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du Plooy LM, Telzrow CL, Nichols CB, Probst C, Castro-Lopez N, Wormley FL, Alspaugh JA. A fungal ubiquitin ligase and arrestin binding partner contribute to pathogenesis and survival during cellular stress. mBio 2024:e0098124. [PMID: 39235249 DOI: 10.1128/mbio.00981-24] [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: 04/04/2024] [Accepted: 07/29/2024] [Indexed: 09/06/2024] Open
Abstract
Cellular responses to external stress allow microorganisms to adapt to a vast array of environmental conditions, including infection sites. The molecular mechanisms behind these responses are studied to gain insight into microbial pathogenesis, which could lead to new antimicrobial therapies. Here, we explore a role for arrestin protein-mediated ubiquitination in stress response and pathogenesis in the pathogenic fungus Cryptococcus neoformans. In a previous study, we identified four arrestin-like proteins in C. neoformans and found that one of these is required for efficient membrane synthesis, likely by directing interaction between fatty acid synthases and the Rsp5 E3 ubiquitin ligase. Here, we further explore Cn Rsp5 function and determine that this single Ub ligase is absolutely required for pathogenesis and survival in the presence of cellular stress. Additionally, we show that a second arrestin-like protein, Ali2, similarly facilitates interaction between Rsp5 and some of its protein targets. Of the four postulated C. neoformans arrestin-like proteins, Ali2 appears to contribute the most to C. neoformans pathogenesis, likely by directing Rsp5 to pathogenesis-related ubiquitination targets. A proteomics-based differential ubiquitination screen revealed that several known cell surface proteins are ubiquitinated by Rsp5 and a subset also requires Ali2 for their ubiquitination. Rsp5-mediated ubiquitination alters the stability and the localization of these proteins. A loss of Rsp5-mediated ubiquitination results in cell wall defects that increase susceptibility to external stresses. These findings support a model in which arrestin-like proteins guide Rsp5 to ubiquitinate specific target proteins, some of which are required for survival during stress. IMPORTANCE Microbial proteins involved in human infectious diseases often need to be modified by specific chemical additions to be fully functional. Here, we explore the role of a particular protein modification, ubiquitination, in infections due to the human fungal pathogen Cryptococcus neoformans. We identified a complex of proteins responsible for adding ubiquitin groups to fungal proteins, and this complex is required for virulence. These proteins are fungal specific and might be targets for novel anti-infection therapy.
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Affiliation(s)
- Lukas M du Plooy
- Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, North Carolina, USA
| | - Calla L Telzrow
- Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, North Carolina, USA
| | - Connie B Nichols
- Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
| | - Corinna Probst
- Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
| | - Natalia Castro-Lopez
- Department of Biology, University of Texas at San Antonio, San Antonio, Texas, USA
- Department of Biology, Texas Christian University, Fort Worth, Texas, USA
| | - Floyd L Wormley
- Department of Biology, University of Texas at San Antonio, San Antonio, Texas, USA
- Department of Biology, Texas Christian University, Fort Worth, Texas, USA
| | - J Andrew Alspaugh
- Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, North Carolina, USA
- Department of Cell Biology, Duke University School of Medicine, Durham, North Carolina, USA
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Zhang H, Chen H, Zhang J, Wang K, Huang B, Wang Z. The role of MrUbp4, a deubiquitinase, in conidial yield, thermotolerance, and virulence in Metarhizium robertsii. J Invertebr Pathol 2024; 204:108111. [PMID: 38631560 DOI: 10.1016/j.jip.2024.108111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Revised: 03/18/2024] [Accepted: 04/14/2024] [Indexed: 04/19/2024]
Abstract
Ubiquitin-specific proteases (UBPs), the largest subfamily of deubiquitinating enzymes, regulate ubiquitin homeostasis and play diverse roles in eukaryotes. Ubp4 is essential for the growth, development, and pathogenicity of various fungal pathogens. However, its functions in the growth, stress responses, and virulence of entomopathogenic fungi remain unclear. In this study, we elucidated the role of the homolog of Ubp4, MrUbp4, in the entomopathogenic fungus Metarhizium robertsii. Deletion of MrUbp4 led to a notable increase in ubiquitination levels, demonstrating the involvement of MrUbp4 in protein deubiquitination. Furthermore, the ΔMrUbp4 mutant displayed a significant reduction in conidial yield, underscoring the pivotal role of MrUbp4 in conidiation. Additionally, the mutant exhibited heightened resistance to conidial heat treatment, emphasizing the role of MrUbp4 in thermotolerance. Notably, insect bioassays unveiled a substantial impairment in the virulence of the ΔMrUbp4 mutant. This was accompanied by a notable decrease in cuticle penetration ability and appressorium formation upon further analysis. In summary, our findings highlight the essential role of MrUbp4 in regulating the conidial yield, thermotolerance, and contributions to the virulence of M. robertsii.
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Affiliation(s)
- Hongzhi Zhang
- Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, School of Plant Protection, Anhui Agricultural University, Hefei 230036, China; Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei 230036, China
| | - Hanyuan Chen
- Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, School of Plant Protection, Anhui Agricultural University, Hefei 230036, China; Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei 230036, China
| | - Jianfeng Zhang
- Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, School of Plant Protection, Anhui Agricultural University, Hefei 230036, China; Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei 230036, China
| | - Kui Wang
- Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, School of Plant Protection, Anhui Agricultural University, Hefei 230036, China; Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei 230036, China
| | - Bo Huang
- Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei 230036, China.
| | - Zhangxun Wang
- Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, School of Plant Protection, Anhui Agricultural University, Hefei 230036, China; Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei 230036, China.
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3
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Ueno K, Nagamori A, Honkyu NO, Kataoka M, Shimizu K, Chang YC, Kwon-Chung KJ, Miyazaki Y. Cryptococcus neoformans requires the TVF1 gene for thermotolerance and virulence. Med Mycol 2023; 61:myad101. [PMID: 37818721 PMCID: PMC10565887 DOI: 10.1093/mmy/myad101] [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: 07/11/2023] [Revised: 09/13/2023] [Accepted: 09/26/2023] [Indexed: 09/29/2023] Open
Abstract
Cryptococcus neoformans is the primary causative agent of cryptococcosis. Since C. neoformans thrives in environments and its optimal growth temperature is 25-30°C, it needs to adapt to heat stress in order to cause infection in mammalian hosts. In this study, we aimed to investigate the role of an uncharacterized gene, CNAG_03308. Although the CNAG_03308 deletion strain grew as well as the parent strain KN99, it produced yeast cells with abnormal morphology at 37°C and failed to propagate at 39°C. Furthermore, the deletion strain exhibited slower growth at 37°C in the presence of congo red, which is a cell wall stressor. When cultured at 39°C, the deletion strain showed strong staining with fluorescent probes for cell wall chitin and chitosan, including FITC-labeled wheat germ agglutinin, Eosin Y, and calcofluor white. The transmission electron microscopy of the deletion strain revealed a thickened inner layer of the cell wall containing chitin and chitosan under heat stress. This cell-surface altered deletion strain induced dendritic cells to secrete more interleukin (IL)-6 and IL-23 than the control strains under heat stress. In a murine infection study, C57BL/6 mice infected with the deletion strain exhibited lower mortality and lower fungal burden in the lungs and brain compared to those infected with the control strains. Based on these findings, we concluded that CNAG_03308 gene is necessary for C. neoformans to adapt to heat stress both in vitro and in the host environment. Therefore, we designated the CNAG_03308 gene as TVF1, which stands for thermotolerance and virulence-related factor 1.
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Affiliation(s)
- Keigo Ueno
- Department of Fungal Infection, National Institute of Infectious Diseases, Tokyo 162-8640, Japan
| | - Akiko Nagamori
- Department of Fungal Infection, National Institute of Infectious Diseases, Tokyo 162-8640, Japan
| | - Nahoko Oniyama Honkyu
- Department of Fungal Infection, National Institute of Infectious Diseases, Tokyo 162-8640, Japan
| | - Michiyo Kataoka
- Department of Pathology, National Institute of Infectious Diseases, Tokyo 162-8640, Japan
| | - Kiminori Shimizu
- Department of Biological Science and Technology, Tokyo University of Science, Tokyo 125-8585, Japan
| | - Yun C Chang
- Molecular Microbiology Section, Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Kyung J Kwon-Chung
- Molecular Microbiology Section, Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Yoshitsugu Miyazaki
- Department of Fungal Infection, National Institute of Infectious Diseases, Tokyo 162-8640, Japan
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Noman M, Azizullah, Ahmed T, Gao Y, Wang H, Xiong X, Wang J, Lou J, Li D, Song F. Degradation of α-Subunits, Doa1 and Doa4, are Critical for Growth, Development, Programmed Cell Death Events, Stress Responses, and Pathogenicity in the Watermelon Fusarium Wilt Fungus Fusarium oxysporum f. sp. niveum. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023. [PMID: 37486296 DOI: 10.1021/acs.jafc.3c01785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/25/2023]
Abstract
The ubiquitin-proteasome system (UPS) regulates protein quality or control and plays essential roles in several biological and biochemical processes in fungi. Here, we present the characterization of two UPS components, FonDoa1 and FonDoa4, in watermelon Fusarium wilt fungus, Fusarium oxysporum f. sp. niveum (Fon), and their biological functions. FonDoa1 localizes in both the nucleus and cytoplasm, while FonDoa4 is predominantly present in the cytoplasm. Both genes show higher expression in germinating macroconidia at 12 h. Deletion of FonDoa1 or FonDoa4 affects vegetative growth, conidiation, conidial germination/morphology, apoptosis, and responses to environmental stressors. FonDoa1, but not FonDoa4, positively regulates autophagy. The targeted disruption mutants exhibit significantly attenuated pathogenicity on watermelon due to defects in the infection process and invasive fungal growth. Further results indicate that the WD40, PFU, and PUL domains are essential for the function of FonDoa1 in Fon pathogenicity and environmental stress responses. These findings demonstrate the previously uncharacterized biological functions of FonDoa1 and FonDoa4 in phytopathogenic fungi, providing potential targets for developing strategies to control watermelon Fusarium wilt.
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Affiliation(s)
- Muhammad Noman
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
- Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Azizullah
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
- Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Temoor Ahmed
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
- Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
- Xianghu Laboratory, Hangzhou 311231, China
| | - Yizhou Gao
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
- Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Hui Wang
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
- Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Xiaohui Xiong
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
- Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Jiajing Wang
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
- Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Jiajun Lou
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
- Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Dayong Li
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
- Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Fengming Song
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
- Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
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5
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Multiple F-Box Proteins Collectively Regulate Cell Development and Pathogenesis in the Human Pathogen Cryptococcus neoformans. J Fungi (Basel) 2022; 8:jof8121259. [PMID: 36547592 PMCID: PMC9781138 DOI: 10.3390/jof8121259] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 11/27/2022] [Accepted: 11/28/2022] [Indexed: 12/02/2022] Open
Abstract
The ubiquitin-proteasome system (UPS) mediates intracellular proteins degradation that influences various cellular functions in eukaryotic cells. The UPS is also involved in the development and virulence of pathogenic fungi. F-box proteins, which are part of the SCF (Skp1-Cullin-F-box protein) ligase, are a key component of UPS and are essential for the recognition of specific substrates. In this study, we identified 20 F-box proteins in C. neoformans and obtained deletion mutants for 19 of them. A comprehensive phenotypic analysis of these mutants revealed the diverse function of F-box proteins in stress response, cell size regulation, sexual reproduction, antifungal drug resistance, and fungal virulence in C. neoformans. The importance of three F-box proteins: Fbp4, Fbp8, and Fbp11, in these cellular functions were characterized in detail. This study provides an overall view of the F-box gene family in C. neoformans, which will lead to a better understanding of the function of fungal SCF E3 ligase-mediated UPS in fungal development and pathogenesis.
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Yang YL, Fan YB, Gao L, Zhang C, Gu JL, Pan WH, Fang W. Cryptococcus neoformans Csn1201 Is Associated With Pulmonary Immune Responses and Disseminated Infection. Front Immunol 2022; 13:890258. [PMID: 35720283 PMCID: PMC9201341 DOI: 10.3389/fimmu.2022.890258] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Accepted: 05/09/2022] [Indexed: 11/21/2022] Open
Abstract
Cryptococcus neoformans is a major etiological agent of fungal meningoencephalitis. The outcome of cryptococcosis depends on the complex interactions between the pathogenic fungus and host immunity. The understanding of how C. neoformans manipulates the host immune response through its pathogenic factors remains incomplete. In this study, we defined the roles of a previously uncharacterized protein, Csn1201, in cryptococcal fitness and host immunity. Use of both inhalational and intravenous mouse models demonstrated that the CSN1201 deletion significantly blocked the pulmonary infection and extrapulmonary dissemination of C. neoformans. The in vivo hypovirulent phenotype of the csn1201Δ mutant was attributed to a combination of multiple factors, including preferential dendritic cell accumulation, enhanced Th1 and Th17 immune responses, decreased intracellular survival inside macrophages, and attenuated blood–brain barrier transcytosis rather than exclusively to pathogenic fitness. The csn1201Δ mutant exhibited decreased tolerance to various stressors in vitro, along with reduced capsule production and enhanced cell wall thickness under host-relevant conditions, indicating that the CSN1201 deletion might promote the exposure of cell wall components and thus induce a protective immune response. Taken together, our results strongly support the importance of cryptococcal Csn1201 in pulmonary immune responses and disseminated infection.
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Affiliation(s)
- Ya-Li Yang
- Department of Dermatology, Shanghai Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, Shanghai, China.,Department of Laser and Aesthetic Medicine, Shanghai Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, Shanghai, China.,Shanghai Key Laboratory of Molecular Medical Mycology, Department of Dermatology and Venereology, Changzheng Hospital, Naval Military Medical University, Shanghai, China
| | - Yi-Bin Fan
- Department of Dermatology, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, China
| | - Lei Gao
- Microscopy Core Facility, Biomedical Research Core Facilities, Westlake University, Hangzhou, China
| | - Chao Zhang
- Shanghai Key Laboratory of Molecular Medical Mycology, Department of Dermatology and Venereology, Changzheng Hospital, Naval Military Medical University, Shanghai, China
| | - Ju-Lin Gu
- Department of Dermatology, Third Affiliated Hospital of Naval Military Medical University, Shanghai, China
| | - Wei-Hua Pan
- Shanghai Key Laboratory of Molecular Medical Mycology, Department of Dermatology and Venereology, Changzheng Hospital, Naval Military Medical University, Shanghai, China
| | - Wei Fang
- Department of Laser and Aesthetic Medicine, Shanghai Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, Shanghai, China.,Shanghai Key Laboratory of Molecular Medical Mycology, Department of Dermatology and Venereology, Changzheng Hospital, Naval Military Medical University, Shanghai, China
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7
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Wang Z, Chen H, Li H, Chen H, Huang B. The Deubiquitinating Enzyme MrUbp14 Is Involved in Conidiation, Stress Response, and Pathogenicity in Metarhizium robertsii. FRONTIERS IN FUNGAL BIOLOGY 2022; 3:896466. [PMID: 37746165 PMCID: PMC10512391 DOI: 10.3389/ffunb.2022.896466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 04/15/2022] [Indexed: 09/26/2023]
Abstract
Protein ubiquitination, which is involved in various biological processes in eukaryotic cells, is a reversible modification of proteins. Deubiquitinases can maintain ubiquitin homeostasis by removing ubiquitin or modulating protein degradation via the ubiquitin-proteasome system (UPS). Metarhizium robertsii, an entomopathogenic fungus, has become a model fungus for investigating the interactions between insects and fungal pathogens. To explore the possible effects of the deubiquitination process on the development, stress response, and virulence of M. robertsii, disruption of MrUbp14 (an ortholog of the yeast ubiquitin-specific protease gene, Ubp14) was performed. The results of this study showed that the deletion of MrUbp14 led to accelerated conidial germination, reduced conidial yields, and decreased expression levels of some genes involved in conidiation. Furthermore, the MrUbp14 mutant (ΔMrUbp14) exhibited decreased tolerance to cell wall-damaging stressors (Congo red and SDS) and heat stress. Importantly, the results of the bioassay demonstrated that the fungal virulence of the ΔMrUbp14 strain was largely reduced in cuticle infection, but not in direct injection, which was accompanied by a significant decline in appressorium formation and cuticle penetration. Moreover, our results demonstrated that the disruption of MrUbp14 resulted in significantly increased ubiquitination levels of total protein, suggesting that MrUbp14 acts as a deubiquitinating enzyme in M. robertsii. In summary, our phenotypic changes in the gene disruption mutants suggest that MrUbp14 is important for conidiation, stress response, and fungal virulence in M. robertsii.
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Affiliation(s)
- Zhangxun Wang
- Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei, China
- Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, School of Plant Protection, Anhui Agricultural University, Hefei, China
| | - Hua Chen
- Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei, China
- Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, School of Plant Protection, Anhui Agricultural University, Hefei, China
| | - Hao Li
- Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei, China
- Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, School of Plant Protection, Anhui Agricultural University, Hefei, China
| | - Hanyuan Chen
- Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei, China
- Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, School of Plant Protection, Anhui Agricultural University, Hefei, China
| | - Bo Huang
- Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei, China
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8
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Cao C, Xue C. More Than Just Cleaning: Ubiquitin-Mediated Proteolysis in Fungal Pathogenesis. Front Cell Infect Microbiol 2021; 11:774613. [PMID: 34858882 PMCID: PMC8631298 DOI: 10.3389/fcimb.2021.774613] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Accepted: 10/25/2021] [Indexed: 12/14/2022] Open
Abstract
Ubiquitin-proteasome mediated protein turnover is an important regulatory mechanism of cellular function in eukaryotes. Extensive studies have linked the ubiquitin-proteasome system (UPS) to human diseases, and an array of proteasome inhibitors have been successfully developed for cancer therapy. Although still an emerging field, research on UPS regulation of fungal development and virulence has been rapidly advancing and has generated considerable excitement in its potential as a target for novel drugs. In this review, we summarize UPS composition and regulatory function in pathogenic fungi, especially in stress responses, host adaption, and fungal pathogenesis. Emphasis will be given to UPS regulation of pathogenic factors that are important for fungal pathogenesis. We also discuss future potential therapeutic strategies for fungal infections based on targeting UPS pathways.
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Affiliation(s)
- Chengjun Cao
- Public Health Research Institute, Rutgers University, New Brunswick, NJ, United States
| | - Chaoyang Xue
- Public Health Research Institute, Rutgers University, New Brunswick, NJ, United States
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers University, Newark, NJ, United States
- Rutgers Center for Lipid Research, Rutgers University, New Brunswick, NJ, United States
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9
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Li H, Cai Y, Deng Q, Bao H, Chen J, Shen W. Ovarian Tumor Domain-Containing Proteases-Deubiquitylation Enzyme Gene SsCI33130 Involved in the Regulation of Mating/Filamentation and Pathogenicity in Sporisorium scitamineum. Front Microbiol 2021; 12:746550. [PMID: 34675909 PMCID: PMC8523855 DOI: 10.3389/fmicb.2021.746550] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Accepted: 09/09/2021] [Indexed: 11/30/2022] Open
Abstract
Sugarcane is an important sugar crop. Sugarcane smut, caused by Sporisorium scitamineum, is a worldwide sugarcane disease with serious economic losses and lack of effective control measures. Revealing the molecular pathogenesis of S. scitamineum is very helpful to the development of effective prevention and control technology. Deubiquitinase removes ubiquitin molecules from their binding substrates and participates in a variety of physiological activities in eukaryotes. Based on the transcriptome sequencing data of two isolates (Ss16 and Ss47) of S. scitamineum with different pathogenicities, SsCI33130, a gene encoding an OTU1-deubiquitin enzyme, was identified. The positive knockout mutants and complementary mutants of the SsCI33130 gene were successfully obtained through polyethylene glycol-mediated protoplast transformation technology. In order to study the possible function of this gene in pathogenicity, phenotypic comparison of the growth, morphology, abiotic stress, sexual mating, pathogenicity, and gene expression levels of the knockout mutants, complementary mutants, and their wild type strains were conducted. The results demonstrated that the gene had almost no effect on abiotic stress, cell wall integrity, growth, and morphology, but was related to the sexual mating and pathogenicity of S. scitamineum. The sexual mating ability and pathogenicity between the knockout mutants or between the knockout mutant and wild type were more significantly reduced than between the wild types, the complementary mutants, or the wild types and complementary mutants. The sexual mating between the knockout mutants or between the knockout mutant and wild type could be restored by the exogenous addition of small-molecule signaling substances such as 5 mM cyclic adenosine monophosphate (cAMP) or 0.02 mM tryptophol. In addition, during sexual mating, the expression levels of tryptophol and cAMP synthesis-related genes in the knockout mutant combinations were significantly lower than those in the wild type combinations, while the expression levels in the complementary mutant combinations were restored to the level of the wild type. It is speculated that the SsCI33130 gene may be involved in the development of sexual mating and pathogenicity in S. scitamineum by regulating the synthesis of the small-molecule signaling substances (cAMP or tryptophol) required during the sexual mating of S. scitamineum, thereby providing a molecular basis for the study of the pathogenic mechanisms of S. scitamineum.
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Affiliation(s)
- Huizhong Li
- College of Agriculture, South China Agricultural University, Guangzhou, China.,Sugarcane Research Laboratory, South China Agricultural University, Guangzhou, China
| | - Yichang Cai
- College of Agriculture, South China Agricultural University, Guangzhou, China.,Sugarcane Research Laboratory, South China Agricultural University, Guangzhou, China
| | - Quanqing Deng
- College of Agriculture, South China Agricultural University, Guangzhou, China.,Sugarcane Research Laboratory, South China Agricultural University, Guangzhou, China
| | - Han Bao
- College of Agriculture, South China Agricultural University, Guangzhou, China.,Sugarcane Research Laboratory, South China Agricultural University, Guangzhou, China
| | - Jianwen Chen
- College of Agriculture, South China Agricultural University, Guangzhou, China.,Sugarcane Research Laboratory, South China Agricultural University, Guangzhou, China
| | - Wankuan Shen
- College of Agriculture, South China Agricultural University, Guangzhou, China.,Sugarcane Research Laboratory, South China Agricultural University, Guangzhou, China.,Scientific Observing and Experimental Station of Crop Cultivation in South China, Ministry of Agriculture and Rural Affairs, Guangzhou, China
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10
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Gu Z. An improved staining method of cell cycle analysis with Sybr Green I for fungi: Cryptococcus neoformans and Saccharomyces cerevisiae. Cell Cycle 2021; 20:271-282. [PMID: 33463377 PMCID: PMC7889188 DOI: 10.1080/15384101.2020.1870334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 12/13/2020] [Accepted: 12/28/2020] [Indexed: 10/22/2022] Open
Abstract
Cryptococcus neoformans is a pathogenic fungus which causes millions of deaths and infections, especially threatening immunocompromised individuals. During the development of new drugs, the ubiquitination has been found to play an important role in the regulation of the virulence and cell cycle of this fungus. Based on this mechanism, ubiquitination-related mutant strains exhibiting cell cycle arrest have been established for drug development for the fungus. However, flow cytometry detection of the cell cycle in fungi is generally difficult because the thick cell wall and capsule of fungi generally contribute to a nonspecific signal of cytometry. In this study, an improved method, derived from Saccharomyces cerevisiae assays, is developed to specifically stain C. neoformans, in whose cell cycle the G1 and G2 peaks are separated enough to be allowed for cell cycle analysis. As a result, the improved method facilitates the detection of the alterations in the cell cycle of C. neoformans with a mutation that results in cell cycle arrest, which distinctly delays the cell division of C. neoformans. Thus, the improved method reported here provides detailed technical information regarding assays on C. neoformans and, more importantly, offers a solution for assessing the cell cycle in other fungi in the future. Abbreviation: PI: propidium iodide.
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Affiliation(s)
- Zhongkai Gu
- Institutes of Biomedical Sciences, Fudan University, Shanghai, People’s Republic of China
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11
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Roth C, Murray D, Scott A, Fu C, Averette AF, Sun S, Heitman J, Magwene PM. Pleiotropy and epistasis within and between signaling pathways defines the genetic architecture of fungal virulence. PLoS Genet 2021; 17:e1009313. [PMID: 33493169 PMCID: PMC7861560 DOI: 10.1371/journal.pgen.1009313] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Revised: 02/04/2021] [Accepted: 12/17/2020] [Indexed: 01/11/2023] Open
Abstract
Cryptococcal disease is estimated to affect nearly a quarter of a million people annually. Environmental isolates of Cryptococcus deneoformans, which make up 15 to 30% of clinical infections in temperate climates such as Europe, vary in their pathogenicity, ranging from benign to hyper-virulent. Key traits that contribute to virulence, such as the production of the pigment melanin, an extracellular polysaccharide capsule, and the ability to grow at human body temperature have been identified, yet little is known about the genetic basis of variation in such traits. Here we investigate the genetic basis of melanization, capsule size, thermal tolerance, oxidative stress resistance, and antifungal drug sensitivity using quantitative trait locus (QTL) mapping in progeny derived from a cross between two divergent C. deneoformans strains. Using a "function-valued" QTL analysis framework that exploits both time-series information and growth differences across multiple environments, we identified QTL for each of these virulence traits and drug susceptibility. For three QTL we identified the underlying genes and nucleotide differences that govern variation in virulence traits. One of these genes, RIC8, which encodes a regulator of cAMP-PKA signaling, contributes to variation in four virulence traits: melanization, capsule size, thermal tolerance, and resistance to oxidative stress. Two major effect QTL for amphotericin B resistance map to the genes SSK1 and SSK2, which encode key components of the HOG pathway, a fungal-specific signal transduction network that orchestrates cellular responses to osmotic and other stresses. We also discovered complex epistatic interactions within and between genes in the HOG and cAMP-PKA pathways that regulate antifungal drug resistance and resistance to oxidative stress. Our findings advance the understanding of virulence traits among diverse lineages of Cryptococcus, and highlight the role of genetic variation in key stress-responsive signaling pathways as a major contributor to phenotypic variation.
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Affiliation(s)
- Cullen Roth
- Department of Biology, Duke University, Durham, North Carolina, United States of America
- University Program in Genetics and Genomics, Duke University, Durham, North Carolina, United States of America
| | - Debra Murray
- Department of Biology, Duke University, Durham, North Carolina, United States of America
| | - Alexandria Scott
- Department of Biology, Duke University, Durham, North Carolina, United States of America
| | - Ci Fu
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Anna F. Averette
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Sheng Sun
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Joseph Heitman
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Paul M. Magwene
- Department of Biology, Duke University, Durham, North Carolina, United States of America
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12
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Zhao J, Yang Y, Fan Y, Yi J, Zhang C, Gu Z, Pan W, Gu J, Liao W, Fang W. Ribosomal Protein L40e Fused With a Ubiquitin Moiety Is Essential for the Vegetative Growth, Morphological Homeostasis, Cell Cycle Progression, and Pathogenicity of Cryptococcus neoformans. Front Microbiol 2020; 11:570269. [PMID: 33224112 PMCID: PMC7674629 DOI: 10.3389/fmicb.2020.570269] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Accepted: 08/20/2020] [Indexed: 11/13/2022] Open
Abstract
Ubiquitin is a highly conserved protein required for various fundamental cellular processes in eukaryotes. Herein, we first report the contribution of the ubiquitin fusion protein Ubi1 (a ubiquitin monomer fused with the ribosome protein L40e, Rpl40e) in the growth and pathogenicity of Cryptococcus neoformans. UBI1 deletion resulted in severe growth restriction of C. neoformans, whose growth rate was positively correlated with UBI1 expression level. The growth defect of the ubi1Δ strain could be closely associated with its morphological abnormalities, such as its reduced ribosome particles. In addition, the ubi1Δ mutant also displayed increased cell ploidy, cell cycle arrest, and decreased intracellular survival inside macrophages. All these phenotypes were reversed by the reconstitution of the full-length UBI1 gene or RPL40a domain. Mouse survival and fungal burden assays further revealed a severely attenuated pathogenicity for the ubi1Δ mutant, which is probably associated with its reduced stress tolerance and the induction of T-helper 1-type immune response. Taken together, Ubi1 is required for maintaining the vegetative growth, morphological homeostasis, cell cycle progression, and pathogenicity in vivo of C. neoformans. The pleiotropic roles of Ubi1 are dependent on the presence of Rpl40e and associated with its regulation of cryptococcal ribosome biogenesis.
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Affiliation(s)
- Jingyu Zhao
- Shanghai Key Laboratory of Molecular Medical Mycology, Department of Dermatology, Changzheng Hospital, Second Military Medical University, Shanghai, China.,Department of Dermatology, Shanghai Eastern Hepatobiliary Surgery Hospital, Shanghai, China
| | - Yali Yang
- Shanghai Key Laboratory of Molecular Medical Mycology, Department of Dermatology, Changzheng Hospital, Second Military Medical University, Shanghai, China.,Department of Dermatology, Shanghai Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yibin Fan
- Department of Dermatology, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, China
| | - Jiu Yi
- Shanghai Key Laboratory of Molecular Medical Mycology, Department of Dermatology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Chao Zhang
- Shanghai Key Laboratory of Molecular Medical Mycology, Department of Dermatology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Zhongkai Gu
- The Institute of Biomedical Sciences, Fudan University, Shanghai, China
| | - Weihua Pan
- Shanghai Key Laboratory of Molecular Medical Mycology, Department of Dermatology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Julin Gu
- Department of Dermatology, Shanghai Eastern Hepatobiliary Surgery Hospital, Shanghai, China
| | - Wanqing Liao
- Shanghai Key Laboratory of Molecular Medical Mycology, Department of Dermatology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Wei Fang
- Shanghai Key Laboratory of Molecular Medical Mycology, Department of Dermatology, Changzheng Hospital, Second Military Medical University, Shanghai, China
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13
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Yi J, Sang J, Zhao J, Gao L, Yang Y, Yan L, Zhang C, Pan W, Wang G, Liao W. Transcription factor Liv4 is required for growth and pathogenesis of Cryptococcus neoformans. FEMS Yeast Res 2020; 20:foaa015. [PMID: 32391887 DOI: 10.1093/femsyr/foaa015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 04/03/2020] [Indexed: 11/13/2022] Open
Abstract
Cryptococcus neoformans is an important invasive fungal pathogen that causes life-threatening meningoencephalitis in humans. Its biological and pathogenic regulatory mechanisms remain largely unknown, particularly due to the presence of those core transcription factors (TFs). Here, we conducted a detailed characterization of the TF Liv4 in the biology and virulence of C. neoformans. Deletion of TF Liv4 protein resulted in growth defect under both normal and stress conditions (such as high temperature and cell wall/membrane damaging agents), drastic morphological damage and also attenuated virulence in C. neoformans. These phenotypic changes might be contributed to transcriptional abnormality in the liv4Δ mutant, in which several cryptococcal genes involved in energy metabolism and cell wall integrity were downregulated. Furthermore, ChIP-seq and ChIP-qPCR assays suggested TF Liv4 might exert its regulatory function in transcription by its activation of RBP1 in C. neoformans. Taken together, our work highlights the importance of TF Liv4 in the growth and virulence of C. neoformans, and it facilitates a better understanding of cryptococcal pathogenesis mechanisms.
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Affiliation(s)
- Jiu Yi
- Department of Dermatology, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China
- Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China
| | - Junjun Sang
- Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China
- Department of Dermatology, 900 Hospital of the Joint Logistics Team, Fuzhou, Fujian Province, 350025, China
| | - Jingyu Zhao
- Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China
- Department of Dermatology, Shanghai Eastern Hepatobiliary Surgery Hospital, Shanghai, 201805, China
| | - Lei Gao
- Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China
| | - Yali Yang
- Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China
| | - Lei Yan
- Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China
| | - Chao Zhang
- Department of Dermatology, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China
- Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China
| | - Weihua Pan
- Department of Dermatology, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China
- Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China
| | - Guizhen Wang
- Emergency room, Shanghai Tenth People's Hospital of Tongji University, 200072, Shanghai, China
| | - Wanqing Liao
- Department of Dermatology, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China
- Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China
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14
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Que Y, Xu Z, Wang C, Lv W, Yue X, Xu L, Tang S, Dai H, Wang Z. The putative deubiquitinating enzyme MoUbp4 is required for infection-related morphogenesis and pathogenicity in the rice blast fungus Magnaporthe oryzae. Curr Genet 2019; 66:561-576. [PMID: 31872271 DOI: 10.1007/s00294-019-01049-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 12/09/2019] [Accepted: 12/10/2019] [Indexed: 11/28/2022]
Abstract
Ubiquitination is a key regulatory mechanism that affects numerous important biological processes, including cellular differentiation and pathogenesis in eukaryotic cells. Attachment of proteins to ubiquitin is reversed by specialized proteases, deubiquitinating enzymes (DUBs), which are essential for precursor processing, maintaining ubiquitin homeostasis and promoting protein degradation by recycling ubiquitins. Here, we report the identification of a novel non-pathogenic T-DNA-tagged mutant T612 of Magnaporthe oryzae with a single insertion in the second exon of MoUBP4, which encodes a putative ubiquitin carboxyl-terminal hydrolase. Targeted gene deletion mutants of MoUBP4 are significantly reduced in mycelial growth, conidiation, and increased in tolerance to SDS and CR (Congo red) cell-wall damage. The ΔMoubp4 mutants are blocked in penetration and invasive growth, which results in the loss of pathogenicity. Many conidia produced by the ΔMoubp4 mutants are unable to form appressoria and mobilization and degradation of glycogen and lipid droplets are significantly delayed. Moreover, immunohybridization analysis revealed that total protein ubiquitination levels of the null mutants were significantly increased, indicating that MoUbp4 functions as a deubiquitination enzyme. Taken together, we conclude that MoUbp4 is required for deubiquitination, infection-related morphogenesis and pathogenicity in M. oryzae.
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Affiliation(s)
- Yawei Que
- State Key Laboratory for Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, People's Republic of China
| | - Zhe Xu
- State Key Laboratory for Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, People's Republic of China
| | - Chunyan Wang
- State Key Laboratory for Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, People's Republic of China
| | - Wuyun Lv
- State Key Laboratory for Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, People's Republic of China
| | - Xiaofeng Yue
- State Key Laboratory for Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, People's Republic of China
| | - Lin Xu
- State Key Laboratory for Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, People's Republic of China
| | - Shuai Tang
- State Key Laboratory for Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, People's Republic of China
| | - Han Dai
- State Key Laboratory for Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, People's Republic of China
| | - Zhengyi Wang
- State Key Laboratory for Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, People's Republic of China.
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15
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Rahim K, Huo L, Li C, Zhang P, Basit A, Xiang B, Ting B, Hao X, Zhu X. Identification of a basidiomycete-specific Vilse-like GTPase activating proteins (GAPs) and its roles in the production of virulence factors in Cryptococcus neoformans. FEMS Yeast Res 2019; 17:4644832. [PMID: 29177429 DOI: 10.1093/femsyr/fox089] [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: 08/16/2017] [Accepted: 11/20/2017] [Indexed: 12/25/2022] Open
Abstract
Cryptococcus neoformans is a basidiomycetous pathogenic yeast that causes fatal infections in both immunocompetent and immunocompromised patients. Regulation on the production of its virulence factors is not fully understood. Here we reported the characterization of a gene, named CVH1(CNA06260), encoding a Drosophila Vilse-like RhoGAP homolog, which is hallmarked by three conserved functional domains: WW, MyTH4 and RhoGAP. Phylogenetic analysis suggests that CVH1 is highly conserved from protists to mammals and interestingly in basidiomycetes, but absent in plants or Ascomycota and other lower fungi. This phylogenetic distribution indicates an evolutionary link among these groups of organisms. Functional analyses demonstrated that CVH1 was involved in stress tolerance and virulence factor production. By disrupting CVH1, we created a second mutant cvh1Δ with the CRISPR-Cas9 editing tool. The mutant strain exhibited hypersensitivity to osmotic stress by 2 M sorbitol and NaCl, suggesting defects in the HOG signaling pathway and an interaction of Cvh1 with the HOG pathway. Hypersensitivity of cvh1Δ to 1% Congo red and 0.01% SDS suggests that the cell wall integrity was impaired in the mutant. And cvh1Δ hardly produced the pigment melanin and capsule. Our study for the first time demonstrates that the fungal Vilse-like RhoGAP CVH1 is an important regulator of multiple biological processes in C. neoformans, and provides novel insights into the regulatory circuit of stress resistance/cell wall integrity, and laccase and capsule synthesis in C. neoformans.
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Affiliation(s)
- Kashif Rahim
- Beijing Key Laboratory of Genetic Engineering Drug and Biotechnology, Institute of Biochemistry and Biotechnology, College of Life Sciences, Beijing Normal University, Beijing 100875, China
| | - Liang Huo
- Beijing Key Laboratory of Genetic Engineering Drug and Biotechnology, Institute of Biochemistry and Biotechnology, College of Life Sciences, Beijing Normal University, Beijing 100875, China
| | - Chenxi Li
- Beijing Key Laboratory of Genetic Engineering Drug and Biotechnology, Institute of Biochemistry and Biotechnology, College of Life Sciences, Beijing Normal University, Beijing 100875, China
| | - Ping Zhang
- Beijing Key Laboratory of Genetic Engineering Drug and Biotechnology, Institute of Biochemistry and Biotechnology, College of Life Sciences, Beijing Normal University, Beijing 100875, China
| | - Abdul Basit
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Biyun Xiang
- Beijing Key Laboratory of Genetic Engineering Drug and Biotechnology, Institute of Biochemistry and Biotechnology, College of Life Sciences, Beijing Normal University, Beijing 100875, China
| | - Bie Ting
- Beijing Key Laboratory of Genetic Engineering Drug and Biotechnology, Institute of Biochemistry and Biotechnology, College of Life Sciences, Beijing Normal University, Beijing 100875, China
| | - Xiaoran Hao
- Beijing Key Laboratory of Genetic Engineering Drug and Biotechnology, Institute of Biochemistry and Biotechnology, College of Life Sciences, Beijing Normal University, Beijing 100875, China
| | - Xudong Zhu
- Beijing Key Laboratory of Genetic Engineering Drug and Biotechnology, Institute of Biochemistry and Biotechnology, College of Life Sciences, Beijing Normal University, Beijing 100875, China
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16
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Wang Z, Zhang H, Liu C, Xing J, Chen XL. A Deubiquitinating Enzyme Ubp14 Is Required for Development, Stress Response, Nutrient Utilization, and Pathogenesis of Magnaporthe oryzae. Front Microbiol 2018; 9:769. [PMID: 29720973 PMCID: PMC5915541 DOI: 10.3389/fmicb.2018.00769] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Accepted: 04/04/2018] [Indexed: 02/02/2023] Open
Abstract
Ubiquitination is an essential protein modification in eukaryotic cells, which is reversible. Deubiquitinating enzymes (DUBs) catalyze deubiquitination process to reverse ubiquitination, maintain ubiquitin homeostasis or promote protein degradation by recycling ubiquitins. In order to investigate effects of deubiquitination process in plant pathogenic fungus Magnaporthe oryzae, we generated deletion mutants of MoUBP14. Ortholog of MoUbp14 was reported to play general roles in ubiquitin-mediated protein degradation in Saccharomyces cerevisiae. The ΔMoubp14 mutant lost its pathogenicity and was severely reduced in mycelial growth, sporulation, carbon source utilization, and increased in sensitivity to distinct stresses. The mutant was blocked in penetration, which could due to defect in turgor generation. It is also blocked in invasive growth, which could due to reduction in stress tolerance and nutrient utilization. Deletion of UBP14 also led to accumulation of free polyubiquitin chains. Pulldown assay identified some proteins related to carbohydrate metabolism and stress response may putatively interact with MoUbp14, including two key rate-limiting enzymes of gluconeogenesis, MoFbp1 and MoPck1. These two proteins were degraded when the glucose was supplied to M. oryzae grown in low glucose media for a short period of time (∼12 h), and this process required MoUbp14. In summary, pleiotropic phenotypes of the deletion mutants indicated that MoUbp14 is required for different developments and pathogenicity of M. oryzae.
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Affiliation(s)
- Zhao Wang
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Hong Zhang
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Caiyun Liu
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Junjie Xing
- State Key Laboratory of Hybrid Rice, Hunan Hybrid Rice Research Center, Changsha, China
| | - Xiao-Lin Chen
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China.,State Key Laboratory of Hybrid Rice, Hunan Hybrid Rice Research Center, Changsha, China
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17
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Bouklas T, Masone L, Fries BC. Differences in Sirtuin Regulation in Response to Calorie Restriction in Cryptococcus neoformans. J Fungi (Basel) 2018; 4:E26. [PMID: 29463010 PMCID: PMC5872329 DOI: 10.3390/jof4010026] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 02/15/2018] [Accepted: 02/16/2018] [Indexed: 12/17/2022] Open
Abstract
Cryptococcus neoformans successfully replicates in low glucose in infected patients. In the serotype A strain, H99, growth in this condition prolongs lifespan regulated by SIR2, and can be modulated with SIR2-specific drugs. Previous studies show that lifespan modulation of a cryptococcal population affects its sensitivity to antifungals, and survival in an infection model. Sirtuins and their role in longevity are conserved among fungi; however, the effect of glucose starvation is not confirmed even in Saccharomyces cerevisiae. Lifespan analysis of C. neoformans strains in low glucose showed that 37.5% exhibited pro-longevity, and lifespan of a serotype D strain, RC2, was shortened. Transcriptome comparison of H99 and RC2 under calorie restriction demonstrated differences, confirmed by real-time PCR showing that SIR2, TOR1, SCH9, and PKA1 expression correlated with lifespan response to calorie restriction. As expected, RC2-sir2Δ cells exhibited a shortened lifespan, which was reconstituted. However, shortened lifespan from calorie restriction was independent of SIR2. In contrast to H99 but consistent with altered SIR2 regulation, SIR2-specific drugs did not affect outcome of RC2 infection. These data suggest that SIR2 regulation and response to calorie restriction varies in C. neoformans, which should be considered when Sirtuins are investigated as potential therapy targets for fungal infections.
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Affiliation(s)
- Tejas Bouklas
- Department of Biomedical Sciences, Long Island University-Post, Brookville, NY 11548, USA.
| | - Lindsey Masone
- Department of Biomedical Sciences, Long Island University-Post, Brookville, NY 11548, USA.
| | - Bettina C Fries
- Department of Medicine (Division of Infectious Diseases) and Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY 11794 USA.
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18
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Fan Y, Tao X, Pan W, Fang W, Huang Y, Jia M. CSN1201, a subunit of the COP9 signalosome, regulates the virulence in Cryptococcus neoformans infection. Fungal Genet Biol 2016:S1087-1845(16)30144-X. [PMID: 27915049 DOI: 10.1016/j.fgb.2016.11.008] [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: 08/08/2016] [Revised: 10/12/2016] [Accepted: 11/29/2016] [Indexed: 10/20/2022]
Abstract
The COP9 signalosome (CSN) is a multisubunit protein complex, and it now has been found to participate in diverse cellular and developmental processes in various eukaryotic organisms. Cryptococcus neoformans (C. neoformans) is an important basidiomycete pathogen that causes life-threatening meningoencephalitis primarily in the immune compromised population. Here, we generated CSN deletion mutants to investigate the role in Cryptococcus infection. Compared to other CSN mutants, we identified a CSN1201 mutant exhibited severely attenuated virulence. Deletion of CSN1201 made cryptococcal cells more susceptible to nearly all in vitro stresses. Furthermore, deletion of CSN1201 obviously impaired survival of C. neoformans. At the same time, in vivo virulence assay of mouse infection models demonstrated that CSN1201 significantly enhanced the virulence of C. neoformans compared with the other CSN subunit strains, while ELISA analysis of C. neoformans infection in innate or adaptive immune response showed that deletion of CSN1201 significantly impaired cytokines and interferon expression. In vitro model of the blood-brain barrier (BBB) analysis indicated that deletion of CSN1201 reduced the invasion efficacy of Cryptococcusto cross BBB. Taken together, our findings reveal a novel mechanism of CSN1201, which plays a critical role for the virulence composite of C. neoformans, and also provides an additional yeast survival and propagation advantage in the host.
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Affiliation(s)
- Yibin Fan
- Department of Dermatology, Zhejiang Provincial People's Hospital, No. 158 Shangtang Road, Hangzhou 310014, Zhejiang, PR China.
| | - Xiaohua Tao
- Department of Dermatology, Zhejiang Provincial People's Hospital, No. 158 Shangtang Road, Hangzhou 310014, Zhejiang, PR China
| | - Weili Pan
- Department of Dermatology, Zhejiang Provincial People's Hospital, No. 158 Shangtang Road, Hangzhou 310014, Zhejiang, PR China
| | - Wei Fang
- Department of Dermatology, Zhejiang Provincial People's Hospital, No. 158 Shangtang Road, Hangzhou 310014, Zhejiang, PR China
| | - Youming Huang
- Department of Dermatology, Zhejiang Provincial People's Hospital, No. 158 Shangtang Road, Hangzhou 310014, Zhejiang, PR China
| | - Mingyan Jia
- Department of Dermatology, Cixi People's Hospital, No. 999 South East Road, Cixi 315300 Zhejiang, PR China
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19
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Unique roles of the unfolded protein response pathway in fungal development and differentiation. Sci Rep 2016; 6:33413. [PMID: 27629591 PMCID: PMC5024300 DOI: 10.1038/srep33413] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 07/11/2016] [Indexed: 01/05/2023] Open
Abstract
Cryptococcus neoformans, a global fungal meningitis pathogen, employs the unfolded protein response pathway. This pathway, which consists of an evolutionarily conserved Ire1 kinase/endoribonuclease and a unique transcription factor (Hxl1), modulates the endoplasmic reticulum stress response and pathogenicity. Here, we report that the unfolded protein response pathway governs sexual and unisexual differentiation of C. neoformans in an Ire1-dependent but Hxl1-independent manner. The ire1∆ mutants showed defects in sexual mating, with reduced cell fusion and pheromone-mediated formation of the conjugation tube. Unexpectedly, these mating defects did not result from defective pheromone production because expression of the mating pheromone gene (MFα1) was strongly induced in the ire1∆ mutant. Ire1 controls sexual differentiation by modulating the function of the molecular chaperone Kar2 and by regulating mating-induced localisation of mating pheromone transporter (Ste6) and receptor (Ste3/Cprα). Deletion of IRE1, but not HXL1, also caused significant defects in unisexual differentiation in a Kar2-independent manner. Moreover, we showed that Rim101 is a novel downstream factor of Ire1 for production of the capsule, which is a unique structural determinant of C. neoformans virulence. Therefore, Ire1 uniquely regulates fungal development and differentiation in an Hxl1-independent manner.
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20
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Meng Y, Zhang C, Yi J, Zhou Z, Fa Z, Zhao J, Yang Y, Fang W, Wang Y, Liao WQ. Deubiquitinase Ubp5 Is Required for the Growth and Pathogenicity of Cryptococcus gattii. PLoS One 2016; 11:e0153219. [PMID: 27049762 PMCID: PMC4822882 DOI: 10.1371/journal.pone.0153219] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 03/24/2016] [Indexed: 12/19/2022] Open
Abstract
Cryptococcus gattii is a resurgent fungal pathogen that primarily infects immunocompetent hosts. Thus, it poses an increasingly significant impact on global public health; however, the mechanisms underlying its pathogenesis remain largely unknown. We conducted a detailed characterization of the deubiquitinase Ubp5 in the biology and virulence of C. gattii using the hypervirulent strain R265, and defined its properties as either distinctive or shared with C. neoformans. Deletion of the C. gattii Ubp5 protein by site-directed disruption resulted in a severe growth defect under both normal and stressful conditions (such as high temperature, high salt, cell wall damaging agents, and antifungal agents), similar to the effects observed in C. neoformans. However, unlike C. neoformans, the C. gattii ubp5Δ mutant displayed a slight enhancement of capsule and melanin production, indicating the evolutionary convergence and divergence of Ubp5 between these two sibling species. Attenuated virulence of the Cg-ubp5Δ mutant was not solely due to its reduced thermotolerance at 37°C, as shown in both worm and mouse survival assays. In addition, the assessment of fungal burden in mammalian organs further indicated that Ubp5 was required for C. gattii pulmonary survival and, consequently, extrapulmonary dissemination. Taken together, our work highlights the importance of deubiquitinase Ubp5 in the virulence composite of both pathogenic cryptococcal species, and it facilitates a better understanding of C. gattii virulence mechanisms.
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Affiliation(s)
- Yunfang Meng
- Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Second Military Medical University, Shanghai, China.,Department of Dermatology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong, China
| | - Chao Zhang
- PLA Key Laboratory of Mycosis, Department of Dermatology and Venereology, Changzheng Hospital, Shanghai, China
| | - Jiu Yi
- PLA Key Laboratory of Mycosis, Department of Dermatology and Venereology, Changzheng Hospital, Shanghai, China
| | - Zhaojing Zhou
- PLA Key Laboratory of Mycosis, Department of Dermatology and Venereology, Changzheng Hospital, Shanghai, China
| | - Zhenzong Fa
- PLA Key Laboratory of Mycosis, Department of Dermatology and Venereology, Changzheng Hospital, Shanghai, China
| | - Jingyu Zhao
- Shanghai Dermatology Hospital, Shanghai, China
| | - Yali Yang
- PLA Key Laboratory of Mycosis, Department of Dermatology and Venereology, Changzheng Hospital, Shanghai, China
| | - Wei Fang
- PLA Key Laboratory of Mycosis, Department of Dermatology and Venereology, Changzheng Hospital, Shanghai, China
| | - Yan Wang
- Department of Pharmacology, School of Pharmacy, Second Military Medical University, Shanghai, China
| | - Wan-Qing Liao
- Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Second Military Medical University, Shanghai, China
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Chen M, Xing Y, Lu A, Fang W, Sun B, Chen C, Liao W, Meng G. Internalized Cryptococcus neoformans Activates the Canonical Caspase-1 and the Noncanonical Caspase-8 Inflammasomes. THE JOURNAL OF IMMUNOLOGY 2015; 195:4962-72. [PMID: 26466953 DOI: 10.4049/jimmunol.1500865] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 09/18/2015] [Indexed: 12/15/2022]
Abstract
Cryptococcus neoformans is an opportunistic fungal pathogen that causes cryptococcosis in immunocompromised patients as well as immunocompetent individuals. Host cell surface receptors that recognize C. neoformans have been widely studied. However, intracellular sensing of this pathogen is still poorly understood. Our previous studies have demonstrated that both biofilm and acapsular mutant of C. neoformans are able to activate the NOD-like receptor family, pyrin domain-containing 3 (NLRP3) inflammasome. In the current study, it was found that opsonization-mediated internalization of encapsulated C. neoformans also activated the canonical NLRP3-apoptosis-associated speck-like protein containing a CARD (ASC)-caspase-1 inflammasome. In addition, the internalized C. neoformans activated the noncanonical NLRP3-ASC-caspase-8 inflammasome as well, which resulted in robust IL-1β secretion and cell death from caspase-1-deficient primary dendritic cells. Interestingly, we found that caspase-1 was inhibitory for the activation of caspase-8 in dendritic cells upon C. neorformans challenge. Further mechanistic studies showed that both phagolysosome membrane permeabilization and potassium efflux were responsible for C. neoformans-induced activation of either the canonical NLRP3-ASC-caspase-1 inflammasome or the noncanonical NLRP3-ASC-caspase-8 inflammasome. Moreover, challenge with zymosan also led to the activation of the noncanonical NLRP3-ASC-caspase-8 inflammasome in cells absent for caspase-1. Collectively, these findings uncover a number of novel signaling pathways for the innate immune response of host cells to C. neoformans infection and suggest that manipulating NLRP3 signaling may help to control fungal challenge.
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Affiliation(s)
- Mingkuan Chen
- Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China; and
| | - Yue Xing
- Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China; and
| | - Ailing Lu
- Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China; and
| | - Wei Fang
- Shanghai Key Laboratory of Molecular Medical Mycology, Changzheng Hospital, Shanghai 200003, China
| | - Bing Sun
- Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China; and
| | - Changbin Chen
- Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China; and
| | - Wanqing Liao
- Shanghai Key Laboratory of Molecular Medical Mycology, Changzheng Hospital, Shanghai 200003, China
| | - Guangxun Meng
- Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China; and
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Hu G, Caza M, Cadieux B, Bakkeren E, Do E, Jung WH, Kronstad JW. The endosomal sorting complex required for transport machinery influences haem uptake and capsule elaboration in Cryptococcus neoformans. Mol Microbiol 2015; 96:973-92. [PMID: 25732100 DOI: 10.1111/mmi.12985] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/25/2015] [Indexed: 11/29/2022]
Abstract
Iron availability is a key determinant of virulence in the pathogenic fungus Cryptococcus neoformans. Previous work revealed that the ESCRT (endosomal sorting complex required for transport) protein Vps23 functions in iron acquisition, capsule formation and virulence. Here, we further characterized the ESCRT machinery to demonstrate that defects in the ESCRT-II and III complexes caused reduced capsule attachment, impaired growth on haem and resistance to non-iron metalloprotoporphyrins. The ESCRT mutants shared several phenotypes with a mutant lacking the pH-response regulator Rim101, and in other fungi, the ESCRT machinery is known to activate Rim101 via proteolytic cleavage. We therefore expressed a truncated and activated version of Rim101 in the ESCRT mutants and found that this allele restored capsule formation but not growth on haem, thus suggesting a Rim101-independent contribution to haem uptake. We also demonstrated that the ESCRT machinery acts downstream of the cAMP/protein kinase A pathway to influence capsule elaboration. Defects in the ESCRT components also attenuated virulence in macrophage survival assays and a mouse model of cryptococcosis to a greater extent than reported for loss of Rim101. Overall, these results indicate that the ESCRT complexes function in capsule elaboration, haem uptake and virulence via Rim101-dependent and independent mechanisms.
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Affiliation(s)
- Guanggan Hu
- Michael Smith Laboratories, The University of British Columbia, 2185 East Mall, Vancouver, BC, V6T 1Z4, Canada
| | - Mélissa Caza
- Michael Smith Laboratories, The University of British Columbia, 2185 East Mall, Vancouver, BC, V6T 1Z4, Canada
| | - Brigitte Cadieux
- Michael Smith Laboratories, The University of British Columbia, 2185 East Mall, Vancouver, BC, V6T 1Z4, Canada
| | - Erik Bakkeren
- Michael Smith Laboratories, The University of British Columbia, 2185 East Mall, Vancouver, BC, V6T 1Z4, Canada
| | - Eunsoo Do
- Department of Systems Biotechnology, Chung-Ang University, Anseong, 456-756, Republic of Korea
| | - Won Hee Jung
- Department of Systems Biotechnology, Chung-Ang University, Anseong, 456-756, Republic of Korea
| | - James W Kronstad
- Michael Smith Laboratories, The University of British Columbia, 2185 East Mall, Vancouver, BC, V6T 1Z4, Canada
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Acapsular Cryptococcus neoformans activates the NLRP3 inflammasome. Microbes Infect 2014; 16:845-54. [PMID: 25193031 DOI: 10.1016/j.micinf.2014.08.013] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2014] [Revised: 07/17/2014] [Accepted: 08/25/2014] [Indexed: 01/24/2023]
Abstract
Cryptococcus neoformans (C. neoformans) is an opportunistic fungal pathogen that mainly infects immunocompromised individuals such as AIDS patients. Although cell surface receptors for recognition of C. neoformans have been studies intensively, cytoplasmic recognition of this pathogen remains unclear. As an important detector of pathogen infection, inflammasome can sense and get activated by infection of various pathogens, including pathogenic fungi such as Candida albicans and Aspergillus fumigatus. Our present study showed that acapsular C. neoformans (cap59Δ) activated the NLRP3-, but not AIM2-nor NLRC4- inflammasome. During this process, viability of the fungus was required. Moreover, our in vivo results showed that during the pulmonary infection of cap59Δ, immune cell infiltration into the lung and effective clearance of the fungus were both dependent on the presence of NLRP3 inflammasome. In summary, our data suggest that the capsule of C. neoformans prevents recognition of the fungus by host NLRP3 inflammasome and indicate that manipulation of inflammasome activity maybe a novel approach to control C. neoformans infection.
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Kim Y, Jo H, Lim CJ. Deubiquitinating activity of Sdu1, a putative member of the PPPDE peptidase family, in Schizosaccharomyces pombe. Can J Microbiol 2013; 59:789-96. [DOI: 10.1139/cjm-2013-0453] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The Schizosaccharomyces pombe sdu+ gene encoding a putative member of the PPPDE (Permuted Papain fold Peptidases of DsRNA viruses and Eukaryotes) superfamily was cloned into an Escherichia coli – yeast shuttle vector pRS316, resulting in the recombinant plasmid pYSTP. The determined nucleotide sequence carries 1207 bp, which would encode a protein of 201 amino acid residues. The S. pombe cells harboring pYSTP contained higher sdu1+ mRNA and deubiquitinating activity levels than the vector control cells, indicating that the sdu1+ gene is functioning. They exhibited a better growth in normal rich medium than the vector control cells. When shifted into the fresh medium containing hydrogen peroxide, menadione, or sodium nitroprusside, the S. pombe cells harboring pYSTP were able to grow reasonably well, while the growth of the vector control cells was arrested. The reactive oxygen species and total glutathione levels of the S. pombe cells harboring pYSTP were lower and higher than those of the vector control cells under the same stressful conditions, respectively. They exhibited a lower nitric oxide level than the vector control cells when subjected to sodium nitroprusside. Taken together, the sdu1+ gene encodes an actual protein having deubiquitinating activity and is involved in the response against oxidative and nitrosative stresses in S. pombe.
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Affiliation(s)
- Yunsik Kim
- Department of Biochemistry, College of Natural Sciences, Kangwon National University, 192-1 Hyoja-2-dong, Chuncheon 200-701, Korea
| | - Hannah Jo
- Department of Biochemistry, College of Natural Sciences, Kangwon National University, 192-1 Hyoja-2-dong, Chuncheon 200-701, Korea
| | - Chang-Jin Lim
- Department of Biochemistry, College of Natural Sciences, Kangwon National University, 192-1 Hyoja-2-dong, Chuncheon 200-701, Korea
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Nanduri B, Suvarnapunya AE, Venkatesan M, Edelmann MJ. Deubiquitinating enzymes as promising drug targets for infectious diseases. Curr Pharm Des 2013; 19:3234-47. [PMID: 23151130 DOI: 10.2174/1381612811319180008] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Accepted: 11/01/2012] [Indexed: 01/25/2023]
Abstract
Deubiquitinating enzymes (DUBs) remove ubiquitin and ubiquitin-like modifications from proteins and they have been known to contribute to processes relevant in microbial infection, such as immune responses pathways. Numerous viral and bacterial DUBs have been identified, and activities of several host DUBs are known to be modulated during the infection process, either by a pathogen or by a host. Recently there have been attempts to take advantage of this feature and design therapeutic inhibitors of DUBs that can be used to limit the spread of infection. This review is focused on exploring the potential of DUBs in the treatment of infectious diseases.
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Affiliation(s)
- Bindu Nanduri
- Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Mississippi State, MS 39762, USA
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