Kuace2 and Kuxyr1 strains, respectively, compared with that of Δcre1 strain. CONCLUSIONS A new strategy based on fTFs was successfully established in T. reesei to improve cellulase titers without impairing fungal growth. This study will be valuable for lignocellulosic biorefining and for guiding the development of engineering strategies for producing other important biochemical compounds in fungal species.
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Affiliation(s)
- Fangzhong Wang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237 China
- Center for Biosafety Research and Strategy, Tianjin University, Tianjin, China
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong China
| | - Ruiqin Zhang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237 China
| | - Lijuan Han
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237 China
| | - Wei Guo
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237 China
| | - Zhiqiang Du
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237 China
| | - Kangle Niu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237 China
| | - Yucui Liu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237 China
| | - Chunjiang Jia
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong China
| | - Xu Fang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237 China
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Fang X, Qu Y. Metabolic Engineering of Fungal Strains for Efficient Production of Cellulolytic Enzymes. FUNGAL CELLULOLYTIC ENZYMES 2018:27-41. [PMCID: PMC7120360 DOI: 10.1007/978-981-13-0749-2_2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Filamentous fungi are widely used for production of cellulase and other cellulolytic enzymes. Metabolic engineering of filamentous fungal strains has been applied to improve enzyme production, and rapid progress has been made in the recent years. In this chapter, genetic tools and methods to develop superior enzyme producers are summarized, which includes establishment of genetic modification systems, selection and redesign of promoters, and metabolic engineering using either native transcription factors or artificial ones. In addition, enhancement of cellulase production through morphology engineering was also discussed. Emerging tools including CRISPR-Cas9-based genome editing and synthetic biology are highlighted, which are speeding up mechanisms elucidation and strain development, and will further facilitate economic cellulolytic enzyme production.
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Affiliation(s)
- Xu Fang
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, Shandong China
| | - Yinbo Qu
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, Shandong China
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Starr TL, Gonçalves AP, Meshgin N, Glass NL. The major cellulases CBH-1 and CBH-2 of Neurospora crassa rely on distinct ER cargo adaptors for efficient ER-exit. Mol Microbiol 2017; 107:229-248. [PMID: 29131484 DOI: 10.1111/mmi.13879] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/10/2017] [Indexed: 12/17/2022]
Abstract
Filamentous fungi are native secretors of lignocellulolytic enzymes and are used as protein-producing factories in the industrial biotechnology sector. Despite the importance of these organisms in industry, relatively little is known about the filamentous fungal secretory pathway or how it might be manipulated for improved protein production. Here, we use Neurospora crassa as a model filamentous fungus to interrogate the requirements for trafficking of cellulase enzymes from the endoplasmic reticulum to the Golgi. We characterized the localization and interaction properties of the p24 and ERV-29 cargo adaptors, as well as their role in cellulase enzyme trafficking. We find that the two most abundantly secreted cellulases, CBH-1 and CBH-2, depend on distinct ER cargo adaptors for efficient exit from the ER. CBH-1 depends on the p24 proteins, whereas CBH-2 depends on the N. crassa homolog of yeast Erv29p. This study provides a first step in characterizing distinct trafficking pathways of lignocellulolytic enzymes in filamentous fungi.
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Affiliation(s)
- Trevor L Starr
- The Energy Biosciences Institute, The University of California, Berkeley, CA 94720, USA
| | - A Pedro Gonçalves
- The Energy Biosciences Institute, The University of California, Berkeley, CA 94720, USA.,Plant and Microbial Biology Department, The University of California, Berkeley, CA 94720, USA
| | - Neeka Meshgin
- The Energy Biosciences Institute, The University of California, Berkeley, CA 94720, USA
| | - N Louise Glass
- The Energy Biosciences Institute, The University of California, Berkeley, CA 94720, USA.,Plant and Microbial Biology Department, The University of California, Berkeley, CA 94720, USA.,Environmental Genomics and Systems Biology Division, The Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
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Jiang B, Zhang R, Feng D, Wang F, Liu K, Jiang Y, Niu K, Yuan Q, Wang M, Wang H, Zhang Y, Fang X. A Tet-on and Cre-loxP Based Genetic Engineering System for Convenient Recycling of Selection Markers in Penicillium oxalicum. Front Microbiol 2016; 7:485. [PMID: 27148179 PMCID: PMC4828452 DOI: 10.3389/fmicb.2016.00485] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2015] [Accepted: 03/23/2016] [Indexed: 01/15/2023] Open
Abstract
The lack of selective markers has been a key problem preventing multistep genetic engineering in filamentous fungi, particularly for industrial species such as the lignocellulose degrading Penicillium oxalicum JUA10-1(formerly named as Penicillium decumbens). To resolve this problem, we constructed a genetic manipulation system taking advantage of two established genetic systems: the Cre-loxP system and Tet-on system in P. oxalicum JUA10-1. This system is efficient and convenient. The expression of Cre recombinase was activated by doxycycline since it was controlled by Tet-on system. Using this system, two genes, ligD and bglI, were sequentially disrupted by loxP flanked ptrA. The successful application of this procedure will provide a useful tool for genetic engineering in filamentous fungi. This system will also play an important role in improving the productivity of interesting products and minimizing by-product when fermented by filamentous fungi.
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Affiliation(s)
- Baojie Jiang
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University Jinan, China
| | - Ruiqin Zhang
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University Jinan, China
| | - Dan Feng
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University Jinan, China
| | - Fangzhong Wang
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University Jinan, China
| | - Kuimei Liu
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University Jinan, China
| | - Yi Jiang
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University Jinan, China
| | - Kangle Niu
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University Jinan, China
| | - Quanquan Yuan
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University Jinan, China
| | - Mingyu Wang
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University Jinan, China
| | - Hailong Wang
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong UniversityJinan, China; State Key Laboratory of Microbial Technology, School of Life Science, Shandong University-Helmholtz Institute of Biotechnology, Shandong UniversityJinan, China
| | - Youming Zhang
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong UniversityJinan, China; State Key Laboratory of Microbial Technology, School of Life Science, Shandong University-Helmholtz Institute of Biotechnology, Shandong UniversityJinan, China
| | - Xu Fang
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University Jinan, China
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Liu K, Dong Y, Wang F, Jiang B, Wang M, Fang X. Regulation of cellulase expression, sporulation, and morphogenesis by velvet family proteins in Trichoderma reesei. Appl Microbiol Biotechnol 2015; 100:769-79. [PMID: 26481618 DOI: 10.1007/s00253-015-7059-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Revised: 09/23/2015] [Accepted: 09/29/2015] [Indexed: 11/24/2022]
Abstract
Homologs of the velvet protein family are encoded by the ve1, vel2, and vel3 genes in Trichoderma reesei. To test their regulatory functions, the velvet protein-coding genes were disrupted, generating Δve1, Δvel2, and Δvel3 strains. The phenotypic features of these strains were examined to identify their functions in morphogenesis, sporulation, and cellulase expression. The three velvet-deficient strains produced more hyphal branches, indicating that velvet family proteins participate in the morphogenesis in T. reesei. Deletion of ve1 and vel3 did not affect biomass accumulation, while deletion of vel2 led to a significantly hampered growth when cellulose was used as the sole carbon source in the medium. The deletion of either ve1 or vel2 led to the sharp decrease of sporulation as well as a global downregulation of cellulase-coding genes. In contrast, although the expression of cellulase-coding genes of the ∆vel3 strain was downregulated in the dark, their expression in light condition was unaffected. Sporulation was hampered in the ∆vel3 strain. These results suggest that Ve1 and Vel2 play major roles, whereas Vel3 plays a minor role in sporulation, morphogenesis, and cellulase expression.
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Affiliation(s)
- Kuimei Liu
- State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, 250100, China
| | - Yanmei Dong
- State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, 250100, China
| | - Fangzhong Wang
- State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, 250100, China
| | - Baojie Jiang
- State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, 250100, China
| | - Mingyu Wang
- State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, 250100, China
| | - Xu Fang
- State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, 250100, China.
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Wang F, Liu K, Han L, Jiang B, Wang M, Fang X. Function of a p24 Heterodimer in Morphogenesis and Protein Transport in Penicillium oxalicum. Sci Rep 2015; 5:11875. [PMID: 26149342 PMCID: PMC4493713 DOI: 10.1038/srep11875] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 06/05/2015] [Indexed: 12/11/2022] Open
Abstract
The lignocellulose degradation capacity of filamentous fungi has been widely studied because of their cellulase hypersecretion. The p24 proteins in eukaryotes serve important functions in this secretory pathway. However, little is known about the functions of the p24 proteins in filamentous fungi. In this study, four p24 proteins were identified in Penicillium oxalicum. Six p24 double-deletion strains were constructed, and further studies were carried out with the ΔerpΔpδ strain. The experimental results suggested that Erp and Pδ form a p24 heterodimer in vivo. This p24 heterodimer participates in important morphogenetic events, including sporulation, hyphal growth, and lateral branching. The results suggested that the p24 heterodimer mediates protein transport, particularly that of cellobiohydrolase. Analysis of the intracellular proteome revealed that the ΔerpΔpδ double mutant is under secretion stress due to attempts to remove proteins that are jammed in the endomembrane system. These results suggest that the p24 heterodimer participates in morphogenesis and protein transport. Compared with P. oxalicum Δerp, a greater number of cellular physiological pathways were impaired in ΔerpΔpδ. This finding may provide new insights into the secretory pathways of filamentous fungi.
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Affiliation(s)
- Fangzhong Wang
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, Shandong, China
| | - Kuimei Liu
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, Shandong, China
| | - Lijuan Han
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, Shandong, China
| | - Baojie Jiang
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, Shandong, China
| | - Mingyu Wang
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, Shandong, China
| | - Xu Fang
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, Shandong, China
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Functional analysis of Trichoderma reesei CKIIα2, a catalytic subunit of casein kinase II. Appl Microbiol Biotechnol 2015; 99:5929-38. [DOI: 10.1007/s00253-015-6544-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Revised: 03/12/2015] [Accepted: 03/13/2015] [Indexed: 11/26/2022]
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