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Wang FH, Wang BB, Gao J, Yang XJ, Jia YB, Tian SY, Li X, Zhang N, Zhang XC, Wei YM, Zhang J, Cai KZ. Determination of cyclic adenosine phosphate and protein content in dormant chlamydospore and nondormant chlamydospore of Arthrobotrys flagrans. J Basic Microbiol 2024; 64:e2400008. [PMID: 38548685 DOI: 10.1002/jobm.202400008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2024] [Revised: 02/24/2024] [Accepted: 03/02/2024] [Indexed: 07/04/2024]
Abstract
Arthrobotrys flagrans, a nematode-eating fungus, is an effective component of animal parasitic nematode biocontrol agents. In the dried formulation, the majority of spores are in an endogenous dormant state. This study focuses on dormant chlamydospore and nondormant chlamydospore of A. flagrans to investigate the differences in cyclic adenosine monophosphate (cAMP) and protein content between the two types of spores. cAMP and soluble proteins were extracted from the nondormant chlamydospore and dormant chlamydospore of two isolates of A. flagrans. The cAMP Direct Immunoassay Kit and Bradford protein concentration assay kit (Coomassie brilliant blue method) were used to detect the cAMP and protein content in two types of spores. Results showed that the content of cAMP in dormant spores of both isolates was significantly higher than that in nondormant spores (p < 0.05). The protein content of dormant spores in DH055 bacteria was significantly higher than that of nondormant spores (p < 0.05). In addition, the protein content of dormant spores of the SDH035 strain was slightly higher than that of nondormant spores, but the difference was not significant (p > 0.05). The results obtained in this study provide evidence for the biochemical mechanism of chlamydospore dormancy or the germination of the nematophagous fungus A. flagrans.
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Affiliation(s)
- Feng-Hui Wang
- College of Veterinary Medicine, Gansu Agricultural University, Lanzhou, China
- Department of Medical college, Medical College of Yan'an University, Yan'an, China
| | - Bo-Bo Wang
- Department of Medical college, Medical College of Yan'an University, Yan'an, China
- Yan'an Key Laboratory of Zoonotic Parasitology Laboratory, Yan'an, China
| | | | - Xiao-Jun Yang
- School of Chemistry and Chemical Engineering, Yan'an University, Yan'an, China
| | - Yi-Bo Jia
- Department of Medical college, Medical College of Yan'an University, Yan'an, China
| | - Shu-Yue Tian
- Department of Medical college, Medical College of Yan'an University, Yan'an, China
| | - Xin Li
- Department of Medical college, Medical College of Yan'an University, Yan'an, China
| | - Nan Zhang
- Key Laboratory of Zoonosis Research by Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Xi-Chen Zhang
- Key Laboratory of Zoonosis Research by Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Yan-Ming Wei
- College of Veterinary Medicine, Gansu Agricultural University, Lanzhou, China
| | - Jing Zhang
- Department of Medical college, Medical College of Yan'an University, Yan'an, China
| | - Kui-Zheng Cai
- Department of Medical college, Medical College of Yan'an University, Yan'an, China
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Padilla-Roji I, Ruiz-Jiménez L, Bakhat N, Vielba-Fernández A, Pérez-García A, Fernández-Ortuño D. RNAi Technology: A New Path for the Research and Management of Obligate Biotrophic Phytopathogenic Fungi. Int J Mol Sci 2023; 24:ijms24109082. [PMID: 37240427 DOI: 10.3390/ijms24109082] [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: 04/05/2023] [Revised: 05/05/2023] [Accepted: 05/10/2023] [Indexed: 05/28/2023] Open
Abstract
Powdery mildew and rust fungi are major agricultural problems affecting many economically important crops and causing significant yield losses. These fungi are obligate biotrophic parasites that are completely dependent on their hosts for growth and reproduction. Biotrophy in these fungi is determined by the presence of haustoria, specialized fungal cells that are responsible for nutrient uptake and molecular dialogue with the host, a fact that undoubtedly complicates their study under laboratory conditions, especially in terms of genetic manipulation. RNA interference (RNAi) is the biological process of suppressing the expression of a target gene through double-stranded RNA that induces mRNA degradation. RNAi technology has revolutionized the study of these obligate biotrophic fungi by enabling the analysis of gene function in these fungal. More importantly, RNAi technology has opened new perspectives for the management of powdery mildew and rust diseases, first through the stable expression of RNAi constructs in transgenic plants and, more recently, through the non-transgenic approach called spray-induced gene silencing (SIGS). In this review, the impact of RNAi technology on the research and management of powdery mildew and rust fungi will be addressed.
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Affiliation(s)
- Isabel Padilla-Roji
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29071 Málaga, Spain
| | - Laura Ruiz-Jiménez
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29071 Málaga, Spain
| | - Nisrine Bakhat
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29071 Málaga, Spain
| | - Alejandra Vielba-Fernández
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29071 Málaga, Spain
| | - Alejandro Pérez-García
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29071 Málaga, Spain
| | - Dolores Fernández-Ortuño
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29071 Málaga, Spain
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3
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Liu Y, Shen S, Hao Z, Wang Q, Zhang Y, Zhao Y, Tong Y, Zeng F, Dong J. Protein kinase A participates in hyphal and appressorial development by targeting Efg1-mediated transcription of a Rab GTPase in Setosphaeria turcica. MOLECULAR PLANT PATHOLOGY 2022; 23:1608-1619. [PMID: 35929228 PMCID: PMC9562828 DOI: 10.1111/mpp.13253] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 07/12/2022] [Accepted: 07/12/2022] [Indexed: 06/15/2023]
Abstract
The cyclic adenosine monophosphate (cAMP) signalling pathway plays an important role in the regulation of the development and pathogenicity of filamentous fungi. cAMP-dependent protein kinase A (PKA) is the conserved element downstream of cAMP, and its diverse mechanisms in multiple filamentous fungi are not well known yet. In the present study, gene knockout mutants of two catalytic subunits of PKA (PKA-C) in Setosphaeria turcica were created to illustrate the regulatory mechanisms of PKA-Cs on the development and pathogenicity of S. turcica. As a result, StPkaC2 was proved to be the main contributor of PKA activity in S. turcica. In addition, it was found that both StPkaC1 and StPkaC2 were necessary for conidiation and invasive growth, while only StPkaC2 played a negative role in the regulation of filamentous growth. We reveal that only StPkaC2 could interact with the transcription factor StEfg1, and it inhibited the transcription of StRAB1, a Rab GTPase homologue coding gene in S. turcica, whereas StPkaC1 could specifically interact with a transcriptional regulator StFlo8, which could rescue the transcriptional inhibition of StEfg1 on StRAB1. We also demonstrated that StRAB1 could positively influence the biosynthesis of chitin in hyphae, thus changing the filamentous growth. Our findings clarify that StPkaC2 participates in chitin biosynthesis to modulate mycelium development by targeting the Efg1-mediated transcription of StRAB1, while StFlo8, interacting with StPkaC1, acts as a negative regulator during this process.
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Affiliation(s)
- Yuwei Liu
- State Key Laboratory of North China Crop Improvement and RegulationBaodingChina
- College of Life SciencesHebei Agricultural UniversityBaodingChina
- Key Laboratory of Hebei Province for Plant Physiology and Molecular PathologyBaodingChina
| | - Shen Shen
- State Key Laboratory of North China Crop Improvement and RegulationBaodingChina
- College of Life SciencesHebei Agricultural UniversityBaodingChina
- Key Laboratory of Hebei Province for Plant Physiology and Molecular PathologyBaodingChina
| | - Zhimin Hao
- State Key Laboratory of North China Crop Improvement and RegulationBaodingChina
- College of Life SciencesHebei Agricultural UniversityBaodingChina
- Key Laboratory of Hebei Province for Plant Physiology and Molecular PathologyBaodingChina
| | - Qing Wang
- College of Life SciencesHebei Agricultural UniversityBaodingChina
- Key Laboratory of Hebei Province for Plant Physiology and Molecular PathologyBaodingChina
| | - Yumei Zhang
- College of Life SciencesHebei Agricultural UniversityBaodingChina
- Key Laboratory of Hebei Province for Plant Physiology and Molecular PathologyBaodingChina
| | - Yulan Zhao
- College of Life SciencesHebei Agricultural UniversityBaodingChina
- Key Laboratory of Hebei Province for Plant Physiology and Molecular PathologyBaodingChina
| | - Yameng Tong
- State Key Laboratory of North China Crop Improvement and RegulationBaodingChina
- College of Life SciencesHebei Agricultural UniversityBaodingChina
- Key Laboratory of Hebei Province for Plant Physiology and Molecular PathologyBaodingChina
| | - Fanli Zeng
- State Key Laboratory of North China Crop Improvement and RegulationBaodingChina
- College of Life SciencesHebei Agricultural UniversityBaodingChina
- Key Laboratory of Hebei Province for Plant Physiology and Molecular PathologyBaodingChina
| | - Jingao Dong
- State Key Laboratory of North China Crop Improvement and RegulationBaodingChina
- Key Laboratory of Hebei Province for Plant Physiology and Molecular PathologyBaodingChina
- College of Plant ProtectionHebei Agricultural UniversityBaodingChina
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Yang Y, Xie B, Jing Z, Lu Y, Ye J, Chen Y, Liu F, Li S, Xie B, Tao Y. Flammulina filiformis Pkac Gene Complementing in Neurospora crassa Mutant Reveals Its Function in Mycelial Growth and Abiotic Stress Response. Life (Basel) 2022; 12:life12091336. [PMID: 36143373 PMCID: PMC9502917 DOI: 10.3390/life12091336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 08/22/2022] [Accepted: 08/23/2022] [Indexed: 12/01/2022] Open
Abstract
Flammulina filiformis is a popular edible mushroom that easily suffers from heat and oxidative stresses. The cyclic adenylate-dependent protein kinase A (cAMP/PKA) pathway is the main signaling pathway in response to environmental stress, and the PKAC is the terminal catalytic subunit of this pathway. In this study, the Pkac gene was identified in F. filiformis, which was highly conserved in basidiomycetes and ascomycetes. The transcription analysis showed that the Pkac gene was involved in the mycelial growth and the fruiting body development of fungi. In Neurospora crassa, the Pkac gene deletion (ΔPkac) resulted in the slower growth of the mycelia. We complemented the F. filiformis FfPkac to N. crassa ΔPkac mutant to obtain the CPkac strain. The mycelial growth in the CPkac strain was restored to the same level as the WT strain. In addition, the FfPkac gene showed significantly up-regulated expression under heat and oxidative stresses. By analyzing the differentially expressed genes of ΔPkac and Cpkac with WT, respectively, seven downstream genes regulated by Pkac were identified and may be related to mycelial growth. They were mainly focused on microbial metabolism in diverse environments, mitochondrial biogenesis, protein translation and nucleocytoplasmic transport. RT-qPCR results confirmed that the expression patterns of these seven genes were consistent with FfPkac under heat and oxidative stresses. The results revealed the conserved functions of PKAC in filamentous fungi and its regulatory mechanism in response to heat and oxidative stresses.
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Affiliation(s)
- Yayong Yang
- College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Mycological Research Center, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Bin Xie
- Mycological Research Center, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Zhuohan Jing
- College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Mycological Research Center, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Yuanping Lu
- Mycological Research Center, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Jun Ye
- College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Mycological Research Center, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Yizhao Chen
- College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Mycological Research Center, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Fang Liu
- Mycological Research Center, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Shaojie Li
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Baogui Xie
- Mycological Research Center, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Correspondence: (B.X.); (Y.T.); Tel.: +86-0591-83789281 (Y.T.)
| | - Yongxin Tao
- College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Mycological Research Center, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Correspondence: (B.X.); (Y.T.); Tel.: +86-0591-83789281 (Y.T.)
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Secretion of the siderophore rhizoferrin is regulated by the cAMP-PKA pathway and is involved in the virulence of Mucor lusitanicus. Sci Rep 2022; 12:10649. [PMID: 35739200 PMCID: PMC9226013 DOI: 10.1038/s41598-022-14515-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 06/08/2022] [Indexed: 11/08/2022] Open
Abstract
Mucormycosis is a fungal infection caused by Mucorales, with a high mortality rate. However, only a few virulence factors have been described in these organisms. This study showed that deletion of rfs, which encodes the enzyme for the biosynthesis of rhizoferrin, a siderophore, in Mucor lusitanicus, led to a lower virulence in diabetic mice and nematodes. Upregulation of rfs correlated with the increased toxicity of the cell-free supernatants of the culture broth (SS) obtained under growing conditions that favor oxidative metabolism, such as low glucose levels or the presence of H2O2 in the culture, suggesting that oxidative metabolism enhances virulence through rhizoferrin production. Meanwhile, growing M. lusitanicus in the presence of potassium cyanide, N-acetylcysteine, a higher concentration of glucose, or exogenous cAMP, or the deletion of the gene encoding the regulatory subunit of PKA (pkaR1), correlated with a decrease in the toxicity of SS, downregulation of rfs, and reduction in rhizoferrin production. These observations indicate the involvement of the cAMP-PKA pathway in the regulation of rhizoferrin production and virulence in M. lusitanicus. Moreover, rfs upregulation was observed upon macrophage interaction or during infection with spores in mice, suggesting a pivotal role of rfs in M. lusitanicus infection.
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Wang F, Liu K, Wang J, Sun Y, Xiao S, Xue C. ClNOX1/ClNOXR-mediated MAPK and cAMP-PKA signalling pathways and ROS metabolism are involved in Curvularia lunata sexual reproduction and host infection. Environ Microbiol 2022; 24:4340-4355. [PMID: 35676222 DOI: 10.1111/1462-2920.16089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Revised: 05/28/2022] [Accepted: 05/30/2022] [Indexed: 11/29/2022]
Abstract
NADPH oxidases (NOXs) and hydrogen peroxide (H2 O2 ) are involved in physiological and pathological processes, and cell fate decisions in organisms. However, regulatory mechanism of NOXs and the role of H2 O2 on fungal sexual reproduction and host infection remain largely unexplored. Here, we identified ROS metabolic genes and key signalling genes of MAPK and cAMP-PKA pathways in Curvularia lunata, which were NOX ClNOX1 and ClNOXR, superoxide dismutase ClSOD1 and catalase ClCAT4, redox-regulated transcription factor ClAP1, Ras small GTPases Clg2P, pheromone-response MAPK ClK1 and cAMP-PKA ClSCHA, and characterized the functions of these genes. The results showed that ClNOX1 localized to the plasma membrane. ClNOX1 and ClNOXR were involved in sexual reproduction and host infection via ClNOX1/ClNOXR-derived H2 O2 as well as MAPK and cAMP-PKA signalling pathways. H2 O2 acted as a signalling molecule to regulate sexual reproduction and host infection in C. lunata.
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Affiliation(s)
- Fen Wang
- College of Plant Protection, Shenyang Agriculture University, Shenyang, 110161, China
| | - Kexin Liu
- College of Plant Protection, Shenyang Agriculture University, Shenyang, 110161, China
| | - Jiahui Wang
- College of Plant Protection, Shenyang Agriculture University, Shenyang, 110161, China
| | - Yuxin Sun
- College of Plant Protection, Shenyang Agriculture University, Shenyang, 110161, China
| | - Shuqin Xiao
- College of Plant Protection, Shenyang Agriculture University, Shenyang, 110161, China
| | - Chunsheng Xue
- College of Plant Protection, Shenyang Agriculture University, Shenyang, 110161, China
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Meteyer CU, Dutheil JY, Keel MK, Boyles JG, Stukenbrock EH. Plant pathogens provide clues to the potential origin of bat white-nose syndrome Pseudogymnoascus destructans. Virulence 2022; 13:1020-1031. [PMID: 35635339 PMCID: PMC9176227 DOI: 10.1080/21505594.2022.2082139] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
White-nose syndrome has killed millions of bats, yet both the origins and infection strategy of the causative fungus, Pseudogymnoascus destructans, remain elusive. We provide evidence for a novel hypothesis that P. destructans emerged from plant-associated fungi and retained invasion strategies affiliated with fungal pathogens of plants. We demonstrate that P. destructans invades bat skin in successive biotrophic and necrotrophic stages (hemibiotrophic infection), a mechanism previously only described in plant fungal pathogens. Further, the convergence of hyphae at hair follicles suggests nutrient tropism. Tropism, biotrophy, and necrotrophy are often associated with structures termed appressoria in plant fungal pathogens; the penetrating hyphae produced by P. destructans resemble appressoria. Finally, we conducted a phylogenomic analysis of a taxonomically diverse collection of fungi. Despite gaps in genetic sampling of prehistoric and contemporary fungal species, we estimate an 88% probability the ancestral state of the clade containing P. destructans was a plant-associated fungus.
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Affiliation(s)
- Carol Uphoff Meteyer
- U.S. Geological Survey, National Wildlife Health Center, Madison, Wisconsin 53711
| | - Julien Y. Dutheil
- Molecular Systems Evolution, Max Planck Institute for Evolutionary Biology, 24306 Plön, Germany
| | - M. Kevin Keel
- School of Veterinary Medicine, Dept of Pathology, Microbiology & Immunology, University of California, Davis, California 95616
| | - Justin G. Boyles
- Cooperative Wildlife Research Laboratory and School of Biological Sciences, Southern Illinois University, Carbondale, Illinois 62901
| | - Eva H. Stukenbrock
- Environmental Genomics Group, Botanical Institute, Christian-Albrechts University of Kiel, Kiel, Germany and Max Planck Institute for Evolutionary Biology, 24306 Plön, Germany
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8
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Adenylyl Cyclase and Protein Kinase A Play Redundant and Distinct Roles in Growth, Differentiation, Antifungal Drug Resistance, and Pathogenicity of Candida auris. mBio 2021; 12:e0272921. [PMID: 34663094 PMCID: PMC8524339 DOI: 10.1128/mbio.02729-21] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Candida auris is a globally emerging multidrug-resistant fungal pathogen. Its pathogenicity-related signaling networks are largely unknown. Here, we characterized the pathobiological functions of the cyclic AMP (cAMP)/protein kinase A (PKA) signaling pathway in C. auris. We focused on adenylyl cyclase (CYR1), the PKA regulatory subunit (BCY1), and the PKA catalytic subunits (TPK1 and TPK2). We concluded that PKA acts both dependently and independently of Cyr1 in C. auris. Tpk1 and Tpk2 have major and minor roles, respectively, in PKA activity and functions. Both Cyr1 and PKA promote growth, thermotolerance, filamentous growth, and resistance to stress and antifungal drugs by regulating expression of multiple effector genes. In addition, Cyr1 and PKA subunits were involved in disinfectant resistance of C. auris. However, deletion of both TPK1 and TPK2 generally resulted in more severe defects than CYR1 deletion, indicating that Cyr1 and PKA play redundant and distinct roles. Notably, Tpk1 and Tpk2 have redundant but Cyr1-independent roles in haploid-to-diploid cell transition, which increases virulence of C. auris. However, Tpk1 and Tpk2 often play opposing roles in formation of biofilms and the cell wall components chitin and chitosan. Surprisingly, deletion of CYR1 or TPK1/TPK2, which resulted in severe in vitro growth defects at 37°C, did not attenuate virulence, and BCY1 deletion reduced virulence of C. auris in a systemic murine infection model. In conclusion, this study provides comprehensive insights into the role of the cAMP/PKA pathway in drug resistance and pathogenicity of C. auris and suggests a potential therapeutic option for treatment of C. auris-mediated candidemia.
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Padder SA, Ramzan A, Tahir I, Rehman RU, Shah AH. Metabolic flexibility and extensive adaptability governing multiple drug resistance and enhanced virulence in Candida albicans. Crit Rev Microbiol 2021; 48:1-20. [PMID: 34213983 DOI: 10.1080/1040841x.2021.1935447] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Commensal fungus-Candida albicans turn pathogenic during the compromised immunity of the host, causing infections ranging from superficial mucosal to dreadful systemic ones. C. albicans has evolved various adaptive measures which collectively contribute towards its enhanced virulence. Among fitness attributes, metabolic flexibility and vigorous stress response are essential for its pathogenicity and virulence. Metabolic flexibility provides a means for nutrient assimilation and growth in diverse host microenvironments and reduces the vulnerability of the pathogen to various antifungals besides evading host immune response(s). Inside the host micro-environments, C. albicans efficiently utilizes the multiple fermentable and non-fermentable carbon sources to sustain and proliferate in glucose deficit conditions. The utilization of alternative carbon sources further highlights the importance of understanding these pathways as the attractive and potential therapeutic target. A thorough understanding of metabolic flexibility and adaptation to environmental stresses is warranted to decipher in-depth insights into virulence and molecular mechanisms of fungal pathogenicity. In this review, we have attempted to provide a detailed and recent understanding of some key aspects of fungal biology. Particular focus will be placed on processes like nutrient assimilation and utilization, metabolic adaptability, virulence factors, and host immune response in C. albicans leading to its enhanced pathogenicity.
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Affiliation(s)
- Sajad Ahmad Padder
- Department of Bioresources, School of Biological Sciences, University of Kashmir, Srinagar, India
| | - Asiya Ramzan
- Department of Bioresources, School of Biological Sciences, University of Kashmir, Srinagar, India
| | - Inayatullah Tahir
- Departments of Botany, School of Biological Sciences, University of Kashmir, Srinagar, India
| | - Reiaz Ul Rehman
- Department of Bioresources, School of Biological Sciences, University of Kashmir, Srinagar, India
| | - Abdul Haseeb Shah
- Department of Bioresources, School of Biological Sciences, University of Kashmir, Srinagar, India
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Zou L, Mei Z, Guan T, Zhang B, Deng Q. Underlying mechanisms of the effect of minocycline against Candida albicans biofilms. Exp Ther Med 2021; 21:413. [PMID: 33747154 PMCID: PMC7967842 DOI: 10.3892/etm.2021.9857] [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: 04/20/2020] [Accepted: 10/26/2020] [Indexed: 12/14/2022] Open
Abstract
Minocycline (MH) is a broad-spectrum antimicrobial agent and semisynthetic tetracycline derivative, which has been widely used in the clinic due to its efficacy. Having the strongest anti-microbial effect, MH exceeded the traditional scope of antibiotics and its previously unknown antifungal activity is also gradually being discovered. To preliminarily investigate the inhibitory effect of MH on Candida albicans (C. albicans), changes of cell growth, hyphal formation and transition, biofilm production and signaling pathway gene expression of C. albicans in the presence of MH were assessed in the present study. An XTT reduction assay was performed to quantitatively detect the metabolic activity of biofilms and evaluate the inhibition of MH on this. The results suggested that biofilm formation was clearly inhibited by 67% (P<0.0001) in the presence of 250 µg/ml MH, while mature biofilms were not significantly affected. In addition, MH inhibited the transition from yeast to hypha in a dose-dependent manner. Furthermore, reverse transcription-quantitative PCR revealed that several hyphae- and adhesion-specific genes associated with the Ras/cyclic (c)AMP/protein kinase A (PKA) pathway were differentially expressed following MH treatment, including downregulation of ras family GTPase (RAS1), adenylyl cyclase-associated protein 1 (CAP1), thiamin pyrophosphokinase 1 (TPK1), adenylate cyclase (CDC35), transcription factor (TEC1), agglutinin-like protein 3 (ALS3) and hyphal wall protein 1 (HWP1) and upregulation of EFG1 (enhanced filamentous growth protein 1 gene) and PDE2 (high-affinity phosphodiesterase gene). The most obviously changed genes were TPK1, HWP1 and RAS1, downregulated by 0.33-, 0.48- and 0.55-fold, respectively. It was suggested that MH is associated with alterations in the morphology of C. albicans, such as the repression of hypha and biofilm formation of cells, and MH affected the Ras/cAMP pathway to regulate the expression of cAMP-associated genes.
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Affiliation(s)
- Li Zou
- Department of Clinical Laboratory, The People's Hospital of China Three Gorges University, Yichang, Hubei 443000, P.R. China
| | - Zhao Mei
- Department of Pharmacy, The People's Hospital of China Three Gorges University, Yichang, Hubei 443000, P.R. China.,Medical College of China Three Gorges University, Yichang, Hubei 443000, P.R. China
| | - Tao Guan
- Department of Clinical Laboratory, The People's Hospital of China Three Gorges University, Yichang, Hubei 443000, P.R. China
| | - Bo Zhang
- Department of Clinical Laboratory, The People's Hospital of China Three Gorges University, Yichang, Hubei 443000, P.R. China
| | - Qun Deng
- Department of Clinical Laboratory, The People's Hospital of China Three Gorges University, Yichang, Hubei 443000, P.R. China
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Zhang M, Li Y, Wang T, Bi Y, Li R, Huang Y, Mao R, Jiang Q, Liu Y, Prusky DB. AaPKAc Regulates Differentiation of Infection Structures Induced by Physicochemical Signals From Pear Fruit Cuticular Wax, Secondary Metabolism, and Pathogenicity of Alternaria alternata. FRONTIERS IN PLANT SCIENCE 2021; 12:642601. [PMID: 33968101 PMCID: PMC8096925 DOI: 10.3389/fpls.2021.642601] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 03/16/2021] [Indexed: 05/03/2023]
Abstract
Alternaria alternata, the casual agent of black rot of pear fruit, can sense and respond to the physicochemical cues from the host surface and form infection structures during infection. To evaluate the role of cyclic AMP-dependent protein kinase (cAMP-PKA) signaling in surface sensing of A. alternata, we isolated and functionally characterized the cyclic adenosine monophosphate-dependent protein kinase A catalytic subunit gene (AaPKAc). Gene expression results showed that AaPKAc was strongly expressed during the early stages of appressorium formation on hydrophobic surfaces. Knockout mutants ΔAaPKAc were generated by replacing the target genes via homologous recombination events. We found that intracellular cAMP content increased but PKA content decreased in ΔAaPKAc mutant strain. Appressorium formation and infection hyphae were reduced in the ΔAaPKAc mutant strain, and the ability of the ΔAaPKAc mutant strain to recognize and respond to high hydrophobicity surfaces and different surface waxes was lower than in the wild type (WT) strain. In comparison with the WT strain, the appressorium formation rate of the ΔAaPKAc mutant strain on high hydrophobicity and fruit wax extract surface was reduced by 31.6 and 49.3% 4 h after incubation, respectively. In addition, AaPKAc is required for the hypha growth, biomass, pathogenicity, and toxin production of A. alternata. However, AaPKAc negatively regulated conidia formation, melanin production, and osmotic stress resistance. Collectively, AaPKAc is required for pre-penetration, developmental, physiological, and pathological processes in A. alternata.
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Affiliation(s)
- Miao Zhang
- College of Food Science and Engineering, Gansu Agricultural University, Lanzhou, China
| | - Yongcai Li
- College of Food Science and Engineering, Gansu Agricultural University, Lanzhou, China
- *Correspondence: Yongcai Li,
| | - Tiaolan Wang
- College of Food Science and Engineering, Gansu Agricultural University, Lanzhou, China
| | - Yang Bi
- College of Food Science and Engineering, Gansu Agricultural University, Lanzhou, China
| | - Rong Li
- College of Food Science and Engineering, Gansu Agricultural University, Lanzhou, China
| | - Yi Huang
- College of Food Science and Engineering, Gansu Agricultural University, Lanzhou, China
| | - Renyan Mao
- College of Food Science and Engineering, Gansu Agricultural University, Lanzhou, China
| | - Qianqian Jiang
- College of Food Science and Engineering, Gansu Agricultural University, Lanzhou, China
| | - Yongxiang Liu
- College of Food Science and Engineering, Gansu Agricultural University, Lanzhou, China
| | - Dov B. Prusky
- College of Food Science and Engineering, Gansu Agricultural University, Lanzhou, China
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel
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Kijpornyongpan T, Aime MC. Investigating the Smuts: Common Cues, Signaling Pathways, and the Role of MAT in Dimorphic Switching and Pathogenesis. J Fungi (Basel) 2020; 6:jof6040368. [PMID: 33339287 PMCID: PMC7766764 DOI: 10.3390/jof6040368] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 12/10/2020] [Accepted: 12/14/2020] [Indexed: 12/11/2022] Open
Abstract
The corn smut fungus Ustilago maydis serves as a model species for studying fungal dimorphism and its role in phytopathogenic development. The pathogen has two growth phases: a saprobic yeast phase and a pathogenic filamentous phase. Dimorphic transition of U. maydis involves complex processes of signal perception, mating, and cellular reprogramming. Recent advances in improvement of reference genomes, high-throughput sequencing and molecular genetics studies have been expanding research in this field. However, the biology of other non-model species is frequently overlooked. This leads to uncertainty regarding how much of what is known in U. maydis is applicable to other dimorphic fungi. In this review, we will discuss dimorphic fungi in the aspects of physiology, reproductive biology, genomics, and molecular genetics. We also perform comparative analyses between U. maydis and other fungi in Ustilaginomycotina, the subphylum to which U. maydis belongs. We find that lipid/hydrophobicity is a potential common cue for dimorphic transition in plant-associated dimorphic fungi. However, genomic profiles alone are not adequate to explain dimorphism across different fungi.
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Valle-Maldonado MI, Patiño-Medina JA, Pérez-Arques C, Reyes-Mares NY, Jácome-Galarza IE, Ortíz-Alvarado R, Vellanki S, Ramírez-Díaz MI, Lee SC, Garre V, Meza-Carmen V. The heterotrimeric G-protein beta subunit Gpb1 controls hyphal growth under low oxygen conditions through the protein kinase A pathway and is essential for virulence in the fungus Mucor circinelloides. Cell Microbiol 2020; 22:e13236. [PMID: 32562333 DOI: 10.1111/cmi.13236] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 05/24/2020] [Accepted: 06/09/2020] [Indexed: 12/13/2022]
Abstract
Mucor circinelloides, a dimorphic opportunistic pathogen, expresses three heterotrimeric G-protein beta subunits (Gpb1, Gpb2 and Gpb3). The Gpb1-encoding gene is up-regulated during mycelial growth compared with that in the spore or yeast stage. gpb1 deletion mutation analysis revealed its relevance for an adequate development during the dimorphic transition and for hyphal growth under low oxygen concentrations. Infection assays in mice indicated a phenotype with considerably reduced virulence and tissue invasiveness in the deletion mutants (Δgpb1) and decreased host inflammatory response. This finding could be attributed to the reduced filamentous growth in animal tissues compared with that of the wild-type strain. Mutation in a regulatory subunit of cAMP-dependent protein kinase A (PKA) subunit (PkaR1) resulted in similar phenotypes to Δgpb1. The defects exhibited by the Δgpb1 strain were genetically suppressed by pkaR1 overexpression, indicating that the PKA pathway is controlled by Gpb1 in M. circinelloides. Moreover, during growth under low oxygen levels, cAMP levels were much higher in the Δgpb1 than in the wild-type strain, but similar to those in the ΔpkaR1 strain. These findings reveal that M. circinelloides possesses a signal transduction pathway through which the Gpb1 heterotrimeric G subunit and PkaR1 control mycelial growth in response to low oxygen levels.
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Affiliation(s)
- Marco Iván Valle-Maldonado
- Instituto de Investigaciones Químico Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Ciudad Universitaria, Morelia, Mexico
| | - José Alberto Patiño-Medina
- Instituto de Investigaciones Químico Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Ciudad Universitaria, Morelia, Mexico
| | - Carlos Pérez-Arques
- Departamento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, Murcia, Spain
| | - Nancy Yadira Reyes-Mares
- Instituto de Investigaciones Químico Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Ciudad Universitaria, Morelia, Mexico
| | | | - Rafael Ortíz-Alvarado
- Facultad de Quimico Farmacobiología, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Mexico
| | - Sandeep Vellanki
- South Texas Center for Emerging Infectious Diseases (STCEID), Department of Biology, The University of Texas at San Antonio, San Antonio, Texas, USA
| | - Martha Isela Ramírez-Díaz
- Instituto de Investigaciones Químico Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Ciudad Universitaria, Morelia, Mexico
| | - Soo Chan Lee
- South Texas Center for Emerging Infectious Diseases (STCEID), Department of Biology, The University of Texas at San Antonio, San Antonio, Texas, USA
| | - Victoriano Garre
- Departamento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, Murcia, Spain
| | - Víctor Meza-Carmen
- Instituto de Investigaciones Químico Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Ciudad Universitaria, Morelia, Mexico
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Liu H, Chen J, Xia Z, An M, Wu Y. Effects of ε-poly-l-lysine on vegetative growth, pathogenicity and gene expression of Alternaria alternata infecting Nicotiana tabacum. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2020; 163:147-153. [PMID: 31973852 DOI: 10.1016/j.pestbp.2019.11.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2019] [Revised: 11/04/2019] [Accepted: 11/06/2019] [Indexed: 06/10/2023]
Abstract
Microbial secondary metabolites produced by Streptomyces are applied to control plant diseases. ε-poly-l-lysine (ε-PL) is a non-toxic food preservative, but the potential application of ε-PL as a microbial fungicide in agriculture has rarely been reported. In this study, Alternaria alternata (A. alternata) was used to reveal the effect and mode of action for ε-PL on the plant pathogenic fungi. The results showed that ε-PL effectively inhibited necrotic-lesion development caused by A. alternata on tobacco. Mycelial growth was also significantly inhibited in vitro by 100 μg/ml ε-PL using in vitro analysis. Moreover, 25 μg/ml ε-PL inhibited spore germination and induced abnormal morphological development of A. alternata hyphae. To clarify the molecular-genetic antifungal mechanisms, we selected several crucial genes involved in the development and pathogenesis of A. alternata and studied their expression regulated by ε-PL. Results of real-time quantitative PCR showed that a mycelium morphology and pathogenic process related cyclic adenosine monophosphate protein (cAMP) dependent protein kinase A (PKA), Alternaria alternata cAMP-dependent protein kinase catalytic subunit (AAPK1) and the early infection-related glyceraldehyde-3-phosphate dehydrogenase (GAPDH) were down-regulated after ε-PL treatment. The results provide novel insights for the application of ε-PL in the control of plant diseases caused by A. alternata.
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Affiliation(s)
- He Liu
- College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, Liaoning, China
| | - Jianguang Chen
- College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, Liaoning, China
| | - Zihao Xia
- College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, Liaoning, China
| | - Mengnan An
- College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, Liaoning, China.
| | - Yuanhua Wu
- College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, Liaoning, China.
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Patiño-Medina JA, Reyes-Mares NY, Valle-Maldonado MI, Jácome-Galarza IE, Pérez-Arques C, Nuñez-Anita RE, Campos-García J, Anaya-Martínez V, Ortiz-Alvarado R, Ramírez-Díaz MI, Chan Lee S, Garre V, Meza-Carmen V. Heterotrimeric G-alpha subunits Gpa11 and Gpa12 define a transduction pathway that control spore size and virulence in Mucor circinelloides. PLoS One 2019; 14:e0226682. [PMID: 31887194 PMCID: PMC6936849 DOI: 10.1371/journal.pone.0226682] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 12/03/2019] [Indexed: 02/07/2023] Open
Abstract
Mucor circinelloides is one of the causal agents of mucormycosis, an emerging and high mortality rate fungal infection produced by asexual spores (sporangiospores) of fungi that belong to the order Mucorales. M. circinelloides has served as a model genetic system to understand the virulence mechanism of this infection. Although the G-protein signaling cascade plays crucial roles in virulence in many pathogenic fungi, its roles in Mucorales are yet to be elucidated. Previous study found that sporangiospore size and calcineurin are related to the virulence in Mucor, in which larger spores are more virulent in an animal mucormycosis model and loss of a calcineurin A catalytic subunit CnaA results in larger spore production and virulent phenotype. The M. circinelloides genome is known to harbor twelve gpa (gpa1 to gpa12) encoding G-protein alpha subunits and the transcripts of the gpa11 and gpa12 comprise nearly 72% of all twelve gpa genes transcript in spores. In this study we demonstrated that loss of function of Gpa11 and Gpa12 led to larger spore size associated with reduced activation of the calcineurin pathway. Interestingly, we found lower levels of the cnaA mRNAs in sporangiospores from the Δgpa12 and double Δgpa11/Δgpa12 mutant strains compared to wild-type and the ΔcnaA mutant had significantly lower gpa11 and gpa12 mRNA levels compared to wild-type. However, in contrast to the high virulence showed by the large spores of ΔcnaA, the spores from Δgpa11/Δgpa12 were avirulent and produced lower tissue invasion and cellular damage, suggesting that the gpa11 and gpa12 define a signal pathway with two branches. One of the branches controls spore size through regulation of calcineurin pathway, whereas virulences is controlled by an independent pathway. This virulence-related regulatory pathway could control the expression of genes involved in cellular responses important for virulence, since sporangiospores of Δgpa11/Δgpa12 were less resistant to oxidative stress and phagocytosis by macrophages than the ΔcnaA and wild-type strains. The characterization of this pathway could contribute to decipher the signals and mechanism used by Mucorales to produce mucormycosis.
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Affiliation(s)
- J. Alberto Patiño-Medina
- Instituto de Investigaciones Químico Biológicas, Universidad Michoacana de San Nicolás de Hidalgo (UMSNH), Morelia, Michoacán, México
| | - Nancy Y. Reyes-Mares
- Instituto de Investigaciones Químico Biológicas, Universidad Michoacana de San Nicolás de Hidalgo (UMSNH), Morelia, Michoacán, México
| | - Marco I. Valle-Maldonado
- Instituto de Investigaciones Químico Biológicas, Universidad Michoacana de San Nicolás de Hidalgo (UMSNH), Morelia, Michoacán, México
| | - Irvin E. Jácome-Galarza
- Departamento de Biología Molecular, Laboratorio Estatal de Salud Pública del Estado de Michoacán, Morelia, Michoacán, México
| | - Carlos Pérez-Arques
- Departamento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, Murcia, España
| | - Rosa E. Nuñez-Anita
- Facultad de Medicina Veterinaria y Zootecnia, Universidad Michoacana de San Nicolás Hidalgo, Morelia, Michoacán, Mexico
| | - Jesús Campos-García
- Instituto de Investigaciones Químico Biológicas, Universidad Michoacana de San Nicolás de Hidalgo (UMSNH), Morelia, Michoacán, México
| | - Verónica Anaya-Martínez
- Facultad de Ciencias de la Salud, Universidad Anáhuac, Naucalpan de Juarez, Estado de México, México
| | - Rafael Ortiz-Alvarado
- Facultad de Químico Farmacobiología, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacan, México
| | - Martha I. Ramírez-Díaz
- Instituto de Investigaciones Químico Biológicas, Universidad Michoacana de San Nicolás de Hidalgo (UMSNH), Morelia, Michoacán, México
| | - Soo Chan Lee
- Department of Biology, South Texas Center of Emerging Infectious Diseases (STCEID), University of Texas at San Antonio, San Antonio, Texas, United States of America
| | - Victoriano Garre
- Departamento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, Murcia, España
| | - Víctor Meza-Carmen
- Instituto de Investigaciones Químico Biológicas, Universidad Michoacana de San Nicolás de Hidalgo (UMSNH), Morelia, Michoacán, México
- * E-mail:
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16
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Li S, Giardina DM, Siegal ML. Control of nongenetic heterogeneity in growth rate and stress tolerance of Saccharomyces cerevisiae by cyclic AMP-regulated transcription factors. PLoS Genet 2018; 14:e1007744. [PMID: 30388117 PMCID: PMC6241136 DOI: 10.1371/journal.pgen.1007744] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 11/14/2018] [Accepted: 10/05/2018] [Indexed: 01/01/2023] Open
Abstract
Genetically identical cells exhibit extensive phenotypic variation even under constant and benign conditions. This so-called nongenetic heterogeneity has important clinical implications: within tumors and microbial infections, cells show nongenetic heterogeneity in growth rate and in susceptibility to drugs or stress. The budding yeast, Saccharomyces cerevisiae, shows a similar form of nongenetic heterogeneity in which growth rate correlates positively with susceptibility to acute heat stress at the single-cell level. Using genetic and chemical perturbations, combined with high-throughput single-cell assays of yeast growth and gene expression, we show here that heterogeneity in intracellular cyclic AMP (cAMP) levels acting through the conserved Ras/cAMP/protein kinase A (PKA) pathway and its target transcription factors, Msn2 and Msn4, underlies this nongenetic heterogeneity. Lower levels of cAMP correspond to slower growth, as shown by direct comparison of cAMP concentration in subpopulations enriched for slower vs. faster growing cells. Concordantly, an endogenous reporter of this pathway’s activity correlates with growth in individual cells. The paralogs Msn2 and Msn4 differ in their roles in nongenetic heterogeneity in a way that demonstrates slow growth and stress tolerance are not inevitably linked. Heterogeneity in growth rate requires each, whereas only Msn2 is required for heterogeneity in expression of Tsl1, a subunit of trehalose synthase that contributes to acute-stress tolerance. Perturbing nongenetic heterogeneity by mutating genes in this pathway, or by culturing wild-type cells with the cell-permeable cAMP analog 8-bromo-cAMP or the PKA inhibitor H89, significantly impacts survival of acute heat stress. Perturbations that increase intracellular cAMP levels reduce the slower-growing subpopulation and increase susceptibility to acute heat stress, whereas PKA inhibition slows growth and decreases susceptibility to acute heat stress. Loss of Msn2 reduces, but does not completely eliminate, the correlation in individual cells between growth rate and acute-stress survival, suggesting a major role for the Msn2 pathway in nongenetic heterogeneity but also a residual benefit of slow growth. Our results shed light on the genetic control of nongenetic heterogeneity and suggest a possible means of defeating bet-hedging pathogens or tumor cells by making them more uniformly susceptible to treatment. Nongenetic heterogeneity exists when a trait differs among individuals that have identical genotypes and environments. A clonal population can maximize its long-term success in an uncertain environment by diversifying its phenotypes via nongenetic heterogeneity: the currently unfavored ones may become the favored ones when conditions change. Nongenetic heterogeneity has clinical relevance. For example, populations of tumor cells or infectious microbes show cell-to-cell differences in growth and in drug or stress tolerance. This heterogeneity hampers efficient treatment and can potentiate harmful evolution of a tumor or pathogen. We show that in budding yeast, heterogeneity in intracellular cyclic AMP levels acting through the conserved Ras/cAMP/protein kinase A (PKA) pathway and its target transcription factors, Msn2 and Msn4, underlies the nongenetic heterogeneity of both single-cell growth rate and acute heat-stress tolerance. Perturbations of this pathway significantly affect population survival upon acute heat stress. These results illuminate a mechanism of nongenetic heterogeneity and suggest the potential value of antitumor or antifungal treatment strategies that target nongenetic heterogeneity to render the tumor or pathogen population more uniformly susceptible to a second drug that aims to kill.
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Affiliation(s)
- Shuang Li
- Center for Genomics and Systems Biology, Department of Biology, New York University, New York, New York, United States of America
| | - Daniella M. Giardina
- Center for Genomics and Systems Biology, Department of Biology, New York University, New York, New York, United States of America
| | - Mark L. Siegal
- Center for Genomics and Systems Biology, Department of Biology, New York University, New York, New York, United States of America
- * E-mail:
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Abstract
Candida tropicalis is one of the most important human fungal pathogens causing superficial infections in locations such as the oral mucosa and genital tract, as well as systemic infections with high mortality. In its sister species Candida albicans, the cyclic AMP/protein kinase A (cAMP/PKA) pathway regulates fungal adhesion and dimorphism, both of which correlate closely with virulence. CaTpk1 and CaTpk2, the catalytic subunits of PKA, not only share redundant functions in hyphal growth, adhesion, and biofilm formation, but also have distinct roles in stress responses and pathogenesis, respectively. However, studies on PKA in the emerging fungal pathogen C. tropicalis are limited. Our results suggest that Tpk1 is involved in cell wall integrity and drug tolerance. The tpk2/tpk2 mutants, which have no protein kinase A activity, have reduced hyphal growth and adhesion. In addition, the tpk1/tpk1 tpk2/tpk2 double deletion mutant demonstrated delayed growth and impaired hyphal formation. In a murine model of systemic infection, both TPK1 and TPK2 were required for full virulence. We further found that EFG1 and HWP1 expression is regulated by PKA, while BCR1, FLO8, GAL4, and RIM101 are upregulated in the tpk1/tpk1 tpk2/tpk2 mutant. This study demonstrates that Tpk1 is involved in drug tolerance and cell wall integrity, while Tpk2 serves as a key regulator in dimorphism and adhesion. Both Tpk1 and Tpk2 are required for growth and full virulence in C. tropicalis.
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Affiliation(s)
- Chi-Jan Lin
- a Department of Plant Pathology and Microbiology , National Taiwan University , Taipei , Taiwan
| | - Chia-Yen Wu
- a Department of Plant Pathology and Microbiology , National Taiwan University , Taipei , Taiwan
| | - Shang-Jie Yu
- a Department of Plant Pathology and Microbiology , National Taiwan University , Taipei , Taiwan
| | - Ying-Lien Chen
- a Department of Plant Pathology and Microbiology , National Taiwan University , Taipei , Taiwan
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18
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Lin CJ, Chen YL. Conserved and Divergent Functions of the cAMP/PKA Signaling Pathway in Candida albicans and Candida tropicalis. J Fungi (Basel) 2018; 4:E68. [PMID: 29890663 PMCID: PMC6023519 DOI: 10.3390/jof4020068] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 05/28/2018] [Accepted: 06/07/2018] [Indexed: 01/03/2023] Open
Abstract
Fungal species undergo many morphological transitions to adapt to changing environments, an important quality especially in fungal pathogens. For decades, Candida albicans has been one of the most prevalent human fungal pathogens, and recently, the prevalence of Candida tropicalis as a causative agent of candidiasis has increased. In C. albicans, the ability to switch between yeast and hyphal forms is thought to be a key virulence factor and is regulated by multiple signaling cascades—including the cyclic adenosine monophosphate/protein kinase A (cAMP/PKA), calcineurin, high-osmolarity glycerol (HOG), and mitogen-activated protein kinases (MAPK) signaling pathways—upon receiving environmental cues. The cAMP/PKA signaling pathway also triggers white-opaque switching in C. albicans. However, studies on C. tropicalis morphogenesis are limited. In this minireview, we discuss the regulation of the yeast-hypha transition, virulence, and white-opaque switching through the cAMP/PKA pathway in the closely related species C. albicans and C. tropicalis.
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Affiliation(s)
- Chi-Jan Lin
- Department of Plant Pathology and Microbiology, National Taiwan University, 10617 Taipei, Taiwan.
| | - Ying-Lien Chen
- Department of Plant Pathology and Microbiology, National Taiwan University, 10617 Taipei, Taiwan.
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Trevijano-Contador N, de Oliveira HC, García-Rodas R, Rossi SA, Llorente I, Zaballos Á, Janbon G, Ariño J, Zaragoza Ó. Cryptococcus neoformans can form titan-like cells in vitro in response to multiple signals. PLoS Pathog 2018; 14:e1007007. [PMID: 29775477 PMCID: PMC5959073 DOI: 10.1371/journal.ppat.1007007] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 04/03/2018] [Indexed: 02/07/2023] Open
Abstract
Cryptococcus neoformans is an encapsulated pathogenic yeast that can change the size of the cells during infection. In particular, this process can occur by enlarging the size of the capsule without modifying the size of the cell body, or by increasing the diameter of the cell body, which is normally accompanied by an increase of the capsule too. This last process leads to the formation of cells of an abnormal enlarged size denominated titan cells. Previous works characterized titan cell formation during pulmonary infection but research on this topic has been hampered due to the difficulty to obtain them in vitro. In this work, we describe in vitro conditions (low nutrient, serum supplemented medium at neutral pH) that promote the transition from regular to titan-like cells. Moreover, addition of azide and static incubation of the cultures in a CO2 enriched atmosphere favored cellular enlargement. This transition occurred at low cell densities, suggesting that the process was regulated by quorum sensing molecules and it was independent of the cryptococcal serotype/species. Transition to titan-like cell was impaired by pharmacological inhibition of PKC signaling pathway. Analysis of the gene expression profile during the transition to titan-like cells showed overexpression of enzymes involved in carbohydrate metabolism, as well as proteins from the coatomer complex, and related to iron metabolism. Indeed, we observed that iron limitation also induced the formation of titan cells. Our gene expression analysis also revealed other elements involved in titan cell formation, such as calnexin, whose absence resulted in appearance of abnormal large cells even in regular rich media. In summary, our work provides a new alternative method to investigate titan cell formation devoid the bioethical problems that involve animal experimentation. Cryptococcus neoformans is a fungal pathogen that has a significant incidence in HIV+ patients in particular, in Sub-saharan Africa, Asia and South America. This yeast poses an excellent model to investigate fungal virulence because it develops many strategies to adapt to the host and evade the immune response. One of the adaptation mechanisms involves the formation of Titan Cells, which are yeast of an abnormal large size. However, research on these cells has been limited to in vivo studies (mainly in mice) because they were not reproducibly found in vitro. In this work, we describe several conditions that induce the appearance of cells that mimic titan cells, and that we denominated as titan-like cells. The main factor that induced titan-like cells was the addition of serum to nutrient limited media. This has allowed to easily performing new approaches to characterize several signaling pathways involved in their development. We found that the formation of these cells is regulated by quorum sensing molecules, and that pathways such as cAMP and PKC regulate the process of cellular enlargement. We have also performed transcriptomic analysis, which led to the identification of new genes that could be involved in the process. This work will open different research lines that will contribute to the elucidation of the role of these cells during infection and on the development of cryptococcal disease.
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Affiliation(s)
- Nuria Trevijano-Contador
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| | - Haroldo Cesar de Oliveira
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
- Universidade Estadual Paulista (UNESP), Faculdade de Ciências Farmacêuticas, Câmpus Araraquara, Departamento de Análises Clínicas, Laboratório de Micologia Clínica, Araraquara, São Paulo, Brazil
| | - Rocío García-Rodas
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| | - Suélen Andreia Rossi
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| | - Irene Llorente
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| | - Ángel Zaballos
- Genomics Unit, Core Scientific Services, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| | - Guilhem Janbon
- Institut Pasteur, Unité Biologie des ARN des Pathogènes Fongiques, Département de Mycologie, Paris, France
| | - Joaquín Ariño
- Institut de Biotecnologia i Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain
| | - Óscar Zaragoza
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
- * E-mail:
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Qi T, Zhu X, Tan C, Liu P, Guo J, Kang Z, Guo J. Host-induced gene silencing of an important pathogenicity factor PsCPK1 in Puccinia striiformis f. sp. tritici enhances resistance of wheat to stripe rust. PLANT BIOTECHNOLOGY JOURNAL 2018; 16:797-807. [PMID: 28881438 PMCID: PMC5814584 DOI: 10.1111/pbi.12829] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2017] [Revised: 08/13/2017] [Accepted: 08/23/2017] [Indexed: 05/18/2023]
Abstract
Rust fungi are devastating plant pathogens and cause a large economic impact on wheat production worldwide. To overcome this rapid loss of resistance in varieties, we generated stable transgenic wheat plants expressing short interfering RNAs (siRNAs) targeting potentially vital genes of Puccinia striiformis f. sp. tritici (Pst). Protein kinase A (PKA) has been proved to play important roles in regulating the virulence of phytopathogenic fungi. PsCPK1, a PKA catalytic subunit gene from Pst, is highly induced at the early infection stage of Pst. The instantaneous silencing of PsCPK1 by barley stripe mosaic virus (BSMV)-mediated host-induced gene silencing (HIGS) results in a significant reduction in the length of infection hyphae and disease phenotype. These results indicate that PsCPK1 is an important pathogenicity factor by regulating Pst growth and development. Two transgenic lines expressing the RNA interference (RNAi) construct in a normally susceptible wheat cultivar displayed high levels of stable and consistent resistance to Pst throughout the T3 to T4 generations. The presence of the interfering RNAs in transgenic wheat plants was confirmed by northern blotting, and these RNAs were found to efficiently down-regulate PsCPK1 expression in wheat. This study addresses important aspects for the development of fungal-derived resistance through the expression of silencing constructs in host plants as a powerful strategy to control cereal rust diseases.
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Affiliation(s)
- Tuo Qi
- State Key Laboratory of Crop Stress Biology for Arid AreasCollege of Plant ProtectionNorthwest A&F UniversityYanglingShaanxiChina
| | - Xiaoguo Zhu
- State Key Laboratory of Crop Stress Biology for Arid AreasCollege of Plant ProtectionNorthwest A&F UniversityYanglingShaanxiChina
| | - Chenlong Tan
- State Key Laboratory of Crop Stress Biology for Arid AreasCollege of Plant ProtectionNorthwest A&F UniversityYanglingShaanxiChina
| | - Peng Liu
- State Key Laboratory of Crop Stress Biology for Arid AreasCollege of Plant ProtectionNorthwest A&F UniversityYanglingShaanxiChina
| | - Jia Guo
- State Key Laboratory of Crop Stress Biology for Arid AreasCollege of Plant ProtectionNorthwest A&F UniversityYanglingShaanxiChina
| | - Zhensheng Kang
- State Key Laboratory of Crop Stress Biology for Arid AreasCollege of Plant ProtectionNorthwest A&F UniversityYanglingShaanxiChina
| | - Jun Guo
- State Key Laboratory of Crop Stress Biology for Arid AreasCollege of Plant ProtectionNorthwest A&F UniversityYanglingShaanxiChina
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21
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Basso V, d'Enfert C, Znaidi S, Bachellier-Bassi S. From Genes to Networks: The Regulatory Circuitry Controlling Candida albicans Morphogenesis. Curr Top Microbiol Immunol 2018; 422:61-99. [PMID: 30368597 DOI: 10.1007/82_2018_144] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Candida albicans is a commensal yeast of most healthy individuals, but also one of the most prevalent human fungal pathogens. During adaptation to the mammalian host, C. albicans encounters different niches where it is exposed to several types of stress, including oxidative, nitrosative (e.g., immune system), osmotic (e.g., kidney and oral cavity) stresses and pH variation (e.g., gastrointestinal (GI) tract and vagina). C. albicans has developed the capacity to respond to the environmental changes by modifying its morphology, which comprises the yeast-to-hypha transition, white-opaque switching, and chlamydospore formation. The yeast-to-hypha transition has been very well characterized and was shown to be modulated by several external stimuli that mimic the host environment. For instance, temperature above 37 ℃, serum, alkaline pH, and CO2 concentration are all reported to enhance filamentation. The transition is characterized by the activation of an intricate regulatory network of signaling pathways, involving many transcription factors. The regulatory pathways that control either the stress response or morphogenesis are required for full virulence and promote survival of C. albicans in the host. Many of these transcriptional circuitries have been characterized, highlighting the complexity and the interconnections between the different pathways. Here, we present the major signaling pathways and the main transcription factors involved in the yeast-to-hypha transition. Furthermore, we describe the role of heat shock transcription factors in the morphogenetic transition, providing an edifying example of the complex cross talk between pathways involved in morphogenesis and stress response.
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Affiliation(s)
- Virginia Basso
- Unité Biologie et Pathogénicité Fongiques, Institut Pasteur, INRA, 25 Rue Du Docteur Roux, 75015, Paris, France.,Univ. Paris Diderot, Sorbonne Paris Cité, Cellule Pasteur, 25 Rue Du Docteur Roux, Paris, France.,Department of Pathology and Laboratory Medicine, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Christophe d'Enfert
- Unité Biologie et Pathogénicité Fongiques, Institut Pasteur, INRA, 25 Rue Du Docteur Roux, 75015, Paris, France
| | - Sadri Znaidi
- Unité Biologie et Pathogénicité Fongiques, Institut Pasteur, INRA, 25 Rue Du Docteur Roux, 75015, Paris, France. .,Institut Pasteur de Tunis, University of Tunis El Manar, Laboratoire de Microbiologie Moléculaire, Vaccinologie et Développement Biotechnologique, 13 Place Pasteur, 1002, Tunis-Belvédère, Tunisia.
| | - Sophie Bachellier-Bassi
- Unité Biologie et Pathogénicité Fongiques, Institut Pasteur, INRA, 25 Rue Du Docteur Roux, 75015, Paris, France.
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22
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Abstract
Cryptococcus neoformans is a human pathogenic yeast that causes hundreds of thousands of deaths worldwide among susceptible individuals, in particular, HIV+ patients. This yeast has developed several adaptation mechanisms that allow replication within the host. During decades, this yeast has been well known for a very peculiar and unique structure that contributes to virulence, a complex polysaccharide capsule that surrounds the cell wall. In contrast to other fungal pathogens, such as Candida albicans or Aspergillus fumigatus, the role of morphological transitions has not been studied in the virulence of Cryptococcus neoformans since this yeast does not form hyphae during infection. However, in the last years, different groups have described the ability of this fungus to change its size during infection. In particular, Cryptococcus can form "titan cells," which are blastoconidia of an abnormal large size. Since their discovery, there is increasing evidence that these cells contribute, not only to long-term persistence in the host, but they can also actively participate in the development of the disease. Recently, several groups have simultaneously described different media that induce the appearance of titan cells in laboratory conditions. Using these conditions, new inducing factors and signaling pathways involved in this transition have been described. In this article, we will review the main phenotypic features of these cells, factors, and transduction pathways that induce cell growth, and how titan cells contribute to the disease caused by this pathogen.
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23
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Shapiro RS, Chavez A, Porter CBM, Hamblin M, Kaas CS, DiCarlo JE, Zeng G, Xu X, Revtovich AV, Kirienko NV, Wang Y, Church GM, Collins JJ. A CRISPR-Cas9-based gene drive platform for genetic interaction analysis in Candida albicans. Nat Microbiol 2018; 3:73-82. [PMID: 29062088 PMCID: PMC5832965 DOI: 10.1038/s41564-017-0043-0] [Citation(s) in RCA: 97] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 09/15/2017] [Indexed: 11/09/2022]
Abstract
Candida albicans is the leading cause of fungal infections; yet, complex genetic interaction analysis remains cumbersome in this diploid pathogen. Here, we developed a CRISPR-Cas9-based 'gene drive array' platform to facilitate efficient genetic analysis in C. albicans. In our system, a modified DNA donor molecule acts as a selfish genetic element, replaces the targeted site and propagates to replace additional wild-type loci. Using mating-competent C. albicans haploids, each carrying a different gene drive disabling a gene of interest, we are able to create diploid strains that are homozygous double-deletion mutants. We generate double-gene deletion libraries to demonstrate this technology, targeting antifungal efflux and biofilm adhesion factors. We screen these libraries to identify virulence regulators and determine how genetic networks shift under diverse conditions. This platform transforms our ability to perform genetic interaction analysis in C. albicans and is readily extended to other fungal pathogens.
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Affiliation(s)
- Rebecca S Shapiro
- Department of Biological Engineering, Institute for Medical Engineering and Science, Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, 02115, USA
| | - Alejandro Chavez
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, 02115, USA
- Department of Pathology, Massachusetts General Hospital, Boston, MA, 02114, USA
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, 02115, USA
- Department of Pathology and Cell Biology, Columbia University College of Physicians and Surgeons, New York, 10032, NY, USA
| | - Caroline B M Porter
- Department of Biological Engineering, Institute for Medical Engineering and Science, Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA
| | - Meagan Hamblin
- Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA
| | - Christian S Kaas
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, 02115, USA
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, 02115, USA
- Department of Expression Technologies 2, Novo Nordisk A/S, Maaloev, 2760, Denmark
| | - James E DiCarlo
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, 02115, USA
- Department of Ophthalmology, Columbia University, New York, NY, 10032, USA
| | - Guisheng Zeng
- Institute of Molecular and Cell Biology, Agency for Science, Technology & Research, 61 Biopolis Drive (Proteos), Singapore, 138673, Singapore
| | - Xiaoli Xu
- Institute of Molecular and Cell Biology, Agency for Science, Technology & Research, 61 Biopolis Drive (Proteos), Singapore, 138673, Singapore
| | | | | | - Yue Wang
- Institute of Molecular and Cell Biology, Agency for Science, Technology & Research, 61 Biopolis Drive (Proteos), Singapore, 138673, Singapore
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117549, Singapore
| | - George M Church
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, 02115, USA.
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, 02115, USA.
| | - James J Collins
- Department of Biological Engineering, Institute for Medical Engineering and Science, Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
- Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA.
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, 02115, USA.
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24
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Adnan M, Zheng W, Islam W, Arif M, Abubakar YS, Wang Z, Lu G. Carbon Catabolite Repression in Filamentous Fungi. Int J Mol Sci 2017; 19:ijms19010048. [PMID: 29295552 PMCID: PMC5795998 DOI: 10.3390/ijms19010048] [Citation(s) in RCA: 114] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2017] [Revised: 12/13/2017] [Accepted: 12/20/2017] [Indexed: 12/18/2022] Open
Abstract
Carbon Catabolite Repression (CCR) has fascinated scientists and researchers around the globe for the past few decades. This important mechanism allows preferential utilization of an energy-efficient and readily available carbon source over relatively less easily accessible carbon sources. This mechanism helps microorganisms to obtain maximum amount of glucose in order to keep pace with their metabolism. Microorganisms assimilate glucose and highly favorable sugars before switching to less-favored sources of carbon such as organic acids and alcohols. In CCR of filamentous fungi, CreA acts as a transcription factor, which is regulated to some extent by ubiquitination. CreD-HulA ubiquitination ligase complex helps in CreA ubiquitination, while CreB-CreC deubiquitination (DUB) complex removes ubiquitin from CreA, which causes its activation. CCR of fungi also involves some very crucial elements such as Hexokinases, cAMP, Protein Kinase (PKA), Ras proteins, G protein-coupled receptor (GPCR), Adenylate cyclase, RcoA and SnfA. Thorough study of molecular mechanism of CCR is important for understanding growth, conidiation, virulence and survival of filamentous fungi. This review is a comprehensive revision of the regulation of CCR in filamentous fungi as well as an updated summary of key regulators, regulation of different CCR-dependent mechanisms and its impact on various physical characteristics of filamentous fungi.
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Affiliation(s)
- Muhammad Adnan
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
- Key Laboratory of Bio-Pesticides and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Wenhui Zheng
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
- Key Laboratory of Bio-Pesticides and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Waqar Islam
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Muhammad Arif
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Yakubu Saddeeq Abubakar
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
- Key Laboratory of Bio-Pesticides and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Zonghua Wang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
- Key Laboratory of Bio-Pesticides and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Guodong Lu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
- Key Laboratory of Bio-Pesticides and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
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25
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Hanson SJ, Byrne KP, Wolfe KH. Flip/flop mating-type switching in the methylotrophic yeast Ogataea polymorpha is regulated by an Efg1-Rme1-Ste12 pathway. PLoS Genet 2017; 13:e1007092. [PMID: 29176810 PMCID: PMC5720833 DOI: 10.1371/journal.pgen.1007092] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 12/07/2017] [Accepted: 10/31/2017] [Indexed: 01/01/2023] Open
Abstract
In haploid cells of Ogataea (Hansenula) polymorpha an environmental signal, nitrogen starvation, induces a reversible change in the structure of a chromosome. This process, mating-type switching, inverts a 19-kb DNA region to place either MATa or MATα genes under centromeric repression of transcription, depending on the orientation of the region. Here, we investigated the genetic pathway that controls switching. We characterized the transcriptomes of haploid and diploid O. polymorpha by RNAseq in rich and nitrogen-deficient media, and found that there are no constitutively a-specific or α-specific genes other than the MAT genes themselves. We mapped a switching defect in a sibling species (O. parapolymorpha strain DL-1) by interspecies bulk segregant analysis to a frameshift in the transcription factor EFG1, which in Candida albicans regulates filamentous growth and white-opaque switching. Gene knockout, overexpression and ChIPseq experiments show that EFG1 regulates RME1, which in turn regulates STE12, to achieve mating-type switching. All three genes are necessary both for switching and for mating. Overexpression of RME1 or STE12 is sufficient to induce switching without a nitrogen depletion signal. The homologous recombination genes RAD51 and RAD17 are also necessary for switching. The pathway controlling switching in O. polymorpha shares no components with the regulation of HO in S. cerevisiae, which does not involve any environmental signal, but it shares some components with mating-type switching in Kluyveromyces lactis and with white-opaque phenotypic switching in C. albicans. The molecular mechanisms of self-fertility (homothallism) vary enormously among fungal species. We previously found that in the yeast Ogataea polymorpha, homothallism is achieved by a novel mating-type switching mechanism that exchanges the locations of MATa and MATα genes between expression and repression contexts. Switching in this species is induced by nitrogen depletion, unlike the analogous process in Saccharomyces cerevisiae. Here, we show that the upstream parts of the genetic pathway controlling the environmental induction of switching in O. polymorpha are the same as the environmental pathway that induces competence for mating in this species.
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Affiliation(s)
- Sara J. Hanson
- UCD Conway Institute, School of Medicine, University College Dublin, Dublin 4, Ireland
- Department of Molecular Biology, Colorado College, Colorado Springs, Colorado, United States of America
- * E-mail:
| | - Kevin P. Byrne
- UCD Conway Institute, School of Medicine, University College Dublin, Dublin 4, Ireland
| | - Kenneth H. Wolfe
- UCD Conway Institute, School of Medicine, University College Dublin, Dublin 4, Ireland
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26
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A Bimolecular Fluorescence Complementation Tool for Identification of Protein-Protein Interactions in Candida albicans. G3-GENES GENOMES GENETICS 2017; 7:3509-3520. [PMID: 28860184 PMCID: PMC5633398 DOI: 10.1534/g3.117.300149] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Investigation of protein-protein interactions (PPI) in Candida albicans is essential for understanding the regulation of the signal transduction network that triggers its pathogenic lifestyle. Unique features of C. albicans, such as its alternative codon usage and incomplete meiosis, have enforced the optimization of standard genetic methods as well as development of novel approaches. Since the existing methods for detection of PPI are limited for direct visualization of the interacting complex in vivo, we have established a bimolecular fluorescence complementation (BiFC) assay in C. albicans, a powerful technique for studying PPI. We have developed an optimized set of plasmids that allows for N- and C-terminal tagging of proteins with split yeast-enhanced monomeric Venus fragments, so that all eight combinations of fusion orientations can be analyzed. With the use of our BiFC assay we demonstrate three interaction complexes in vivo, which were also confirmed by two-hybrid analysis. Our Candida-optimized BiFC assay represents a useful molecular tool for PPI studies and shows great promise in expanding our knowledge of molecular mechanisms of protein functions.
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27
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A novel connection between the Cell Wall Integrity and the PKA pathways regulates cell wall stress response in yeast. Sci Rep 2017; 7:5703. [PMID: 28720901 PMCID: PMC5515849 DOI: 10.1038/s41598-017-06001-9] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 06/13/2017] [Indexed: 12/22/2022] Open
Abstract
Fungal cells trigger adaptive mechanisms to survive in situations that compromise cell wall integrity. We show here that the global transcriptional response elicited by inhibition of the synthesis of β-1,3-glucan by caspofungin, encompasses a set of genes that are dependent on Slt2, the MAPK of the Cell Wall Integrity (CWI) pathway, and a broad group of genes regulated independently of Slt2. Genes negatively regulated by the cyclic AMP/Protein Kinase A (PKA) signaling pathway were overrepresented in the latter group. Moreover, cell wall stress mediated by inhibition of β-1,3-glucan synthesis, but not by other cell wall interfering compounds, negatively regulated PKA signaling as indicated by the nuclear localisation of Msn2, cellular glycogen accumulation, a decrease of intracellular cAMP levels and a severe decrease in both the activation of the small GTPase Ras2 and the phosphorylation of known substrates of PKA. All these effects relied on the plasma membrane-spanning sensor of the CWI pathway Wsc1. In addition, caspofungin induced a reduction in the cytosolic pH, which was dependent on the extracellular region of Wsc1. Therefore, alterations of the β-1,3-glucan network in the fungal cell wall, induce, through Wsc1, the activation of the CWI pathway and parallel inhibition of PKA signaling.
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28
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Selvaraj P, Tham HF, Ramanujam R, Naqvi NI. Subcellular compartmentation, interdependency and dynamics of the cyclic AMP-dependent PKA subunits during pathogenic differentiation in rice blast. Mol Microbiol 2017; 105:484-504. [PMID: 28544028 DOI: 10.1111/mmi.13713] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/16/2017] [Indexed: 02/03/2023]
Abstract
The cAMP-dependent PKA signalling plays a central role in growth, asexual development and pathogenesis in fungal pathogens. Here, we functionally characterised RPKA, the regulatory subunit of cAMP/PKA and studied the dynamics and organisation of the PKA subunits in the rice blast pathogen Magnaporthe oryzae. The RPKA subunit was essential for proper vegetative growth, asexual sporulation and surface hydrophobicity in M. oryzae. A spontaneous suppressor mutation, SMR19, that restored growth and conidiation in the RPKA deletion mutant was isolated and characterised. SMR19 enhanced conidiation and appressorium formation but failed to suppress the pathogenesis defects in rpkAΔ. The PKA activity was undetectable in the mycelial extracts of SMR19, which showed a single mutation (val242leu) in the highly conserved active site of the catalytic subunit (CPKA) of cAMP/PKA. The two subunits of cAMP/PKA showed different subcellular localisation patterns with RpkA being predominantly nucleocytoplasmic in conidia, while CpkA was largely cytosolic and/or vesicular. The CpkA anchored RpkA in cytoplasmic vesicles, and localisation of PKA in the cytoplasm was governed by CpkA in a cAMP-dependant or independent manner. We show that there exists a tight regulation of PKA subunits at the level of transcription, and the cAMP signalling is differentially compartmentalised in a stage-specific manner in rice blast.
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Affiliation(s)
- Poonguzhali Selvaraj
- Temasek Life Sciences Laboratory and Department of Biological Sciences, 1 Research Link, National University of Singapore, Singapore
| | - Hong Fai Tham
- School of Applied Science, Temasek Polytechnic, Singapore
| | - Ravikrishna Ramanujam
- Temasek Life Sciences Laboratory and Department of Biological Sciences, 1 Research Link, National University of Singapore, Singapore
| | - Naweed I Naqvi
- Temasek Life Sciences Laboratory and Department of Biological Sciences, 1 Research Link, National University of Singapore, Singapore.,School of Biological Sciences, Nanyang Technological University, Singapore
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29
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Cao C, Wu M, Bing J, Tao L, Ding X, Liu X, Huang G. Global regulatory roles of the c
AMP/PKA
pathway revealed by phenotypic, transcriptomic and phosphoproteomic analyses in a null mutant of the
PKA
catalytic subunit in
C
andida albicans. Mol Microbiol 2017; 105:46-64. [DOI: 10.1111/mmi.13681] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/27/2017] [Indexed: 01/30/2023]
Affiliation(s)
- Chengjun Cao
- State Key Laboratory of Mycology, Institute of MicrobiologyChinese Academy of SciencesBeijing100101 China
- University of Chinese Academy of SciencesBeijing100049 China
| | - Mei Wu
- Institute of Analytical Chemistry and Synthetic and Functional Biomolecules Center, College of Chemistry and Molecular EngineeringPeking UniversityBeijing100871 China
| | - Jian Bing
- State Key Laboratory of Mycology, Institute of MicrobiologyChinese Academy of SciencesBeijing100101 China
| | - Li Tao
- State Key Laboratory of Mycology, Institute of MicrobiologyChinese Academy of SciencesBeijing100101 China
| | - Xuefen Ding
- State Key Laboratory of Mycology, Institute of MicrobiologyChinese Academy of SciencesBeijing100101 China
- University of Chinese Academy of SciencesBeijing100049 China
| | - Xiaoyun Liu
- Institute of Analytical Chemistry and Synthetic and Functional Biomolecules Center, College of Chemistry and Molecular EngineeringPeking UniversityBeijing100871 China
| | - Guanghua Huang
- State Key Laboratory of Mycology, Institute of MicrobiologyChinese Academy of SciencesBeijing100101 China
- University of Chinese Academy of SciencesBeijing100049 China
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30
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Fernández Núñez L, Ocampo J, Gottlieb AM, Rossi S, Moreno S. Multiple isoforms for the catalytic subunit of PKA in the basal fungal lineage Mucor circinelloides. Fungal Biol 2016; 120:1493-1508. [PMID: 27890086 DOI: 10.1016/j.funbio.2016.07.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Revised: 06/20/2016] [Accepted: 07/21/2016] [Indexed: 12/18/2022]
Abstract
Protein kinase A (PKA) activity is involved in dimorphism of the basal fungal lineage Mucor. From the recently sequenced genome of Mucor circinelloides we could predict ten catalytic subunits of PKA. From sequence alignment and structural prediction we conclude that the catalytic core of the isoforms is conserved, and the difference between them resides in their amino termini. This high number of isoforms is maintained in the subdivision Mucoromycotina. Each paralogue, when compared to the ones form other fungi is more homologous to one of its orthologs than to its paralogs. All of these fungal isoforms cannot be included in the class I or II in which fungal protein kinases have been classified. mRNA levels for each isoform were measured during aerobic and anaerobic growth. The expression of each isoform is differential and associated to a particular growth stage. We reanalyzed the sequence of PKAC (GI 20218944), the only cloned sequence available until now for a catalytic subunit of M. circinelloides. PKAC cannot be classified as a PKA because of its difference in the conserved C-tail; it shares with PKB a conserved C2 domain in the N-terminus. No catalytic activity could be measured for this protein nor predicted bioinformatically. It can thus be classified as a pseudokinase. Its importance can not be underestimated since it is expressed at the mRNA level in different stages of growth, and its deletion is lethal.
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Affiliation(s)
- Lucas Fernández Núñez
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IQUIBICEN-CONICET, Intendente Güiraldes 2160 - Ciudad Universitaria - C1428EGA, Buenos Aires, Argentina
| | - Josefina Ocampo
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IQUIBICEN-CONICET, Intendente Güiraldes 2160 - Ciudad Universitaria - C1428EGA, Buenos Aires, Argentina
| | - Alexandra M Gottlieb
- Departamento de Ecologia, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IEGEBA-CONICET, Intendente Güiraldes 2160 - Ciudad Universitaria - C1428EGA, Buenos Aires, Argentina
| | - Silvia Rossi
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IQUIBICEN-CONICET, Intendente Güiraldes 2160 - Ciudad Universitaria - C1428EGA, Buenos Aires, Argentina
| | - Silvia Moreno
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IQUIBICEN-CONICET, Intendente Güiraldes 2160 - Ciudad Universitaria - C1428EGA, Buenos Aires, Argentina.
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31
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Binder U, Benčina M, Fizil Á, Batta G, Chhillar AK, Marx F. Protein kinase A signaling and calcium ions are major players in PAF mediated toxicity against Aspergillus niger. FEBS Lett 2015; 589:1266-71. [PMID: 25882631 PMCID: PMC4424949 DOI: 10.1016/j.febslet.2015.03.037] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Revised: 03/27/2015] [Accepted: 03/30/2015] [Indexed: 11/16/2022]
Abstract
Aspergillus niger is highly susceptible to the antifungal protein PAF. Ca2+ and cAMP/PKA signalling are interconnected in response to PAF. PAF toxicity requires the activation of the cAMP/PkaA signaling cascade. PAF evokes a sustained increase in the [Ca2+]c resting level. Only a functional PAF protein interferes with the fungal Ca2+ homeostasis. PAF represents a promising molecule to develop new antifungal strategies.
The Penicillium chrysogenum antifungal protein PAF is toxic against potentially pathogenic Ascomycetes. We used the highly sensitive aequorin-expressing model Aspergillus niger to identify a defined change in cytoplasmic free Ca2+ dynamics in response to PAF. This Ca2+ signature depended on an intact positively charged lysine-rich PAF motif. By combining Ca2+ measurements in A. niger mutants with deregulated cAMP/protein kinase A (PKA) signaling, we proved the interconnection of Ca2+ perturbation and cAMP/PKA signaling in the mechanistic function of PAF. A deep understanding of the mode of action of PAF is an invaluable prerequisite for its future application as new antifungal drug.
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Affiliation(s)
- Ulrike Binder
- Biocenter, Division of Molecular Biology, Medical University of Innsbruck, Innrain 80, A-6020 Innsbruck, Austria; Division of Hygiene and Medical Microbiology, Schöpfstrasse 41, Medical University of Innsbruck, A-6020 Innsbruck, Austria
| | - Mojca Benčina
- Department of Biotechnology, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia
| | - Ádám Fizil
- Department of Organic Chemistry, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary
| | - Gyula Batta
- Department of Organic Chemistry, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary
| | - Anil K Chhillar
- Biocenter, Division of Molecular Biology, Medical University of Innsbruck, Innrain 80, A-6020 Innsbruck, Austria; Centre for Biotechnology, Maharshi Dayanand University, IN-124001 Rohtak, Haryana, India
| | - Florentine Marx
- Biocenter, Division of Molecular Biology, Medical University of Innsbruck, Innrain 80, A-6020 Innsbruck, Austria.
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Developmental Growth Control Exerted via the Protein A Kinase Tpk2 in Ashbya gossypii. EUKARYOTIC CELL 2015; 14:593-601. [PMID: 25862153 DOI: 10.1128/ec.00045-15] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 04/03/2015] [Indexed: 01/18/2023]
Abstract
Sporulation in Ashbya gossypii is induced by nutrient-limited conditions and leads to the formation of haploid spores. Using RNA-seq, we have determined a gene set induced upon sporulation, which bears considerable overlap with that of Saccharomyces cerevisiae but also contains A. gossypii-specific genes. Addition of cyclic AMP (cAMP) to nutrient-limited media blocks sporulation and represses the induction of sporulation specific genes. Deletion of the protein kinase A (PKA) catalytic subunits encoded by TPK1 and TPK2 showed reduced growth in tpk1 but enhanced growth in the tpk2 strain; however, both mutants sporulated well. Sporulation can be blocked by cAMP in tpk1 but not in tpk2 strains. Similarly, TPK2 acts at a second developmental switch promoting the break in spore dormancy. In S. cerevisiae, PKA phosphorylates and inhibits Msn2/4. The transcript profiles of the tpk1 and msn2/4 mutants were very similar to that of the wild type under sporulation conditions. However, deletion of the single A. gossypii MSN2/4 homolog generated a specific sporulation defect. We identified a set of genes involved in spore wall assembly that was downregulated in the msn2/4 mutant, particularly DIT2, suggesting that poor spore viability may be due to lysis of spores. Our results reveal specific functional differences between the two catalytic PKA subunits in A. gossypii and identified Tpk2 as the key A kinase that transduces developmental decisions of growth. Our data also suggest that Msn2/4 is involved only at a late step of sporulation in A. gossypii and is not a major regulator of IME1.
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Systematic identification of signal integration by protein kinase A. Proc Natl Acad Sci U S A 2015; 112:4501-6. [PMID: 25831502 DOI: 10.1073/pnas.1409938112] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Cellular processes and homeostasis control in eukaryotic cells is achieved by the action of regulatory proteins such as protein kinase A (PKA). Although the outbound signals from PKA directed to processes such as metabolism, growth, and aging have been well charted, what regulates this conserved regulator remains to be systematically identified to understand how it coordinates biological processes. Using a yeast PKA reporter assay, we identified genes that influence PKA activity by measuring protein-protein interactions between the regulatory and the two catalytic subunits of the PKA complex in 3,726 yeast genetic-deletion backgrounds grown on two carbon sources. Overall, nearly 500 genes were found to be connected directly or indirectly to PKA regulation, including 80 core regulators, denoting a wide diversity of signals regulating PKA, within and beyond the described upstream linear pathways. PKA regulators span multiple processes, including the antagonistic autophagy and methionine biosynthesis pathways. Our results converge toward mechanisms of PKA posttranslational regulation by lysine acetylation, which is conserved between yeast and humans and that, we show, regulates protein complex formation in mammals and carbohydrate storage and aging in yeast. Taken together, these results show that the extent of PKA input matches with its output, because this kinase receives information from upstream and downstream processes, and highlight how biological processes are interconnected and coordinated by PKA.
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de Assis LJ, Ries LNA, Savoldi M, dos Reis TF, Brown NA, Goldman GH. Aspergillus nidulans protein kinase A plays an important role in cellulase production. BIOTECHNOLOGY FOR BIOFUELS 2015; 8:213. [PMID: 26690721 PMCID: PMC4683954 DOI: 10.1186/s13068-015-0401-1] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 11/30/2015] [Indexed: 05/17/2023]
Abstract
BACKGROUND The production of bioethanol from lignocellulosic feedstocks is dependent on lignocellulosic biomass degradation by hydrolytic enzymes. The main component of lignocellulose is cellulose and different types of organisms are able to secrete cellulases. The filamentous fungus Aspergillus nidulans serves as a model organism to study cellulase production and the available tools allow exploring more in depth the mechanisms governing cellulase production and carbon catabolite repression. RESULTS In A. nidulans, microarray data identified the cAMP-dependent protein kinase A (PkaA) as being involved in the transcriptional modulation and the production of lignocellulolytic enzymes in the presence of cellulose. Deletion of pkaA resulted in increased hydrolytic enzyme secretion, but reduced growth in the presence of lignocellulosic components and various other carbon sources. Furthermore, genes involved in fungal development were increased in the ΔpkaA strain, probably leading to the increased hyphal branching as was observed in this strain. This would allow the secretion of higher amounts of proteins. In addition, the expression of SynA, encoding a V-SNARE synaptobrevin protein involved in secretion, was increased in the ΔpkaA mutant. Deletion of pkaA also resulted in the reduced nuclear localization of the carbon catabolite repressor CreA in the presence of glucose and in partial de-repression when grown on cellulose. PkaA is involved in the glucose signaling pathway as the absence of this protein resulted in reduced glucose uptake and lower hexokinase/glucokinase activity, directing the cell to starvation conditions. Genome-wide transcriptomics showed that the expression of genes encoding proteins involved in fatty acid metabolism, mitochondrial function and in the use of cell storages was increased. CONCLUSIONS This study shows that PkaA is involved in hydrolytic enzyme production in A. nidulans. It appears that this protein kinase blocks the glucose pathway, hence forcing the cell to change to starvation conditions, increasing hydrolytic enzyme secretion and inducing the usage of cellular storages. This work uncovered new regulatory avenues governing the tight interplay between the metabolic states of the cell, which are important for the production of hydrolytic enzymes targeting lignocellulosic biomass. Deletion of pkaA resulted in a strain with increased hydrolytic enzyme secretion and reduced biomass formation.
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Affiliation(s)
- Leandro José de Assis
- />Departamento de Ciências Farmacêuticas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. do Café S/N, CEP 14040-903, Ribeirão Preto, São Paulo, Brazil
| | - Laure Nicolas Annick Ries
- />Departamento de Ciências Farmacêuticas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. do Café S/N, CEP 14040-903, Ribeirão Preto, São Paulo, Brazil
| | - Marcela Savoldi
- />Departamento de Ciências Farmacêuticas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. do Café S/N, CEP 14040-903, Ribeirão Preto, São Paulo, Brazil
| | - Thaila Fernanda dos Reis
- />Departamento de Ciências Farmacêuticas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. do Café S/N, CEP 14040-903, Ribeirão Preto, São Paulo, Brazil
| | - Neil Andrew Brown
- />Plant Biology and Crop Science, Rothamsted Research, Harpenden, Herts AL5 2JQ UK
| | - Gustavo Henrique Goldman
- />Departamento de Ciências Farmacêuticas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. do Café S/N, CEP 14040-903, Ribeirão Preto, São Paulo, Brazil
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Kusch S, Ahmadinejad N, Panstruga R, Kuhn H. In silico analysis of the core signaling proteome from the barley powdery mildew pathogen (Blumeria graminis f.sp. hordei). BMC Genomics 2014; 15:843. [PMID: 25277210 PMCID: PMC4195978 DOI: 10.1186/1471-2164-15-843] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Accepted: 09/24/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Compared to other ascomycetes, the barley powdery mildew pathogen Blumeria graminis f.sp. hordei (Bgh) has a large genome (ca. 120 Mbp) that harbors a relatively small number of protein-coding genes (ca. 6500). This genomic assemblage is thought to be the result of numerous gene losses, which likely represent an evolutionary adaptation to a parasitic lifestyle in close association with its host plant, barley (Hordeum vulgare). Approximately 8% of the Bgh genes are predicted to encode virulence effectors that are secreted into host tissue and/or cells to promote pathogenesis; the remaining proteome is largely uncharacterized at present. RESULTS We provide a comparative analysis of the conceptual Bgh proteome, with an emphasis on proteins with known roles in fungal development and pathogenicity, for example heterotrimeric G proteins and G protein coupled receptors; components of calcium and cAMP signaling; small monomeric GTPases; mitogen-activated protein cascades and transcription factors. The predicted Bgh proteome lacks a number of proteins that are otherwise conserved in filamentous fungi, including two proteins that are required for the formation of anastomoses (somatic hyphal connections). By contrast, apart from minor modifications, all major canonical signaling pathways are retained in Bgh. A family of kinases that preferentially occur in pathogenic species of the fungal clade Leotiomyceta is unusually expanded in Bgh and its close relative, Blumeria graminis f.sp. tritici. CONCLUSIONS Our analysis reveals characteristic features of the proteome of a fungal phytopathogen that occupies an extreme habitat: the living plant cell.
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Affiliation(s)
| | | | - Ralph Panstruga
- Unit of Plant Molecular Cell Biology, Institute for Biology I, RWTH Aachen University, Worringerweg 1, 52056 Aachen, Germany.
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Ortiz-Urquiza A, Keyhani NO. Stress response signaling and virulence: insights from entomopathogenic fungi. Curr Genet 2014; 61:239-49. [DOI: 10.1007/s00294-014-0439-9] [Citation(s) in RCA: 114] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 07/01/2014] [Accepted: 07/14/2014] [Indexed: 01/18/2023]
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Hu S, Zhou X, Gu X, Cao S, Wang C, Xu JR. The cAMP-PKA pathway regulates growth, sexual and asexual differentiation, and pathogenesis in Fusarium graminearum. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2014; 27:557-66. [PMID: 24450772 DOI: 10.1094/mpmi-10-13-0306-r] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Like many other filamentous ascomycetes, Fusarium graminearum contains two genes named CPK1 and CPK2 that encode the catalytic subunits of cyclic AMP (cAMP)-dependent protein kinase A (PKA). To determine the role of cAMP signaling in pathogenesis and development in F. graminearum, we functionally characterized these two genes. In addition, we generated and characterized the cpk1 cpk2 double and fac1 adenylate cyclase gene deletion mutants. The cpk1 mutant was significantly reduced in vegetative growth, conidiation, and deoxynivalenol production but it had increased tolerance to elevated temperatures. It was defective in the production of penetration branches on plant surfaces, colonization of wheat rachises, and spreading in flowering wheat heads. Deletion of CPK1 had no effect on perithecium development but the cpk1 mutant was defective in ascospore maturation and releasing. In contrast, the cpk2 mutant had no detectable phenotypes, suggesting that CPK2 contributes minimally to PKA activities in F. graminearum. Nevertheless, the cpk1 cpk2 double mutant had more severe defects in vegetative growth and rarely produced morphologically abnormal conidia. The double mutant, unlike the cpk1 or cpk2 mutant, was nonpathogenic and failed to form perithecia on self-mating plates. Therefore, CPK1 and CPK2 must have overlapping functions in vegetative growth, differentiation, and plant infection in F. graminearum. The fac1 mutant was also nonpathogenic and had growth defects similar to those of the cpk1 cpk2 mutant. However, deletion of FAC1 had no effect on conidium morphology. These results indicated that CPK1 is the major PKA catalytic subunit gene and that the cAMP-PKA pathway plays critical roles in hyphal growth, conidiation, ascosporogenesis, and plant infection in F. graminearum.
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