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Kang YS, Jung J, Brown H, Mateusiak C, Doering TL, Brent MR. How host-like signals drive gene expression and capsule expansion in Cryptococcus neoformans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.04.19.537239. [PMID: 37131703 PMCID: PMC10153387 DOI: 10.1101/2023.04.19.537239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Cryptococcus neoformans is an opportunistic fungal pathogen with a polysaccharide capsule that becomes greatly enlarged in the mammalian host and during in vitro growth under host-like conditions. To understand how individual environmental signals affect capsule size and gene expression, we grew cells in all combinations of five signals implicated in capsule size and systematically measured cell and capsule sizes. We also sampled these cultures over time and performed RNA-Seq in quadruplicate, yielding 881 RNA-Seq samples. Analysis of the resulting data sets showed that capsule induction in tissue culture medium, typically used to represent host-like conditions, requires the presence of either CO2 or exogenous cyclic AMP (cAMP). Surprisingly, adding either of these pushes overall gene expression in the opposite direction from tissue culture media alone, even though both are required for capsule development. Another unexpected finding was that rich medium blocks capsule growth completely. Statistical analysis further revealed many genes whose expression is associated with capsule thickness; deletion of one of these significantly reduced capsule size. Beyond illuminating capsule induction, our massive, uniformly collected dataset will be a significant resource for the research community.
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Affiliation(s)
- Yu Sung Kang
- These authors contributed equally
- Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO 63110
- Department of Computer Science and Engineering, Washington University, St. Louis, MO 63108
| | - Jeffery Jung
- These authors contributed equally
- Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO 63110
- Department of Computer Science and Engineering, Washington University, St. Louis, MO 63108
| | - Holly Brown
- Department of Computer Science and Engineering, Washington University, St. Louis, MO 63108
| | - Chase Mateusiak
- Department of Computer Science and Engineering, Washington University, St. Louis, MO 63108
| | - Tamara L. Doering
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110
| | - Michael R. Brent
- Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO 63110
- Department of Computer Science and Engineering, Washington University, St. Louis, MO 63108
- Department of Genetics, Washington University School of Medicine, St. Louis, MO 63110
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2
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Navale AM. Glucose Transporter and Sensor Mechanisms in Fungal Pathogens as Potential Drug Targets. Curr Rev Clin Exp Pharmacol 2024; 19:250-258. [PMID: 37861001 DOI: 10.2174/0127724328263050230923154326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 08/02/2023] [Accepted: 08/25/2023] [Indexed: 10/21/2023]
Abstract
Fungal infections are emerging as major health challenges in recent years. The development of resistance against existing antifungal agents needs urgent attention and action. The limited classes of antifungal drugs available, their tendency to cause adverse effects, lack of effectiveness, etc., are the major limitations of current therapy. Thus, there is a pressing demand for new antifungal drug classes to cope with the present circumstances. Glucose is the key source of energy for all organisms, including fungi. Glucose plays a crucial role as a source of carbon and energy for processes like virulence, growth, invasion, biofilm formation, and resistance development. The glucose transport and sensing mechanisms are well developed in these organisms as an important strategy to sustain survival. Modulating these transport or sensor mechanisms may serve as an important strategy to inhibit fungal growth. Moreover, the structural difference between human and fungal glucose transporters makes them more appealing as drug targets. Limited literature is available for fungal glucose entry mechanisms. This review provides a comprehensive account of sugar transport mechanisms in common fungal pathogens.
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Affiliation(s)
- Archana Mohit Navale
- Department of Pharmacology, Parul Institute of Pharmacy, Parul University, Limda, India
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3
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Ding M, Cao S, Xu D, Xia A, Wang Z, Wang W, Duan K, Wu C, Wang Q, Liang J, Wang D, Liu H, Xu JR, Jiang C. A non-pheromone GPCR is essential for meiosis and ascosporogenesis in the wheat scab fungus. Proc Natl Acad Sci U S A 2023; 120:e2313034120. [PMID: 37812726 PMCID: PMC10589705 DOI: 10.1073/pnas.2313034120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Accepted: 09/08/2023] [Indexed: 10/11/2023] Open
Abstract
Meiosis is essential for generating genetic diversity and sexual spores, but the regulation of meiosis and ascosporogenesis is not clear in filamentous fungi, in which dikaryotic and diploid cells formed inside fruiting bodies are not free living and independent of pheromones or pheromone receptors. In this study, Gia1, a non-pheromone GPCR (G protein-coupled receptor) with sexual-specific expression in Fusarium graminearum, is found to be essential for ascosporogenesis. The gia1 mutant was normal in perithecium development, crozier formation, and karyogamy but failed to undergo meiosis, which could be partially rescued by a dominant active mutation in GPA1 and activation of the Gpmk1 pathway. GIA1 orthologs have conserved functions in regulating meiosis and ascosporogenesis in Sordariomycetes. GIA1 has a paralog, GIP1, in F. graminearum and other Hypocreales species which is essential for perithecium formation. GIP1 differed from GIA1 in expression profiles and downstream signaling during sexual reproduction. Whereas the C-terminal tail and IR3 were important for intracellular signaling, the N-terminal region and EL3 of Gia1 were responsible for recognizing its ligand, which is likely a protein enriched in developing perithecia, particularly in the gia1 mutant. Taken together, these results showed that GIA1 encodes a non-pheromone GPCR that regulates the entry into meiosis and ascosporogenesis via the downstream Gpmk1 MAP kinase pathway in F. graminearum and other filamentous ascomycetes.
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Affiliation(s)
- Mingyu Ding
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang, Shaanxi712100, China
| | - Shulin Cao
- Institute of Plant Protection, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, Nanjing, Jiangsu210014, China
| | - Daiying Xu
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang, Shaanxi712100, China
| | - Aliang Xia
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang, Shaanxi712100, China
| | - Zeyi Wang
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN47907
| | - Wanshan Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang, Shaanxi712100, China
| | - Kaili Duan
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang, Shaanxi712100, China
| | - Chenyu Wu
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang, Shaanxi712100, China
| | - Qinhu Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang, Shaanxi712100, China
| | - Jie Liang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang, Shaanxi712100, China
| | - Diwen Wang
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN47907
| | - Huiquan Liu
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang, Shaanxi712100, China
| | - Jin-Rong Xu
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN47907
| | - Cong Jiang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang, Shaanxi712100, China
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Hilbert ZA, Bednarek JM, Schwiesow MJW, Chung KY, Moreau CT, Brown JCS, Elde NC. Distinct pathways of adaptive evolution in Cryptococcus neoformans reveal a mutation in adenylyl cyclase with trade-offs for pathogenicity. Curr Biol 2023; 33:4136-4149.e9. [PMID: 37708888 PMCID: PMC10592076 DOI: 10.1016/j.cub.2023.08.054] [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: 04/06/2023] [Revised: 07/13/2023] [Accepted: 08/17/2023] [Indexed: 09/16/2023]
Abstract
Pathogenic fungi populate a wide range of environments and infect a diversity of host species. Despite this substantial biological flexibility, the impact of interactions between fungi and their hosts on the evolution of pathogenicity remains unclear. We studied how repeated interactions between the fungus Cryptococcus neoformans and relevant environmental and mammalian host cells-amoeba and mouse macrophages-shape the evolution of this model fungal pathogen. First, using a collection of clinical and environmental isolates of C. neoformans, we characterized a range of survival phenotypes for these strains when exposed to host cells of different species. We then performed serial passages of an environmentally isolated C. neoformans strain through either amoeba or macrophages for ∼75 generations to observe how these interactions select for improved replication within hosts. In one adapted population, we identified a single point mutation in the adenylyl cyclase gene, CAC1, that swept to fixation and confers a strong competitive advantage for growth inside macrophages. Strikingly, this growth advantage in macrophages is inversely correlated with disease severity during mouse infections, suggesting that adaptation to specific host niches can markedly reduce the pathogenicity of these fungi. These results raise intriguing questions about the influence of cyclic AMP (cAMP) signaling on pathogenicity and highlight the role of seemingly small adaptive changes in promoting fundamental shifts in the intracellular behavior and virulence of these important human pathogens.
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Affiliation(s)
- Zoë A Hilbert
- Department of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA; Howard Hughes Medical Institute, University of Utah School of Medicine, Salt Lake City, UT 84112, USA.
| | - Joseph M Bednarek
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Mara J W Schwiesow
- Department of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA; Howard Hughes Medical Institute, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Krystal Y Chung
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Christian T Moreau
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Jessica C S Brown
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Nels C Elde
- Department of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA; Howard Hughes Medical Institute, University of Utah School of Medicine, Salt Lake City, UT 84112, USA.
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Liu H, Zhang X, Chen W, Wang C. The regulatory functions of oxylipins in fungi: A review. J Basic Microbiol 2023; 63:1073-1084. [PMID: 37357952 DOI: 10.1002/jobm.202200721] [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: 12/29/2022] [Revised: 03/02/2023] [Accepted: 03/09/2023] [Indexed: 06/27/2023]
Abstract
Quorum sensing (QS) is a communication mechanism between microorganisms originally found in bacteria. In recent years, an important QS mechanism has been discovered in the field of fungi, namely, the lipoxygenase compound oxylipin of arachidonic acid acts as a QS molecule in life cycle control, particularly in the sexual and asexual development of fungi. However, the role of oxylipins in mediating eukaryotic communication has not been previously described. In this paper, we review the regulatory role of oxylipins and the underlying mechanisms and discuss the potential for application in major fungi. The role of oxylipin as a fungal quorum-sensing molecule is the main focus of the review. Besides, the quorum regulation of fungal morphological transformation, biofilm formation, virulence factors, secondary metabolism, infection, symbiosis, and other physiological behaviors are discussed. Moreover, future prospectives and applications are elaborated as well.
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Affiliation(s)
- Huiqian Liu
- Key Laboratory of Geriatric Nutrition and Health, Ministry of Education, Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Engineering and Technology Research Center of Food Additives, School of Food and Health, Beijing Technology and Business University, Beijing, China
| | - Xizi Zhang
- Key Laboratory of Geriatric Nutrition and Health, Ministry of Education, Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Engineering and Technology Research Center of Food Additives, School of Food and Health, Beijing Technology and Business University, Beijing, China
| | - Wei Chen
- Key Laboratory of Geriatric Nutrition and Health, Ministry of Education, Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Engineering and Technology Research Center of Food Additives, School of Food and Health, Beijing Technology and Business University, Beijing, China
| | - Chengtao Wang
- Key Laboratory of Geriatric Nutrition and Health, Ministry of Education, Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Engineering and Technology Research Center of Food Additives, School of Food and Health, Beijing Technology and Business University, Beijing, China
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The Candida glabrata Parent Strain Trap: How Phenotypic Diversity Affects Metabolic Fitness and Host Interactions. Microbiol Spectr 2023; 11:e0372422. [PMID: 36633405 PMCID: PMC9927409 DOI: 10.1128/spectrum.03724-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Reference strains improve reproducibility by standardizing observations and methodology, which has ultimately led to important insights into fungal pathogenesis. However, recent investigations have highlighted significant genotypic and phenotypic heterogeneity across isolates that influence genetic circuitry and virulence within a species. Candida glabrata is the second leading cause of candidiasis, a life-threatening infection, and undergoes extensive karyotype and phenotypic changes in response to stress. Much of the work conducted on this pathogen has focused on two sequenced strains, CBS138 (ATCC 2001) and BG2. Few studies have compared these strains in detail, but key differences include mating type and altered patterns of expression of EPA adhesins. In fact, most C. glabrata isolates and BG2 are MATa, while CBS138 is MATα. However, it is not known if other phenotypic differences between these strains play a role in our understanding of C. glabrata pathogenesis. Thus, we set out to characterize metabolic, cell wall, and host-interaction attributes for CBS138 and BG2. We found that BG2 utilized a broader range of nitrogen sources and had reduced cell wall size and carbohydrate exposure than CBS138, which we hypothesized results in differences in innate immune interactions and virulence. We observed that, although both strains were phagocytosed to a similar extent, BG2 replicated to higher numbers in macrophages and was more virulent during Galleria mellonella infection than CBS138 in a dose-dependent manner. Interestingly, deletion of SNF3, a major nutrient sensor, did not affect virulence in G. mellonella for BG2, but significantly enhanced larval killing in the CBS138 background compared to the parent strain. Understanding these fundamental differences in metabolism and host interactions will allow more robust conclusions to be drawn in future studies of C. glabrata pathogenesis. IMPORTANCE Reference strains provide essential insights into the mechanisms underlying virulence in fungal pathogens. However, recent studies in Candida albicans and other species have revealed significant genotypic and phenotypic diversity within clinical isolates that are challenging paradigms regarding key virulence factors and their regulation. Candida glabrata is the second leading cause of candidiasis, and many studies use BG2 or CBS138 for their investigations. Therefore, we aimed to characterize important virulence-related phenotypes for both strains that might alter conclusions about C. glabrata pathogenesis. Our study provides context for metabolic and cell wall changes and how these may influence host interaction phenotypes. Understanding these differences is necessary to support robust conclusions about how virulence factors may function in these and other very different strain backgrounds.
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Cao C, Wang K, Wang Y, Liu TB, Rivera A, Xue C. Ubiquitin proteolysis of a CDK-related kinase regulates titan cell formation and virulence in the fungal pathogen Cryptococcus neoformans. Nat Commun 2022; 13:6397. [PMID: 36302775 PMCID: PMC9613880 DOI: 10.1038/s41467-022-34151-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 10/17/2022] [Indexed: 12/25/2022] Open
Abstract
Fungal pathogens often undergo morphological switches, including cell size changes, to adapt to the host environment and cause disease. The pathogenic yeast Cryptococcus neoformans forms so-called 'titan cells' during infection. Titan cells are large, polyploid, display alterations in cell wall and capsule, and are more resistant to phagocytosis and various types of stress. Titan cell formation is regulated by the cAMP/PKA signal pathway, which is stimulated by the protein Gpa1. Here, we show that Gpa1 is activated through phosphorylation by a CDK-related kinase (Crk1), which is targeted for degradation by an E3 ubiquitin ligase (Fbp1). Strains overexpressing CRK1 or an allele lacking a PEST domain exhibit increased production of titan cells similarly to the fbp1∆ mutant. Conversely, CRK1 deletion results in reduced titan cell production, indicating that Crk1 stimulates titan cell formation. Crk1 phosphorylates Gpa1, which then localizes to the plasma membrane and activates the cAMP/PKA signal pathway to induce cell enlargement. Furthermore, titan cell-overproducing strains trigger increased Th1 and Th17 cytokine production in CD4+ T cells and show attenuated virulence in a mouse model of systemic cryptococcosis. Overall, our study provides insights into the regulation of titan cell formation and fungal virulence.
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Affiliation(s)
- Chengjun Cao
- Public Health Research Institute, New Jersey Medical School, Rutgers University, Newark, NJ, 07103, USA
| | - Keyi Wang
- Center for Immunity and Inflammation, New Jersey Medical School, Rutgers University, Newark, NJ, 07103, USA
| | - Yina Wang
- Public Health Research Institute, New Jersey Medical School, Rutgers University, Newark, NJ, 07103, USA
| | - Tong-Bao Liu
- Public Health Research Institute, New Jersey Medical School, Rutgers University, Newark, NJ, 07103, USA
- Medical Research Institute, Southwest University, Chongqing, 400715, China
| | - Amariliz Rivera
- Center for Immunity and Inflammation, New Jersey Medical School, Rutgers University, Newark, NJ, 07103, USA
| | - Chaoyang Xue
- Public Health Research Institute, New Jersey Medical School, Rutgers University, Newark, NJ, 07103, USA.
- Department of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, New Jersey Medical School, Rutgers University, Newark, NJ, 07103, USA.
- Rutgers Center for Lipid Research, Rutgers University, New Brunswick, NJ, 08901, USA.
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Schmoll M, Hinterdobler W. Tools for adapting to a complex habitat: G-protein coupled receptors in Trichoderma. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2022; 193:65-97. [PMID: 36357080 DOI: 10.1016/bs.pmbts.2022.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Sensing the environment and interpretation of the received signals are crucial competences of living organisms in order to properly adapt to their habitat, succeed in competition and to reproduce. G-protein coupled receptors (GPCRs) are members of a large family of sensors for extracellular signals and represent the starting point of complex signaling cascades regulating a plethora of intracellular physiological processes and output pathways in fungi. In Trichoderma spp. current research involves a wide range of topics from enzyme production, light response and secondary metabolism to sexual and asexual development as well as biocontrol, all of which require delicate balancing of resources in response to the environmental challenges or biotechnological needs at hand, which are crucially impacted by the surroundings of the fungi and their intercellular signaling cascades triggering a precisely tailored response. In this review we summarize recent findings on sensing by GPCRs in Trichoderma, including the function of pheromone receptors, glucose sensing by CSG1 and CSG2, regulation of secondary metabolism by GPR8 and impacts on mycoparasitism by GPR1. Additionally, we provide an overview on structural determinants, posttranslational modifications and interactions for regulation, activation and signal termination of GPCRs in order to inspire future in depth analyses of their function and to understand previous regulatory outcomes of natural and biotechnological processes modulated or enabled by GPCRs.
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Affiliation(s)
- Monika Schmoll
- Department of Microbiology and Ecosystem Science, Division of Terrestrial Ecosystem Research, University of Vienna, Vienna, Austria.
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Yeast-Mycelial Dimorphism in Pichia pastoris SMD1168 Is Triggered by Nutritional and Environmental Factors. Curr Microbiol 2022; 79:190. [PMID: 35556178 DOI: 10.1007/s00284-022-02884-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Accepted: 04/20/2022] [Indexed: 11/03/2022]
Abstract
This study reports, for the first time, morphological transition from yeast-like to filamentous form, normally associated with pathogenicity/increased protein secretion, in Pichia pastoris SMD1168 strain. The response was recorded in response to nutritional and environmental cues. The factors affecting this switch were extracellular pH (under nitrogen starvation conditions), carbon and nitrogen source under nitrogen- and carbon-limiting conditions respectively. Under nitrogen-limiting conditions, addition of fructose and sucrose in the culture medium induced filamentous morphology in a segregated form whereas addition of galactose led to a mixture of yeast and the filamentous form of the cells. Under carbon-limiting conditions, isoleucine and proline forced a filamentous form whereas glycine, valine, alanine and phenylalanine promoted yeast-like morphology. Similar dimorphic shift was also displayed by a recombinant methanol slow utilizing (Muts) strain (SMD-GCSF Muts) producing human granulocyte colony-stimulating factor in response to change in the initial inoculum level. Analysis of the extracellular metabolome by GC-MS indicated that several amino acids (leucine, proline, tyrosine), carboxylic acids (phenylacetic-, propanoic acid), alcohols and butylamine were present at different levels in the culture broth of the two morphological forms. High accumulation of proline and butylamine was seen in the extracellular culture filtrate of the filamentous form of the yeast. Presence of quorum-sensing molecules (phenylethyl alcohol, dodecanol) suggested complex network of pathways involved in this morphological transition.
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Li L, Zhu XM, Zhang YR, Cai YY, Wang JY, Liu MY, Wang JY, Bao JD, Lin FC. Research on the Molecular Interaction Mechanism between Plants and Pathogenic Fungi. Int J Mol Sci 2022; 23:ijms23094658. [PMID: 35563048 PMCID: PMC9104627 DOI: 10.3390/ijms23094658] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 04/07/2022] [Accepted: 04/21/2022] [Indexed: 02/01/2023] Open
Abstract
Plant diseases caused by fungi are one of the major threats to global food security and understanding the interactions between fungi and plants is of great significance for plant disease control. The interaction between pathogenic fungi and plants is a complex process. From the perspective of pathogenic fungi, pathogenic fungi are involved in the regulation of pathogenicity by surface signal recognition proteins, MAPK signaling pathways, transcription factors, and pathogenic factors in the process of infecting plants. From the perspective of plant immunity, the signal pathway of immune response, the signal transduction pathway that induces plant immunity, and the function of plant cytoskeleton are the keys to studying plant resistance. In this review, we summarize the current research progress of fungi–plant interactions from multiple aspects and discuss the prospects and challenges of phytopathogenic fungi and their host interactions.
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Affiliation(s)
- Lin Li
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-Products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China; (L.L.); (X.-M.Z.); (J.-Y.W.); (J.-D.B.)
| | - Xue-Ming Zhu
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-Products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China; (L.L.); (X.-M.Z.); (J.-Y.W.); (J.-D.B.)
| | - Yun-Ran Zhang
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-Products, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; (Y.-R.Z.); (Y.-Y.C.); (J.-Y.W.); (M.-Y.L.)
| | - Ying-Ying Cai
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-Products, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; (Y.-R.Z.); (Y.-Y.C.); (J.-Y.W.); (M.-Y.L.)
| | - Jing-Yi Wang
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-Products, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; (Y.-R.Z.); (Y.-Y.C.); (J.-Y.W.); (M.-Y.L.)
| | - Meng-Yu Liu
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-Products, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; (Y.-R.Z.); (Y.-Y.C.); (J.-Y.W.); (M.-Y.L.)
| | - Jiao-Yu Wang
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-Products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China; (L.L.); (X.-M.Z.); (J.-Y.W.); (J.-D.B.)
| | - Jian-Dong Bao
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-Products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China; (L.L.); (X.-M.Z.); (J.-Y.W.); (J.-D.B.)
| | - Fu-Cheng Lin
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-Products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China; (L.L.); (X.-M.Z.); (J.-Y.W.); (J.-D.B.)
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-Products, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; (Y.-R.Z.); (Y.-Y.C.); (J.-Y.W.); (M.-Y.L.)
- Correspondence: ; Tel.: +86-571-88404007
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Inositol Metabolism Regulates Capsule Structure and Virulence in the Human Pathogen Cryptococcus neoformans. mBio 2021; 12:e0279021. [PMID: 34724824 PMCID: PMC8561382 DOI: 10.1128/mbio.02790-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The environmental yeast Cryptococcus neoformans is the most common cause of deadly fungal meningitis in primarily immunocompromised populations. A number of factors contribute to cryptococcal pathogenesis. Among them, inositol utilization has been shown to promote C. neoformans development in nature and invasion of central nervous system during dissemination. The mechanisms of the inositol regulation of fungal virulence remain incompletely understood. In this study, we analyzed inositol-induced capsule growth and the contribution of a unique inositol catabolic pathway in fungal development and virulence. We found that genes involved in the inositol catabolic pathway are highly induced by inositol, and they are also highly expressed in the cerebrospinal fluid of patients with meningoencephalitis. This pathway in C. neoformans contains three genes encoding myo-inositol oxygenases that convert myo-inositol into d-glucuronic acid, a substrate of the pentose phosphate cycle and a component of the polysaccharide capsule. Our mutagenesis analysis demonstrates that inositol catabolism is required for C. neoformans virulence and deletion mutants of myo-inositol oxygenases result in altered capsule growth as well as the polysaccharide structure, including O-acetylation. Our study indicates that the ability to utilize the abundant inositol in the brain may contribute to fungal pathogenesis in this neurotropic fungal pathogen. IMPORTANCE The human pathogen Cryptococcus neoformans is the leading cause of fungal meningitis in primarily immunocompromised populations. Understanding how this environmental organism adapts to the human host to cause deadly infection will guide our development of novel disease control strategies. Our recent studies revealed that inositol utilization by the fungus promotes C. neoformans development in nature and invasion of the central nervous system during infection. The mechanisms of the inositol regulation in fungal virulence remain incompletely understood. In this study, we found that C. neoformans has three genes encoding myo-inositol oxygenase, a key enzyme in the inositol catabolic pathway. Expression of these genes is highly induced by inositol, and they are highly expressed in the cerebrospinal fluid of patients with meningoencephalitis. Our mutagenesis analysis indeed demonstrates that inositol catabolism is required for C. neoformans virulence by altering the growth and structure of polysaccharide capsule, a major virulence factor. Considering the abundance of free inositol and inositol-related metabolites in the brain, our study reveals an important mechanism of host inositol-mediated fungal pathogenesis for this neurotropic fungal pathogen.
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The Cyclin Cln1 Controls Polyploid Titan Cell Formation following a Stress-Induced G 2 Arrest in Cryptococcus. mBio 2021; 12:e0250921. [PMID: 34634930 PMCID: PMC8510536 DOI: 10.1128/mbio.02509-21] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The pathogenic yeast Cryptococcus neoformans produces polyploid titan cells in response to the host lung environment that are critical for host adaptation and subsequent disease. We analyzed the in vivo and in vitro cell cycles to identify key aspects of the C. neoformans cell cycle that are important for the formation of titan cells. We identified unbudded 2C cells, referred to as a G2 arrest, produced both in vivo and in vitro in response to various stresses. Deletion of the nonessential cyclin Cln1 resulted in overproduction of titan cells in vivo and transient morphology defects upon release from stationary phase in vitro. Using a copper-repressible promoter PCTR4-CLN1 strain and a two-step in vitro titan cell formation assay, our in vitro studies revealed Cln1 functions after the G2 arrest. These studies highlight unique cell cycle alterations in C. neoformans that ultimately promote genomic diversity and virulence in this important fungal pathogen.
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Johns LE, Goldman GH, Ries LN, Brown NA. Nutrient sensing and acquisition in fungi: mechanisms promoting pathogenesis in plant and human hosts. FUNGAL BIOL REV 2021. [DOI: 10.1016/j.fbr.2021.01.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Chen Y, Fan X, Zhao X, Shen Y, Xu X, Wei L, Wang W, Wei D. cAMP activates calcium signalling via phospholipase C to regulate cellulase production in the filamentous fungus Trichoderma reesei. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:62. [PMID: 33685506 PMCID: PMC7941909 DOI: 10.1186/s13068-021-01914-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 02/21/2021] [Indexed: 05/15/2023]
Abstract
BACKGROUND The filamentous fungus Trichoderma reesei is one of the best producers of cellulase and has been widely studied for the production of cellulosic ethanol and bio-based products. We previously reported that Mn2+ and N,N-dimethylformamide (DMF) can stimulate cellulase overexpression via Ca2+ bursts and calcium signalling in T. reesei under cellulase-inducing conditions. To further understand the regulatory networks involved in cellulase overexpression in T. reesei, we characterised the Mn2+/DMF-induced calcium signalling pathway involved in the stimulation of cellulase overexpression. RESULTS We found that Mn2+/DMF stimulation significantly increased the intracellular levels of cAMP in an adenylate cyclase (ACY1)-dependent manner. Deletion of acy1 confirmed that cAMP is crucial for the Mn2+/DMF-stimulated cellulase overexpression in T. reesei. We further revealed that cAMP elevation induces a cytosolic Ca2+ burst, thereby initiating the Ca2+ signal transduction pathway in T. reesei, and that cAMP signalling causes the Ca2+ signalling pathway to regulate cellulase production in T. reesei. Furthermore, using a phospholipase C encoding gene plc-e deletion strain, we showed that the plc-e gene is vital for cellulase overexpression in response to stimulation by both Mn2+ and DMF, and that cAMP induces a Ca2+ burst through PLC-E. CONCLUSIONS The findings of this study reveal the presence of a signal transduction pathway in which Mn2+/DMF stimulation produces cAMP. Increase in the levels of cAMP activates the calcium signalling pathway via phospholipase C to regulate cellulase overexpression under cellulase-inducing conditions. These findings provide insights into the molecular mechanism of the cAMP-PLC-calcium signalling pathway underlying cellulase expression in T. reesei and highlight the potential applications of signal transduction in the regulation of gene expression in fungi.
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Affiliation(s)
- Yumeng Chen
- State Key Lab of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, 130 Meilong Road , P.O.B. 311, Shanghai, 200237, China
| | - Xingjia Fan
- State Key Lab of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, 130 Meilong Road , P.O.B. 311, Shanghai, 200237, China
| | - Xinqing Zhao
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Yaling Shen
- State Key Lab of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, 130 Meilong Road , P.O.B. 311, Shanghai, 200237, China
| | - Xiangyang Xu
- Zaozhuang Jie Nuo Enzyme Co. Ltd., Shandong, China
| | - Liujing Wei
- State Key Lab of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, 130 Meilong Road , P.O.B. 311, Shanghai, 200237, China
| | - Wei Wang
- State Key Lab of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, 130 Meilong Road , P.O.B. 311, Shanghai, 200237, China.
| | - Dongzhi Wei
- State Key Lab of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, 130 Meilong Road , P.O.B. 311, Shanghai, 200237, China
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15
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Gao J, Xu X, Huang K, Liang Z. Fungal G-Protein-Coupled Receptors: A Promising Mediator of the Impact of Extracellular Signals on Biosynthesis of Ochratoxin A. Front Microbiol 2021; 12:631392. [PMID: 33643259 PMCID: PMC7907439 DOI: 10.3389/fmicb.2021.631392] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 01/21/2021] [Indexed: 01/17/2023] Open
Abstract
G-protein-coupled receptors (GPCRs) are transmembrane receptors involved in transducing signals from the external environment inside the cell, which enables fungi to coordinate cell transport, metabolism, and growth to promote their survival, reproduction, and virulence. There are 14 classes of GPCRs in fungi involved in sensing various ligands. In this paper, the synthesis of mycotoxins that are GPCR-mediated is discussed with respect to ligands, environmental stimuli, and intra-/interspecific communication. Despite their apparent importance in fungal biology, very little is known about the role of ochratoxin A (OTA) biosynthesis by Aspergillus ochraceus and the ligands that are involved. Fortunately, increasing evidence shows that the GPCR that involves the AF/ST (sterigmatocystin) pathway in fungi belongs to the same genus. Therefore, we speculate that GPCRs play an important role in a variety of environmental signals and downstream pathways in OTA biosynthesis. The verification of this inference will result in a more controllable GPCR target for control of fungal contamination in the future.
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Affiliation(s)
- Jing Gao
- Beijing Laboratory for Food Quality and Safety, Beijing, China
| | - Xinge Xu
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
| | - Kunlun Huang
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
| | - Zhihong Liang
- Beijing Laboratory for Food Quality and Safety, Beijing, China.,College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
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16
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Spencer GWK, Chua SMH, Erpf PE, Wizrah MSI, Dyba TG, Condon ND, Fraser JA. Broadening the spectrum of fluorescent protein tools for use in the encapsulated human fungal pathogen Cryptococcus neoformans. Fungal Genet Biol 2020; 138:103365. [PMID: 32145317 DOI: 10.1016/j.fgb.2020.103365] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Revised: 02/25/2020] [Accepted: 02/26/2020] [Indexed: 12/31/2022]
Abstract
Green fluorescent protein (GFP) and its counterparts are modern molecular biology research tools indispensable in many experimental systems. Within fungi, researchers studying Saccharomyces cerevisiae and other model ascomycetes have access to a wide variety of fluorescent proteins. Unfortunately, many of these tools have not crossed the phylum divide into the Basidiomycota, where only GFP S65T, Venus, Ds-Red, and mCherry are currently available. To address this, we searched the literature for potential candidates to be expressed in the human fungal pathogen Cryptococcus neoformans and identified a suite of eight more modern fluorescent proteins that span the visible spectrum. A single copy of each fluorophore was heterologously expressed in Safe Haven 1 and their fluorescence intensities compared in this encapsulated yeast. mTurquoise2, mTFP1, Clover, mNeonGreen, mRuby3, and Citrine were highly visible under the microscope, whereas Superfolder GFP and mMaroon1 were not. Expressed fluorophores did not impact growth or virulence as demonstrated by an in vitro spotting assay and murine inhalation model, respectively.
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Affiliation(s)
- Garrick W K Spencer
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia; School of Chemistry & Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
| | - Sheena M H Chua
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia; School of Chemistry & Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
| | - Paige E Erpf
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia; School of Chemistry & Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
| | - Maha S I Wizrah
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia; School of Chemistry & Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
| | - Taylor G Dyba
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia; School of Chemistry & Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
| | - Nicholas D Condon
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072 Australia
| | - James A Fraser
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia; School of Chemistry & Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia.
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Matsumoto Y, Azami S, Shiga H, Nagamachi T, Moriyama H, Yamashita Y, Yoshikawa A, Sugita T. Induction of signal transduction pathways related to the pathogenicity of Cryptococcus neoformans in the host environment. Drug Discov Ther 2020; 13:177-182. [PMID: 31534068 DOI: 10.5582/ddt.2019.01047] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Cryptococcus neoformans, a human pathogenic fungus, infects immunocompromised humans and causes serious diseases such as cerebral meningitis. C. neoformans controls the expression of virulence factors in response to the host environment via various signal transduction pathways. Understanding the molecular mechanisms involved in C. neoformans infection will contribute to the development of methods to prevent and treat C. neoformans-related diseases. C. neoformans produces virulence factors, such as a polysaccharide capsule and melanin, to escape host immunity. Several proteins of C. neoformans are reported to regulate production of the virulence factors. In this review, on the basis of studies using gene-deficient mutants of C. neoformans and animal infection models, we outline the signal transduction pathways involved in the regulation of virulence factors.
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Affiliation(s)
| | - Saki Azami
- Department of Microbiology, Meiji Pharmaceutical University
| | - Haruka Shiga
- Department of Microbiology, Meiji Pharmaceutical University
| | - Tae Nagamachi
- Department of Microbiology, Meiji Pharmaceutical University
| | | | - Yuki Yamashita
- Department of Microbiology, Meiji Pharmaceutical University
| | | | - Takashi Sugita
- Department of Microbiology, Meiji Pharmaceutical University
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18
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Abstract
G-protein-coupled receptors (GPCRs) are the largest family of transmembrane receptors in fungi. These receptors have an important role in the transduction of extracellular signals into intracellular sites in response to diverse stimuli. They enable fungi to coordinate cell function and metabolism, thereby promoting their survival and propagation, and sense certain fundamentally conserved elements, such as nutrients, pheromones, and stress, for adaptation to their niches, environmental stresses, and host environment, causing disease and pathogen virulence. This chapter highlights the role of GPCRs in fungi in coordinating cell function and metabolism. Fungal cells sense the molecular interactions between extracellular signals. Their respective sensory systems are described here in detail.
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Affiliation(s)
- Abd El-Latif Hesham
- Department of Genetics Faculty of Agriculture, Beni-Suef University, Beni-Suef, Egypt
| | | | | | | | - Vijai Kumar Gupta
- AgroBioSciences and Chemical & Biochemical Sciences Department, University Mohammed VI Polytechnic (UM6P), Benguerir, Morocco
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19
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Maybruck BT, Lam WC, Specht CA, Ilagan MXG, Donlin MJ, Lodge JK. The Aminoalkylindole BML-190 Negatively Regulates Chitosan Synthesis via the Cyclic AMP/Protein Kinase A1 Pathway in Cryptococcus neoformans. mBio 2019; 10:e02264-19. [PMID: 31848271 PMCID: PMC6918072 DOI: 10.1128/mbio.02264-19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 10/31/2019] [Indexed: 02/06/2023] Open
Abstract
Cryptococcus neoformans can cause fatal meningoencephalitis in patients with AIDS or other immunocompromising conditions. Current antifungals are suboptimal to treat this disease; therefore, novel targets and new therapies are needed. Previously, we have shown that chitosan is a critical component of the cryptococcal cell wall and is required for survival in the mammalian host and that chitosan deficiency results in rapid clearance from the mammalian host. We had also identified several specific proteins that were required for chitosan biosynthesis, and we hypothesize that screening for compounds that inhibit chitosan biosynthesis would identify additional genes/proteins that influence chitosan biosynthesis. To identify these compounds, we developed a robust and novel cell-based flow cytometry screening method to identify small-molecule inhibitors of chitosan production. We screened the ICCB Known Bioactives library and identified 8 compounds that reduced chitosan in C. neoformans We used flow cytometry-based counterscreens and confirmatory screens, followed by a biochemical secondary screen to refine our primary screening hits to 2 confirmed hits. One of the confirmed hits that reduced chitosan content was the aminoalkylindole BML-190, a known inverse agonist of mammalian cannabinoid receptors. We demonstrated that BML-190 likely targets the C. neoformans G-protein-coupled receptor Gpr4 and, via the cyclic AMP (cAMP)/protein kinase A (PKA) signaling pathway, contributes to an intracellular accumulation of cAMP that results in decreased chitosan. Our discovery suggests that this approach could be used to identify additional compounds and pathways that reduce chitosan biosynthesis and could lead to potential novel therapeutics against C. neoformansIMPORTANCECryptococcus neoformans is a fungal pathogen that kills ∼200,000 people every year. The cell wall is an essential organelle that protects fungi from the environment. Chitosan, the deacetylated form of chitin, has been shown to be an essential component of the cryptococcal cell wall during infection of a mammalian host. In this study, we screened a set of 480 compounds, which are known to have defined biological activities, for activity that reduced chitosan production in C. neoformans Two of these compounds were confirmed using an alternative method of measuring chitosan, and one of these was demonstrated to impact the cAMP signal transduction pathway. This work demonstrates that the cAMP pathway regulates chitosan biosynthesis in C. neoformans and validates that this screening approach could be used to find potential antifungal agents.
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Affiliation(s)
- Brian T Maybruck
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Woei C Lam
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Charles A Specht
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Ma Xenia G Ilagan
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Maureen J Donlin
- Department of Biochemistry and Molecular Biology, Saint Louis University, St. Louis, Missouri, USA
| | - Jennifer K Lodge
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
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20
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A Mechanosensitive Channel Governs Lipid Flippase-Mediated Echinocandin Resistance in Cryptococcus neoformans. mBio 2019; 10:mBio.01952-19. [PMID: 31822582 PMCID: PMC6904872 DOI: 10.1128/mbio.01952-19] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Echinocandins show fungicidal activity against common invasive mycoses but are ineffective against cryptococcosis. The underlying mechanism for echinocandin resistance in Cryptococcus neoformans remains poorly understood but has been shown to involve Cdc50, the regulatory subunit of lipid flippase. In a forward genetic screen for cdc50Δ suppressor mutations that are caspofungin resistant, we identified Crm1 (caspofungin resistant mutation 1), a homolog of mechanosensitive channel proteins, and showed that crm1Δ restored caspofungin resistance in cdc50Δ cells. Caspofungin-treated cdc50Δ cells exhibited abnormally high intracellular calcium levels ([Ca2+]c) and heightened activation of the calcineurin pathway. Deletion of CRM1 in the cdc50Δ background normalized the abnormally high [Ca2+]c. Cdc50 interacts with Crm1 to maintain cellular calcium homeostasis. Analysis of chitin/chitosan content showed that deleting CRM1 reversed the decreased chitosan production of cdc50Δ cells. Together, these results demonstrate that Cdc50 and Crm1 regulation of the calcineurin pathway and cytoplasmic calcium homeostasis may underlie caspofungin resistance in C. neoformans IMPORTANCE Cryptococcus neoformans is the leading cause of fungal meningitis, accounting for ∼15% of HIV/AIDS-related deaths, but treatment options for cryptococcosis are limited. Echinocandins are the newest fungicidal drug class introduced but are ineffective in treating cryptococcosis. Our previous study identified the lipid flippase subunit Cdc50 as a contributor to echinocandin resistance in C. neoformans Here, we further elucidated the mechanism of Cdc50-mediated caspofungin drug resistance. We discovered that Cdc50 interacts with the mechanosensitive calcium channel protein Crm1 to regulate calcium homeostasis and caspofungin resistance via calcium/calcineurin signaling. These results provide novel insights into echinocandin resistance in this pathogen, which may lead to new treatment options, as well as inform echinocandin resistance mechanisms in other fungal organisms and, hence, advance our understanding of modes of antifungal drug susceptibility and resistance.
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21
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Yu M, Cui R, Huang Y, Luo Y, Qin S, Zhong M. Increased proton-sensing receptor GPR4 signalling promotes colorectal cancer progression by activating the hippo pathway. EBioMedicine 2019; 48:264-276. [PMID: 31530502 PMCID: PMC6838423 DOI: 10.1016/j.ebiom.2019.09.016] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 09/01/2019] [Accepted: 09/09/2019] [Indexed: 12/24/2022] Open
Abstract
Background Colorectal cancer (CRC) is one of the high incidences tumours and is ranked second in cancer-related mortality. Even though great progress has been made, there are no effective therapeutic strategies for late stage and metastatic CRC patients. Acidity is one characteristic of the tumour microenvironment. However, how cancer cells respond to this acidic environment surrounding them remains largely unknown, especially in colorectal cancer. Methods Proton sensor receptor expression was analysed in GEO and TCGA datasets. The expression of GPR4 in CRC specimens was confirmed by western blotting and immunohistochemistry (IHC). The role of GPR4 in CRC progression was analysed both in vitro and in vivo. Pharmacological intervention, immunofluorescence and gene set enrichment analyses were performed to reveal the underlying molecular mechanisms of GPR4. Findings We found that GPR4 was upregulated in CRC samples. In addition, its high expression correlated with late stage tumours and poor overall survival in patients. Furthermore, loss-of-function assays proved that GPR4 promoted CRC carcinogenesis and metastatic ability. Mechanistically, GPR4 was activated by extracellular protons in the tumour microenvironment and enhanced RhoA activation and F-actin rearrangement, leading to LATS activity inhibition, YAP1 nuclear translocation and oncogene transcription. Interpretation The expression of GPR4 is upregulated in colorectal cancer and is associated with shorter overall survival time in CRC patients. These findings reveal the novel roles of GPR4 in CRC progression and suggest GPR4 might be a new therapeutic target for CRC treatment.
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Affiliation(s)
- Minhao Yu
- Department of Gastrointestinal Surgery, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China
| | - Ran Cui
- Department of Hepatopancreatobiliary Surgery, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, China
| | - Yizhou Huang
- Department of Gastrointestinal Surgery, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China
| | - Yang Luo
- Department of Gastrointestinal Surgery, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China
| | - Shaolan Qin
- Department of Gastrointestinal Surgery, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China
| | - Ming Zhong
- Department of Gastrointestinal Surgery, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China.
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22
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Role of Amino Acid Metabolism in the Virulence of Human Pathogenic Fungi. CURRENT CLINICAL MICROBIOLOGY REPORTS 2019. [DOI: 10.1007/s40588-019-00124-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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23
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Caza M, Kronstad JW. The cAMP/Protein Kinase a Pathway Regulates Virulence and Adaptation to Host Conditions in Cryptococcus neoformans. Front Cell Infect Microbiol 2019; 9:212. [PMID: 31275865 PMCID: PMC6592070 DOI: 10.3389/fcimb.2019.00212] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 05/31/2019] [Indexed: 12/28/2022] Open
Abstract
Nutrient sensing is critical for adaptation of fungi to environmental and host conditions. The conserved cAMP/PKA signaling pathway contributes to adaptation by sensing the availability of key nutrients such as glucose and directing changes in gene expression and metabolism. Interestingly, the cAMP/PKA pathway in fungal pathogens also influences the expression of virulence determinants in response to nutritional and host signals. For instance, protein kinase A (PKA) in the human pathogen Cryptococcus neoformans plays a central role in orchestrating phenotypic changes, such as capsule elaboration and melanin production, that directly impact disease development. In this review, we focus first on insights into the role of the cAMP/PKA pathway in nutrient sensing for the model yeast Saccharomyces cerevisiae to provide a foundation for understanding the pathway in C. neoformans. We then discuss key features of cAMP/PKA signaling in C. neoformans including new insights emerging from the analysis of transcriptional and proteomic changes in strains with altered PKA activity and expression. Finally, we highlight recent studies that connect the cAMP/PKA pathway to cell surface remodeling and the formation of titan cells.
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Affiliation(s)
- Mélissa Caza
- Michael Smith Laboratories, Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada
| | - James W Kronstad
- Michael Smith Laboratories, Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada
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24
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Sensing and transduction of nutritional and chemical signals in filamentous fungi: Impact on cell development and secondary metabolites biosynthesis. Biotechnol Adv 2019; 37:107392. [PMID: 31034961 DOI: 10.1016/j.biotechadv.2019.04.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 04/22/2019] [Accepted: 04/25/2019] [Indexed: 11/23/2022]
Abstract
Filamentous fungi respond to hundreds of nutritional, chemical and environmental signals that affect expression of primary metabolism and biosynthesis of secondary metabolites. These signals are sensed at the membrane level by G protein coupled receptors (GPCRs). GPCRs contain usually seven transmembrane domains, an external amino terminal fragment that interacts with the ligand, and an internal carboxy terminal end interacting with the intracellular G protein. There is a great variety of GPCRs in filamentous fungi involved in sensing of sugars, amino acids, cellulose, cell-wall components, sex pheromones, oxylipins, calcium ions and other ligands. Mechanisms of signal transduction at the membrane level by GPCRs are discussed, including the internalization and compartmentalisation of these sensor proteins. We have identified and analysed the GPCRs in the genome of Penicillium chrysogenum and compared them with GPCRs of several other filamentous fungi. We have found 66 GPCRs classified into 14 classes, depending on the ligand recognized by these proteins, including most previously proposed classes of GPCRs. We have found 66 putative GPCRs, representatives of twelve of the fourteen previously proposed classes of GPCRs, depending on the ligand recognized by these proteins. A staggering fortytwo putative members of the new GPCR class XIV, the so-called Pth11 sensors of cellulosic material as reported for Neurospora crassa and some other fungi, were identified. Several GPCRs sensing sex pheromones, known in yeast and in several fungi, were also identified in P. chrysogenum, confirming the recent unravelling of the hidden sexual capacity of this species. Other sensing mechanisms do not involve GPCRs, including the two-component systems (HKRR), the HOG signalling system and the PalH mediated pH transduction sensor. GPCR sensor proteins transmit their signals by interacting with intracellular heterotrimeric G proteins, that are well known in several fungi, including P. chrysogenum. These G proteins are inactive in the GDP containing heterotrimeric state, and become active by nucleotide exchange, allowing the separation of the heterotrimeric protein in active Gα and Gβγ dimer subunits. The conversion of GTP in GDP is mediated by the endogenous GTPase activity of the G proteins. Downstream of the ligand interaction, the activated Gα protein and also the Gβ/Gγ dimer, transduce the signals through at least three different cascades: adenylate cyclase/cAMP, MAPK kinase, and phospholipase C mediated pathways.
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25
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Torán JL, López JA, Gomes-Alves P, Aguilar S, Torroja C, Trevisan-Herraz M, Moscoso I, Sebastião MJ, Serra M, Brito C, Cruz FM, Sepúlveda JC, Abad JL, Galán-Arriola C, Ibanez B, Martínez F, Fernández ME, Fernández-Aviles F, Palacios I, R-Borlado L, Vázquez J, Alves PM, Bernad A. Definition of a cell surface signature for human cardiac progenitor cells after comprehensive comparative transcriptomic and proteomic characterization. Sci Rep 2019; 9:4647. [PMID: 30874584 PMCID: PMC6420620 DOI: 10.1038/s41598-019-39571-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 01/22/2019] [Indexed: 12/24/2022] Open
Abstract
Adult cardiac progenitor/stem cells (CPC/CSC) are multipotent resident populations involved in cardiac homeostasis and heart repair. Assisted by complementary RNAseq analysis, we defined the fraction of the CPC proteome associable with specific functions by comparison with human bone marrow mesenchymal stem cells (MSC), the reference population for cell therapy, and human dermal fibroblasts (HDF), as a distant reference. Label-free proteomic analysis identified 526 proteins expressed differentially in CPC. iTRAQ analysis confirmed differential expression of a substantial proportion of those proteins in CPC relative to MSC, and systems biology analysis defined a clear overrepresentation of several categories related to enhanced angiogenic potential. The CPC plasma membrane compartment comprised 1,595 proteins, including a minimal signature of 167 proteins preferentially or exclusively expressed by CPC. CDH5 (VE-cadherin), OX2G (OX-2 membrane glycoprotein; CD200), GPR4 (G protein-coupled receptor 4), CACNG7 (calcium voltage-gated channel auxiliary subunit gamma 7) and F11R (F11 receptor; junctional adhesion molecule A; JAM-A; CD321) were selected for validation. Their differential expression was confirmed both in expanded CPC batches and in early stages of isolation, particularly when compared against cardiac fibroblasts. Among them, GPR4 demonstrated the highest discrimination capacity between all cell lineages analyzed.
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Affiliation(s)
- José Luis Torán
- Department of Immunology and Oncology, Centro Nacional de Biotecnología (CNB-CSIC), Campus Universidad Autónoma de Madrid, 28049, Madrid, Spain.,Cardiovascular Development and Repair Department, Spanish National Cardiovascular Research Center (CNIC), Melchor Fernández Almagro 3, 28029, Madrid, Spain
| | - Juan Antonio López
- Laboratory of Cardiovascular Proteomics, Spanish National Cardiovascular Research Center (CNIC), Melchor Fernández Almagro 3, 28029, Madrid, Spain
| | - Patricia Gomes-Alves
- iBET, Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901, Oeiras, Portugal.,Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av. da República, 2780-157, Oeiras, Portugal
| | - Susana Aguilar
- Department of Immunology and Oncology, Centro Nacional de Biotecnología (CNB-CSIC), Campus Universidad Autónoma de Madrid, 28049, Madrid, Spain.,Cardiovascular Development and Repair Department, Spanish National Cardiovascular Research Center (CNIC), Melchor Fernández Almagro 3, 28029, Madrid, Spain
| | - Carlos Torroja
- Bioinformatics Unit, Spanish National Cardiovascular Research Center (CNIC), Melchor Fernández Almagro 3, 28029, Madrid, Spain
| | - Marco Trevisan-Herraz
- Laboratory of Cardiovascular Proteomics, Spanish National Cardiovascular Research Center (CNIC), Melchor Fernández Almagro 3, 28029, Madrid, Spain
| | - Isabel Moscoso
- Cardiovascular Development and Repair Department, Spanish National Cardiovascular Research Center (CNIC), Melchor Fernández Almagro 3, 28029, Madrid, Spain.,CIMUS, Avda Barcelona s/n, Santiago de Compostela, 15782A, Coruña, Spain
| | - Maria João Sebastião
- iBET, Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901, Oeiras, Portugal.,Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av. da República, 2780-157, Oeiras, Portugal
| | - Margarida Serra
- iBET, Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901, Oeiras, Portugal.,Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av. da República, 2780-157, Oeiras, Portugal
| | - Catarina Brito
- iBET, Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901, Oeiras, Portugal.,Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av. da República, 2780-157, Oeiras, Portugal
| | - Francisco Miguel Cruz
- Cardiovascular Development and Repair Department, Spanish National Cardiovascular Research Center (CNIC), Melchor Fernández Almagro 3, 28029, Madrid, Spain
| | - Juan Carlos Sepúlveda
- Department of Immunology and Oncology, Centro Nacional de Biotecnología (CNB-CSIC), Campus Universidad Autónoma de Madrid, 28049, Madrid, Spain.,Cardiovascular Development and Repair Department, Spanish National Cardiovascular Research Center (CNIC), Melchor Fernández Almagro 3, 28029, Madrid, Spain
| | - José Luis Abad
- Coretherapix S.L. U. Santiago Grisolia 2, 28769, Tres Cantos, Madrid, Spain
| | - Carlos Galán-Arriola
- Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
| | - Borja Ibanez
- Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
| | - Fernando Martínez
- Bioinformatics Unit, Spanish National Cardiovascular Research Center (CNIC), Melchor Fernández Almagro 3, 28029, Madrid, Spain
| | - María Eugenia Fernández
- Department of Cardiology, Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón, C/ Dr Esquerdo, 46, 28007, Madrid, Spain
| | - Francisco Fernández-Aviles
- Department of Cardiology, Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón, C/ Dr Esquerdo, 46, 28007, Madrid, Spain
| | - Itziar Palacios
- Coretherapix S.L. U. Santiago Grisolia 2, 28769, Tres Cantos, Madrid, Spain
| | - Luis R-Borlado
- Coretherapix S.L. U. Santiago Grisolia 2, 28769, Tres Cantos, Madrid, Spain
| | - Jesús Vázquez
- Laboratory of Cardiovascular Proteomics, Spanish National Cardiovascular Research Center (CNIC), Melchor Fernández Almagro 3, 28029, Madrid, Spain
| | - Paula M Alves
- iBET, Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901, Oeiras, Portugal.,Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av. da República, 2780-157, Oeiras, Portugal
| | - Antonio Bernad
- Department of Immunology and Oncology, Centro Nacional de Biotecnología (CNB-CSIC), Campus Universidad Autónoma de Madrid, 28049, Madrid, Spain. .,Cardiovascular Development and Repair Department, Spanish National Cardiovascular Research Center (CNIC), Melchor Fernández Almagro 3, 28029, Madrid, Spain.
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26
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Rutherford JC, Bahn YS, van den Berg B, Heitman J, Xue C. Nutrient and Stress Sensing in Pathogenic Yeasts. Front Microbiol 2019; 10:442. [PMID: 30930866 PMCID: PMC6423903 DOI: 10.3389/fmicb.2019.00442] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 02/20/2019] [Indexed: 12/23/2022] Open
Abstract
More than 1.5 million fungal species are estimated to live in vastly different environmental niches. Despite each unique host environment, fungal cells sense certain fundamentally conserved elements, such as nutrients, pheromones and stress, for adaptation to their niches. Sensing these extracellular signals is critical for pathogens to adapt to the hostile host environment and cause disease. Hence, dissecting the complex extracellular signal-sensing mechanisms that aid in this is pivotal and may facilitate the development of new therapeutic approaches to control fungal infections. In this review, we summarize the current knowledge on how two important pathogenic yeasts, Candida albicans and Cryptococcus neoformans, sense nutrient availability, such as carbon sources, amino acids, and ammonium, and different stress signals to regulate their morphogenesis and pathogenicity in comparison with the non-pathogenic model yeast Saccharomyces cerevisiae. The molecular interactions between extracellular signals and their respective sensory systems are described in detail. The potential implication of analyzing nutrient and stress-sensing systems in antifungal drug development is also discussed.
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Affiliation(s)
- Julian C Rutherford
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Yong-Sun Bahn
- Department of Biotechnology, Yonsei University, Seoul, South Korea
| | - Bert van den Berg
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Joseph Heitman
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, United States
| | - Chaoyang Xue
- Public Health Research Institute, Rutgers University, Newark, NJ, United States.,Department of Molecular Genetics, Biochemistry and Microbiology, Rutgers University, Newark, NJ, United States
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27
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Calvete CL, Martho KF, Felizardo G, Paes A, Nunes JM, Ferreira CO, Vallim MA, Pascon RC. Amino acid permeases in Cryptococcus neoformans are required for high temperature growth and virulence; and are regulated by Ras signaling. PLoS One 2019; 14:e0211393. [PMID: 30682168 PMCID: PMC6347259 DOI: 10.1371/journal.pone.0211393] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 01/11/2019] [Indexed: 11/22/2022] Open
Abstract
Cryptococcosis is an Invasive Fungal Infection (IFI) caused by Cryptococcus neoformans, mainly in immunocompromised patients. Therapeutic failure due to pathogen drug resistance, treatment inconstancy and few antifungal options is a problem. The study of amino acid biosynthesis and uptake represents an opportunity to explore possible development of novel antifungals. C. neoformans has 10 amino acids permeases, two of them (Aap3 and Aap7) not expressed at the conditions tested, and five were studied previously (Aap2, Aap4, Aap5, Mup1 and Mup3). Our previous results showed that Aap4 and Aap5 are major permeases with overlapping functions. The aap4Δ/aap5Δ double mutant fails to grow in amino acids as sole nitrogen source and is avirulent in animal model. Here, we deleted the remaining amino acid permeases (AAP1, AAP6, AAP8) that showed gene expression modulation by nutritional condition and created a double mutant (aap1Δ/aap2Δ). We studied the virulence attributes of these mutants and explored the regulatory mechanism behind amino acid uptake in C. neoformans. The aap1Δ/aap2Δ strain had reduced growth at 37°C in L-amino acids, reduced capsule production and was hypovirulent in the Galleria mellonella animal model. Our data, along with previous studies, (i) complement the analysis for all 10 amino acid permeases mutants, (ii) corroborate the idea that these transporters behave as global permeases, (iii) are required during heat and nutritional stress, and (iv) are important for virulence. Our study also indicates a new possible link between Ras1 signaling and amino acids uptake.
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Affiliation(s)
- Crislaine Lambiase Calvete
- Universidade de São Paulo, Biotechnology Graduate Program, São Paulo, SP, Brazil
- Universidade Federal de São Paulo, Campus Diadema, Department of Biological Sciences, Diadema, SP, Brazil
| | - Kevin Felipe Martho
- Universidade Federal de São Paulo, Campus Diadema, Department of Biological Sciences, Diadema, SP, Brazil
| | - Gabrielle Felizardo
- Universidade Federal de São Paulo, Campus Diadema, Department of Biological Sciences, Diadema, SP, Brazil
| | - Alexandre Paes
- Universidade Federal de São Paulo, Campus Diadema, Department of Biological Sciences, Diadema, SP, Brazil
| | - João Miguel Nunes
- Universidade Federal de São Paulo, Campus Diadema, Department of Biological Sciences, Diadema, SP, Brazil
| | - Camila Oliveira Ferreira
- Universidade Federal de São Paulo, Campus Diadema, Department of Biological Sciences, Diadema, SP, Brazil
| | - Marcelo A. Vallim
- Universidade Federal de São Paulo, Campus Diadema, Department of Biological Sciences, Diadema, SP, Brazil
| | - Renata C. Pascon
- Universidade Federal de São Paulo, Campus Diadema, Department of Biological Sciences, Diadema, SP, Brazil
- * E-mail:
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28
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Zhou X, Ballou ER. The Cryptococcus neoformans Titan Cell: From In Vivo Phenomenon to In Vitro Model. CURRENT CLINICAL MICROBIOLOGY REPORTS 2018. [DOI: 10.1007/s40588-018-0107-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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29
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ATG Genes Influence the Virulence of Cryptococcus neoformans through Contributions beyond Core Autophagy Functions. Infect Immun 2018; 86:IAI.00069-18. [PMID: 29986893 DOI: 10.1128/iai.00069-18] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 07/03/2018] [Indexed: 12/31/2022] Open
Abstract
The process of autophagy is conserved among all eukaryotes from yeast to humans and is mainly responsible for bulk degradation of cellular contents and nutrient recycling during starvation. Autophagy has been suggested to play a role in the pathogenesis of the opportunistic human fungal pathogen Cryptococcus neoformans, potentially through a contribution to the export of virulence factors. In this study, we showed that deletion of each of the ATG1, ATG7, ATG8, and ATG9 genes in C. neoformans leads to autophagy-related phenotypes, including impaired amino acid homeostasis under nitrogen starvation. In addition, the atgΔ mutants were hypersensitive to inhibition of the ubiquitin-proteasome system, a finding consistent with a role in amino acid homeostasis. Although each atgΔ mutant was not markedly impaired in virulence factor production in vitro, we found that all four ATG genes contribute to C. neoformans virulence in a murine inhalation model of cryptococcosis. Interestingly, these mutants displayed significant differences in their ability to promote disease development. A more detailed investigation of virulence for the atg1Δ and atg8Δ mutants revealed that both strains stimulated an exaggerated host immune response, which, in turn, contributed to disease severity. Overall, our results suggest that different ATG genes are involved in nonautophagic functions and contribute to C. neoformans virulence beyond their core functions in autophagy.
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30
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Dambuza IM, Drake T, Chapuis A, Zhou X, Correia J, Taylor-Smith L, LeGrave N, Rasmussen T, Fisher MC, Bicanic T, Harrison TS, Jaspars M, May RC, Brown GD, Yuecel R, MacCallum DM, Ballou ER. The Cryptococcus neoformans Titan cell is an inducible and regulated morphotype underlying pathogenesis. PLoS Pathog 2018; 14:e1006978. [PMID: 29775474 PMCID: PMC5959070 DOI: 10.1371/journal.ppat.1006978] [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: 09/19/2017] [Accepted: 03/16/2018] [Indexed: 02/06/2023] Open
Abstract
Fungal cells change shape in response to environmental stimuli, and these morphogenic transitions drive pathogenesis and niche adaptation. For example, dimorphic fungi switch between yeast and hyphae in response to changing temperature. The basidiomycete Cryptococcus neoformans undergoes an unusual morphogenetic transition in the host lung from haploid yeast to large, highly polyploid cells termed Titan cells. Titan cells influence fungal interaction with host cells, including through increased drug resistance, altered cell size, and altered Pathogen Associated Molecular Pattern exposure. Despite the important role these cells play in pathogenesis, understanding the environmental stimuli that drive the morphological transition, and the molecular mechanisms underlying their unique biology, has been hampered by the lack of a reproducible in vitro induction system. Here we demonstrate reproducible in vitro Titan cell induction in response to environmental stimuli consistent with the host lung. In vitro Titan cells exhibit all the properties of in vivo generated Titan cells, the current gold standard, including altered capsule, cell wall, size, high mother cell ploidy, and aneuploid progeny. We identify the bacterial peptidoglycan subunit Muramyl Dipeptide as a serum compound associated with shift in cell size and ploidy, and demonstrate the capacity of bronchial lavage fluid and bacterial co-culture to induce Titanisation. Additionally, we demonstrate the capacity of our assay to identify established (cAMP/PKA) and previously undescribed (USV101) regulators of Titanisation in vitro. Finally, we investigate the Titanisation capacity of clinical isolates and their impact on disease outcome. Together, these findings provide new insight into the environmental stimuli and molecular mechanisms underlying the yeast-to-Titan transition and establish an essential in vitro model for the future characterization of this important morphotype.
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Affiliation(s)
- Ivy M. Dambuza
- Medical Research Council Centre for Medical Mycology at the University of Aberdeen, Aberdeen Fungal Group, Institute of Medical Sciences, Foresterhill, Aberdeen, United Kingdom
| | - Thomas Drake
- Medical Research Council Centre for Medical Mycology at the University of Aberdeen, Aberdeen Fungal Group, Institute of Medical Sciences, Foresterhill, Aberdeen, United Kingdom
| | - Ambre Chapuis
- Medical Research Council Centre for Medical Mycology at the University of Aberdeen, Aberdeen Fungal Group, Institute of Medical Sciences, Foresterhill, Aberdeen, United Kingdom
| | - Xin Zhou
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Edgbaston, United Kingdom
| | - Joao Correia
- Medical Research Council Centre for Medical Mycology at the University of Aberdeen, Aberdeen Fungal Group, Institute of Medical Sciences, Foresterhill, Aberdeen, United Kingdom
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Edgbaston, United Kingdom
| | - Leanne Taylor-Smith
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Edgbaston, United Kingdom
| | - Nathalie LeGrave
- Marine Biodiscovery Centre, Department of Chemistry, University of Aberdeen, Aberdeen, United Kingdom
- Francis Crick Institute, London, United Kingdom
| | - Tim Rasmussen
- Marine Biodiscovery Centre, Department of Chemistry, University of Aberdeen, Aberdeen, United Kingdom
- Institut für Biochemie, Universität Würzburg, Wurzburg, Germany
| | - Matthew C. Fisher
- Dpt. Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Tihana Bicanic
- Institute of Infection and Immunity, St George’s University of London, London, United Kingdom
| | - Thomas S. Harrison
- Institute of Infection and Immunity, St George’s University of London, London, United Kingdom
| | - Marcel Jaspars
- Marine Biodiscovery Centre, Department of Chemistry, University of Aberdeen, Aberdeen, United Kingdom
| | - Robin C. May
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Edgbaston, United Kingdom
| | - Gordon D. Brown
- Medical Research Council Centre for Medical Mycology at the University of Aberdeen, Aberdeen Fungal Group, Institute of Medical Sciences, Foresterhill, Aberdeen, United Kingdom
| | - Raif Yuecel
- Medical Research Council Centre for Medical Mycology at the University of Aberdeen, Aberdeen Fungal Group, Institute of Medical Sciences, Foresterhill, Aberdeen, United Kingdom
| | - Donna M. MacCallum
- Medical Research Council Centre for Medical Mycology at the University of Aberdeen, Aberdeen Fungal Group, Institute of Medical Sciences, Foresterhill, Aberdeen, United Kingdom
| | - Elizabeth R. Ballou
- Medical Research Council Centre for Medical Mycology at the University of Aberdeen, Aberdeen Fungal Group, Institute of Medical Sciences, Foresterhill, Aberdeen, United Kingdom
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Edgbaston, United Kingdom
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31
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Fan Y, Lin X. Multiple Applications of a Transient CRISPR-Cas9 Coupled with Electroporation (TRACE) System in the Cryptococcus neoformans Species Complex. Genetics 2018; 208:1357-1372. [PMID: 29444806 PMCID: PMC5887135 DOI: 10.1534/genetics.117.300656] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 02/07/2018] [Indexed: 12/30/2022] Open
Abstract
Cryptococcus neoformans is a fungal pathogen that claims hundreds of thousands of lives annually. Targeted genetic manipulation through biolistic transformation in C. neoformans drove the investigation of this clinically important pathogen at the molecular level. Although costly and inefficient, biolistic transformation remains the major method for editing the Cryptococcus genome as foreign DNAs introduced by other methods such as electroporation are predominantly not integrated into the genome. Although the majority of DNAs introduced by biolistic transformation are stably inherited, the transformation efficiency and the homologous integration rate (∼1-10%) are low. Here, we developed a Transient CRISPR (clustered regularly interspaced short palindromic repeat)-Cas9 coupled with Electroporation (TRACE) system for targeted genetic manipulations in the C. neoformans species complex. This method took advantages of efficient genome integration due to double-strand breaks created at specific sites by the transient CRISPR-Cas9 system and the high transformation efficiency of electroporation. We demonstrated that TRACE can efficiently generate precise single-gene deletion mutants using the ADE2 locus as an example. This system can also effectively delete multiple genes in a single transformation, as evident by the successful generation of quadruple mfα1Δ2Δ3Δ4Δ mutants. In addition to generating gene deletion mutants, we complemented the ade2Δ mutant by integrating a wild-type ADE2 allele at the "safe haven" region (SH2) via homologous recombination using TRACE. Interestingly, introduced DNAs can be inserted at a designated genetic site without any homologous sequences, opening up numerous other applications. We expect that TRACE, an efficient, versatile, and cost-effective gene editing approach, will greatly accelerate research in this field.
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Affiliation(s)
- Yumeng Fan
- Department of Microbiology, University of Georgia, Athens, Georgia 30602
| | - Xiaorong Lin
- Department of Microbiology, University of Georgia, Athens, Georgia 30602
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32
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Fungal G-protein-coupled receptors: mediators of pathogenesis and targets for disease control. Nat Microbiol 2018; 3:402-414. [DOI: 10.1038/s41564-018-0127-5] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 02/09/2018] [Indexed: 12/31/2022]
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33
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Ries LNA, Beattie S, Cramer RA, Goldman GH. Overview of carbon and nitrogen catabolite metabolism in the virulence of human pathogenic fungi. Mol Microbiol 2017; 107:277-297. [PMID: 29197127 DOI: 10.1111/mmi.13887] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 11/20/2017] [Accepted: 11/23/2017] [Indexed: 12/12/2022]
Abstract
It is estimated that fungal infections, caused most commonly by Candida albicans, Aspergillus fumigatus and Cryptococcus neoformans, result in more deaths annually than malaria or tuberculosis. It has long been hypothesized the fungal metabolism plays a critical role in virulence though specific nutrient sources utilized by human pathogenic fungi in vivo has remained enigmatic. However, the metabolic utilisation of preferred carbon and nitrogen sources, encountered in a host niche-dependent manner, is known as carbon catabolite and nitrogen catabolite repression (CCR, NCR), and has been shown to be important for virulence. Several sensory and uptake systems exist, including carbon and nitrogen source-specific sensors and transporters, that allow scavenging of preferred nutrient sources. Subsequent metabolic utilisation is governed by transcription factors, whose functions and essentiality differ between fungal species. Furthermore, additional factors exist that contribute to the implementation of CCR and NCR. The role of the CCR and NCR-related factors in virulence varies greatly between fungal species and a substantial gap in knowledge exists regarding specific pathways. Further elucidation of carbon and nitrogen metabolism mechanisms is therefore required in a fungal species- and animal model-specific manner in order to screen for targets that are potential candidates for anti-fungal drug development.
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Affiliation(s)
- Laure Nicolas Annick Ries
- Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes, Ribeirão Preto, São Paulo, 3900, CEP 14049-900, Brazil
| | - Sarah Beattie
- Department of Microbiology & Immunology, Geisel School of Medicine at Dartmouth, 74 College Street Remsen 213, Hanover, NH 03755, USA
| | - Robert A Cramer
- Department of Microbiology & Immunology, Geisel School of Medicine at Dartmouth, 74 College Street Remsen 213, Hanover, NH 03755, USA
| | - Gustavo H Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Avenida do Café s/n°, Ribeirão Preto, São Paulo, CEP 14040903, Brazil
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34
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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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35
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Song Y, Laureijssen-van de Sande WWJ, Moreno LF, Gerrits van den Ende B, Li R, de Hoog S. Comparative Ecology of Capsular Exophiala Species Causing Disseminated Infection in Humans. Front Microbiol 2017; 8:2514. [PMID: 29312215 PMCID: PMC5742258 DOI: 10.3389/fmicb.2017.02514] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 12/04/2017] [Indexed: 12/15/2022] Open
Abstract
Exophiala spinifera and Exophiala dermatitidis (Fungi: Chaetothyriales) are black yeast agents potentially causing disseminated infection in apparently healthy humans. They are the only Exophiala species producing extracellular polysaccharides around yeast cells. In order to gain understanding of eventual differences in intrinsic virulence of the species, their clinical profiles were compared and found to be different, suggesting pathogenic strategies rather than coincidental opportunism. Ecologically relevant factors were compared in a model set of strains of both species, and significant differences were found in clinical and environmental preferences, but virulence, tested in Galleria mellonella larvae, yielded nearly identical results. Virulence factors, i.e., melanin, capsule and muriform cells responded in opposite direction under hydrogen peroxide and temperature stress and thus were inconsistent with their hypothesized role in survival of phagocytosis. On the basis of physiological profiles, possible natural habitats of both species were extrapolated, which proved to be environmental rather than animal-associated. Using comparative genomic analyses we found differences in gene content related to lipid metabolism, cell wall modification and polysaccharide capsule production. Despite the fact that both species cause disseminated infections in apparently healthy humans, it is concluded that they are opportunists rather than pathogens.
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Affiliation(s)
- Yinggai Song
- Department of Dermatology, Peking University First Hospital, Beijing, China.,Research Center for Medical Mycology, Peking University, Beijing, China.,Beijing Key Laboratory of Molecular Diagnosis of Dermatoses, Peking University First Hospital, Beijing, China.,Westerdijk Fungal Biodiversity Institute, Utrecht, Netherlands
| | | | | | | | - Ruoyu Li
- Department of Dermatology, Peking University First Hospital, Beijing, China.,Research Center for Medical Mycology, Peking University, Beijing, China.,Beijing Key Laboratory of Molecular Diagnosis of Dermatoses, Peking University First Hospital, Beijing, China
| | - Sybren de Hoog
- Westerdijk Fungal Biodiversity Institute, Utrecht, Netherlands.,Center of Expertise in Mycology Radboudumc/CWZ, Radboud University Nijmegen Medical Center, Nijmegen, Netherlands
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36
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Sherrington SL, Kumwenda P, Kousser C, Hall RA. Host Sensing by Pathogenic Fungi. ADVANCES IN APPLIED MICROBIOLOGY 2017; 102:159-221. [PMID: 29680125 DOI: 10.1016/bs.aambs.2017.10.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The ability to cause disease extends from the ability to grow within the host environment. The human host provides a dynamic environment to which fungal pathogens must adapt to in order to survive. The ability to grow under a particular condition (i.e., the ability to grow at mammalian body temperature) is considered a fitness attribute and is essential for growth within the human host. On the other hand, some environmental conditions activate signaling mechanisms resulting in the expression of virulence factors, which aid pathogenicity. Therefore, pathogenic fungi have evolved fitness and virulence attributes to enable them to colonize and infect humans. This review highlights how some of the major pathogenic fungi respond and adapt to key environmental signals within the human host.
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Affiliation(s)
- Sarah L Sherrington
- Institute for Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Pizga Kumwenda
- Institute for Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Courtney Kousser
- Institute for Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Rebecca A Hall
- Institute for Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, United Kingdom.
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37
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Abstract
To respond to the changing environment, cells must be able to sense external conditions. This is important for many processes including growth, mating, the expression of virulence factors, and several other regulatory effects. Nutrient sensing at the plasma membrane is mediated by different classes of membrane proteins that activate downstream signaling pathways: nontransporting receptors, transceptors, classical and nonclassical G-protein-coupled receptors, and the newly defined extracellular mucin receptors. Nontransporting receptors have the same structure as transport proteins, but have lost the capacity to transport while gaining a receptor function. Transceptors are transporters that also function as a receptor, because they can rapidly activate downstream signaling pathways. In this review, we focus on these four types of fungal membrane proteins. We mainly discuss the sensing mechanisms relating to sugars, ammonium, and amino acids. Mechanisms for other nutrients, such as phosphate and sulfate, are discussed briefly. Because the model yeast Saccharomyces cerevisiae has been the most studied, especially regarding these nutrient-sensing systems, each subsection will commence with what is known in this species.
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Zhu LB, Wang Y, Zhang ZB, Yang HL, Yan RM, Zhu D. Influence of environmental and nutritional conditions on yeast–mycelial dimorphic transition in Trichosporon cutaneum. BIOTECHNOL BIOTEC EQ 2017. [DOI: 10.1080/13102818.2017.1292149] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Affiliation(s)
- Li Bin Zhu
- Key Laboratory of Protection and Utilization of Subtropic Plant Resources of Jiangxi Province, Jiangxi Normal University, Nanchang, China
| | - Ya Wang
- Key Lab of Bioprocess Engineering of Jiangxi Province, College of life sciences, Jiangxi Science and Technology Normal University, Nanchang, China
- School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Zhi Bin Zhang
- Key Laboratory of Protection and Utilization of Subtropic Plant Resources of Jiangxi Province, Jiangxi Normal University, Nanchang, China
| | - Hui Lin Yang
- Key Laboratory of Protection and Utilization of Subtropic Plant Resources of Jiangxi Province, Jiangxi Normal University, Nanchang, China
| | - Ri Ming Yan
- Key Laboratory of Protection and Utilization of Subtropic Plant Resources of Jiangxi Province, Jiangxi Normal University, Nanchang, China
| | - Du Zhu
- Key Laboratory of Protection and Utilization of Subtropic Plant Resources of Jiangxi Province, Jiangxi Normal University, Nanchang, China
- Key Lab of Bioprocess Engineering of Jiangxi Province, College of life sciences, Jiangxi Science and Technology Normal University, Nanchang, China
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Bresso E, Togawa R, Hammond-Kosack K, Urban M, Maigret B, Martins NF. GPCRs from fusarium graminearum detection, modeling and virtual screening - the search for new routes to control head blight disease. BMC Bioinformatics 2016; 17:463. [PMID: 28105916 PMCID: PMC5249037 DOI: 10.1186/s12859-016-1342-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
BACKGOUND Fusarium graminearum (FG) is one of the major cereal infecting pathogens causing high economic losses worldwide and resulting in adverse effects on human and animal health. Therefore, the development of new fungicides against FG is an important issue to reduce cereal infection and economic impact. In the strategy for developing new fungicides, a critical step is the identification of new targets against which innovative chemicals weapons can be designed. As several G-protein coupled receptors (GPCRs) are implicated in signaling pathways critical for the fungi development and survival, such proteins could be valuable efficient targets to reduce Fusarium growth and therefore to prevent food contamination. RESULTS In this study, GPCRs were predicted in the FG proteome using a manually curated pipeline dedicated to the identification of GPCRs. Based on several successive filters, the most appropriate GPCR candidate target for developing new fungicides was selected. Searching for new compounds blocking this particular target requires the knowledge of its 3D-structure. As no experimental X-Ray structure of the selected protein was available, a 3D model was built by homology modeling. The model quality and stability was checked by 100 ns of molecular dynamics simulations. Two stable conformations representative of the conformational families of the protein were extracted from the 100 ns simulation and were used for an ensemble docking campaign. The model quality and stability was checked by 100 ns of molecular dynamics simulations previously to the virtual screening step. The virtual screening step comprised the exploration of a chemical library with 11,000 compounds that were docked to the GPCR model. Among these compounds, we selected the ten top-ranked nontoxic molecules proposed to be experimentally tested to validate the in silico simulation. CONCLUSIONS This study provides an integrated process merging genomics, structural bioinformatics and drug design for proposing innovative solutions to a world wide threat to grain producers and consumers.
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Affiliation(s)
- Emmanuel Bresso
- EMBRAPA Genetic Resources and Biotechnology, Brasília, DF 70770-917 Brazil
| | - Roberto Togawa
- EMBRAPA Genetic Resources and Biotechnology, Brasília, DF 70770-917 Brazil
| | - Kim Hammond-Kosack
- Department of Plant Biology and Crop Science, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ UK
| | - Martin Urban
- Department of Plant Biology and Crop Science, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ UK
| | - Bernard Maigret
- EMBRAPA Genetic Resources and Biotechnology, Brasília, DF 70770-917 Brazil
- CAPSID Team, LORIA, UMR 7503, CNRS, Lorraine University, Vandœuvre-lès-Nancy, 54506 France
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Abdulkareem AF, Lee HH, Ahmadi M, Martinez LR. Fungal serotype-specific differences in bacterial-yeast interactions. Virulence 2016; 6:652-7. [PMID: 26132337 DOI: 10.1080/21505594.2015.1066962] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Cryptococcus neoformans (Cn) causes meningoencephalitis in immunocompromised individuals. This encapsulated fungus can be found interacting with environmental microbes in soil contaminated with pigeon excrement. Cn survival within polymicrobial and other challenging communities has been shown to affect the evolution of its virulence factors. We compared the survival of 10 serotype A and D strains after interaction with the soil bacterium, Acinetobacter baumannii (Ab). Although co-incubation with Ab stimulated virulence factors production by strains of both cryptococcal serotypes, on average, serotype A strains displayed significantly higher survival rate, number of metabolically active cells within biofilms, and capsular polysaccharide production and release than serotype D strains. Our findings suggest that interactions of Cn with other microorganisms influence the fungus' regulation and production of virulence factors, important elements needed for the successful colonization of the human host.
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Affiliation(s)
- Asan F Abdulkareem
- a Department of Biology ; Faculty of Sciences and Health ; Koya University , Koya-Erbil , Iraq
| | - Hiu Ham Lee
- b Department of Biomedical Sciences ; NYIT College of Osteopathic Medicine ; New York Institute of Technology , Old Westbury , NY USA
| | - Mohammed Ahmadi
- c Department of Biology ; Adelphi University , Garden City , NY USA
| | - Luis R Martinez
- b Department of Biomedical Sciences ; NYIT College of Osteopathic Medicine ; New York Institute of Technology , Old Westbury , NY USA
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Braunsdorf C, Mailänder-Sánchez D, Schaller M. Fungal sensing of host environment. Cell Microbiol 2016; 18:1188-200. [DOI: 10.1111/cmi.12610] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 05/02/2016] [Accepted: 05/05/2016] [Indexed: 12/13/2022]
Affiliation(s)
- C. Braunsdorf
- Department of Dermatology; University Hospital Tübingen; Liebermeisterstr. 25 Tübingen Germany
| | - D. Mailänder-Sánchez
- Department of Internal Medicine I; University Hospital Tübingen; Otfried-Müller-Straße 10 72076 Tübingen
| | - M. Schaller
- Department of Dermatology; University Hospital Tübingen; Liebermeisterstr. 25 Tübingen Germany
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Assessing the relevance of light for fungi: Implications and insights into the network of signal transmission. ADVANCES IN APPLIED MICROBIOLOGY 2016; 76:27-78. [PMID: 21924971 DOI: 10.1016/b978-0-12-387048-3.00002-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Light represents an important environmental cue, which provides information enabling fungi to prepare and react to the different ambient conditions between day and night. This adaptation requires both anticipation of the changing conditions, which is accomplished by daily rhythmicity of gene expression brought about by the circadian clock, and reaction to sudden illumination. Besides perception of the light signal, also integration of this signal with other environmental cues, most importantly nutrient availability, necessitates light-dependent regulation of signal transduction pathways and metabolic pathways. An influence of light and/or the circadian clock is known for the cAMP pathway, heterotrimeric G-protein signaling, mitogen-activated protein kinases, two-component phosphorelays, and Ca(2+) signaling. Moreover, also the target of rapamycin signaling pathway and reactive oxygen species as signal transducing elements are assumed to be connected to the light-response pathway. The interplay of the light-response pathway with signaling cascades results in light-dependent regulation of primary and secondary metabolism, morphology, development, biocontrol activity, and virulence. The frequent use of fungi in biotechnology as well as analysis of fungi in the artificial environment of a laboratory therefore requires careful consideration of still operative evolutionary heritage of these organisms. This review summarizes the diverse effects of light on fungi and the mechanisms they apply to deal both with the information content and with the harmful properties of light. Additionally, the implications of the reaction of fungi to light in a laboratory environment for experimental work and industrial applications are discussed.
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Analysis of the Protein Kinase A-Regulated Proteome of Cryptococcus neoformans Identifies a Role for the Ubiquitin-Proteasome Pathway in Capsule Formation. mBio 2016; 7:e01862-15. [PMID: 26758180 PMCID: PMC4725006 DOI: 10.1128/mbio.01862-15] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The opportunistic fungal pathogen Cryptococcus neoformans causes life-threatening meningitis in immunocompromised individuals. The expression of virulence factors, including capsule and melanin, is in part regulated by the cyclic-AMP/protein kinase A (cAMP/PKA) signal transduction pathway. In this study, we investigated the influence of PKA on the composition of the intracellular proteome to obtain a comprehensive understanding of the regulation that underpins virulence. Through quantitative proteomics, enrichment and bioinformatic analyses, and an interactome study, we uncovered a pattern of PKA regulation for proteins associated with translation, the proteasome, metabolism, amino acid biosynthesis, and virulence-related functions. PKA regulation of the ubiquitin-proteasome pathway in C. neoformans showed a striking parallel with connections between PKA and protein degradation in chronic neurodegenerative disorders and other human diseases. Further investigation of proteasome function with the inhibitor bortezomib revealed an impact on capsule production as well as hypersusceptibility for strains with altered expression or activity of PKA. Parallel studies with tunicamycin also linked endoplasmic reticulum stress with capsule production and PKA. Taken together, the data suggest a model whereby expression of PKA regulatory and catalytic subunits and the activation of PKA influence proteostasis and the function of the endoplasmic reticulum to control the elaboration of the polysaccharide capsule. Overall, this study revealed both broad and conserved influences of the cAMP/PKA pathway on the proteome and identified proteostasis as a potential therapeutic target for the treatment of cryptococcosis. Fungi cause life-threatening diseases, but very few drugs are available to effectively treat fungal infections. The pathogenic fungus Cryptococcus neoformans causes a substantial global burden of life-threatening meningitis in patients suffering from HIV/AIDS. An understanding of the mechanisms by which fungi deploy virulence factors to cause disease is critical for developing new therapeutic approaches. We employed a quantitative proteomic approach to define the changes in the protein complement that occur upon modulating the cAMP signaling pathway that regulates virulence in C. neoformans. This approach identified a conserved role for cAMP signaling in the regulation of the ubiquitin-proteasome pathway and revealed a link between this pathway and elaboration of a major virulence determinant, the polysaccharide capsule. Targeting the ubiquitin-proteasome pathway opens new therapeutic options for the treatment of cryptococcosis.
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45
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Chacko N, Zhao Y, Yang E, Wang L, Cai JJ, Lin X. The lncRNA RZE1 Controls Cryptococcal Morphological Transition. PLoS Genet 2015; 11:e1005692. [PMID: 26588844 PMCID: PMC4654512 DOI: 10.1371/journal.pgen.1005692] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 10/30/2015] [Indexed: 02/01/2023] Open
Abstract
In the fungal pathogen Cryptococcus neoformans, the switch from yeast to hypha is an important morphological process preceding the meiotic events during sexual development. Morphotype is also known to be associated with cryptococcal virulence potential. Previous studies identified the regulator Znf2 as a key decision maker for hypha formation and as an anti-virulence factor. By a forward genetic screen, we discovered that a long non-coding RNA (lncRNA) RZE1 functions upstream of ZNF2 in regulating yeast-to-hypha transition. We demonstrate that RZE1 functions primarily in cis and less effectively in trans. Interestingly, RZE1's function is restricted to its native nucleus. Accordingly, RZE1 does not appear to directly affect Znf2 translation or the subcellular localization of Znf2 protein. Transcriptome analysis indicates that the loss of RZE1 reduces the transcript level of ZNF2 and Znf2's prominent downstream targets. In addition, microscopic examination using single molecule fluorescent in situ hybridization (smFISH) indicates that the loss of RZE1 increases the ratio of ZNF2 transcripts in the nucleus versus those in the cytoplasm. Taken together, this lncRNA controls Cryptococcus yeast-to-hypha transition through regulating the key morphogenesis regulator Znf2. This is the first functional characterization of a lncRNA in a human fungal pathogen. Given the potential large number of lncRNAs in the genomes of Cryptococcus and other fungal pathogens, the findings implicate lncRNAs as an additional layer of genetic regulation during fungal development that may well contribute to the complexity in these "simple" eukaryotes.
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Affiliation(s)
- Nadia Chacko
- Department of Biology, Texas A&M University, College Station, Texas, United States of America
| | - Youbao Zhao
- Department of Biology, Texas A&M University, College Station, Texas, United States of America
| | - Ence Yang
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, United States of America
| | - Linqi Wang
- Department of Biology, Texas A&M University, College Station, Texas, United States of America
| | - James J. Cai
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, United States of America
| | - Xiaorong Lin
- Department of Biology, Texas A&M University, College Station, Texas, United States of America
- * E-mail:
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46
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Brown NA, Dos Reis TF, Ries LNA, Caldana C, Mah JH, Yu JH, Macdonald JM, Goldman GH. G-protein coupled receptor-mediated nutrient sensing and developmental control in Aspergillus nidulans. Mol Microbiol 2015; 98:420-39. [PMID: 26179439 DOI: 10.1111/mmi.13135] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/14/2015] [Indexed: 12/31/2022]
Abstract
Nutrient sensing and utilisation are fundamental for all life forms. As heterotrophs, fungi have evolved a diverse range of mechanisms for sensing and taking up various nutrients. Despite its importance, only a limited number of nutrient receptors and their corresponding ligands have been identified in fungi. G-protein coupled receptors (GPCRs) are the largest family of transmembrane receptors. The Aspergillus nidulans genome encodes 16 putative GPCRs, but only a few have been functionally characterised. Our previous study showed the increased expression of an uncharacterised putative GPCR, gprH, during carbon starvation. GprH appears conserved throughout numerous filamentous fungi. Here, we reveal that GprH is a putative receptor involved in glucose and tryptophan sensing. The absence of GprH results in a reduction in cAMP levels and PKA activity upon adding glucose or tryptophan to starved cells. GprH is pre-formed in conidia and is increasingly active during carbon starvation, where it plays a role in glucose uptake and the recovery of hyphal growth. GprH also represses sexual development under conditions favouring sexual fruiting and during carbon starvation in submerged cultures. In summary, the GprH nutrient-sensing system functions upstream of the cAMP-PKA pathway, influences primary metabolism and hyphal growth, while represses sexual development in A. nidulans.
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Affiliation(s)
- Neil Andrew Brown
- Plant Biology and Crop Science, Rothamsted Research, Harpenden, Herts, AL5 2JQ, UK
| | - Thaila Fernanda Dos Reis
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
| | | | - Camila Caldana
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol - CTBE, Campinas, São Paulo, Brazil.,Max Planck Partnergroup at CTBE/CNPEM, Campinas, São Paulo, Brazil
| | - Jae-Hyung Mah
- Department of Food and Biotechnology, Korea University, Sejong, South Korea
| | - Jae-Hyuk Yu
- Department of Bacteriology, University of Wisconsin, Madison, WI, USA
| | - Jeffrey M Macdonald
- UNC Metabolomic Facility, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Gustavo Henrique Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil.,Laboratório Nacional de Ciência e Tecnologia do Bioetanol - CTBE, Campinas, São Paulo, Brazil
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Choi J, Jung WH, Kronstad JW. The cAMP/protein kinase A signaling pathway in pathogenic basidiomycete fungi: Connections with iron homeostasis. J Microbiol 2015; 53:579-87. [PMID: 26231374 DOI: 10.1007/s12275-015-5247-5] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Revised: 07/03/2015] [Accepted: 07/03/2015] [Indexed: 12/26/2022]
Abstract
A number of pathogenic species of basidiomycete fungi are either life-threatening pathogens of humans or major economic pests for crop production. Sensing the host is a key aspect of pathogen proliferation during disease, and signal transduction pathways are critically important for detecting environmental conditions and facilitating adaptation. This review focuses on the contributions of the cAMP/protein kinase A (PKA) signaling pathway in Cryptococcus neoformans, a species that causes meningitis in humans, and Ustilago maydis, a model phytopathogen that causes a smut disease on maize. Environmental sensing by the cAMP/PKA pathway regulates the production of key virulence traits in C. neoformans including the polysaccharide capsule and melanin. For U. maydis, the pathway controls the dimorphic transition from budding growth to the filamentous cell type required for proliferation in plant tissue. We discuss recent advances in identifying new components of the cAMP/PKA pathway in these pathogens and highlight an emerging theme that pathway signaling influences iron acquisition.
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Affiliation(s)
- Jaehyuk Choi
- Division of Life Sciences, and Culture Collection and DNA Bank of Mushrooms, Incheon National University, Incheon, 406-772, Republic of Korea
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48
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Polvi EJ, Li X, O’Meara TR, Leach MD, Cowen LE. Opportunistic yeast pathogens: reservoirs, virulence mechanisms, and therapeutic strategies. Cell Mol Life Sci 2015; 72:2261-87. [PMID: 25700837 PMCID: PMC11113693 DOI: 10.1007/s00018-015-1860-z] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Revised: 02/06/2015] [Accepted: 02/11/2015] [Indexed: 12/21/2022]
Abstract
Life-threatening invasive fungal infections are becoming increasingly common, at least in part due to the prevalence of medical interventions resulting in immunosuppression. Opportunistic fungal pathogens of humans exploit hosts that are immunocompromised, whether by immunosuppression or genetic predisposition, with infections originating from either commensal or environmental sources. Fungal pathogens are armed with an arsenal of traits that promote pathogenesis, including the ability to survive host physiological conditions and to switch between different morphological states. Despite the profound impact of fungal pathogens on human health worldwide, diagnostic strategies remain crude and treatment options are limited, with resistance to antifungal drugs on the rise. This review will focus on the global burden of fungal infections, the reservoirs of these pathogens, the traits of opportunistic yeast that lead to pathogenesis, host genetic susceptibilities, and the challenges that must be overcome to combat antifungal drug resistance and improve clinical outcome.
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Affiliation(s)
- Elizabeth J. Polvi
- Department of Molecular Genetics, University of Toronto, 1 King’s College Circle, Medical Sciences Building, Room 4368, Toronto, ON M5S 1A8 Canada
| | - Xinliu Li
- Department of Molecular Genetics, University of Toronto, 1 King’s College Circle, Medical Sciences Building, Room 4368, Toronto, ON M5S 1A8 Canada
| | - Teresa R. O’Meara
- Department of Molecular Genetics, University of Toronto, 1 King’s College Circle, Medical Sciences Building, Room 4368, Toronto, ON M5S 1A8 Canada
| | - Michelle D. Leach
- Department of Molecular Genetics, University of Toronto, 1 King’s College Circle, Medical Sciences Building, Room 4368, Toronto, ON M5S 1A8 Canada
- Aberdeen Fungal Group, Institute of Medical Sciences, School of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, UK
| | - Leah E. Cowen
- Department of Molecular Genetics, University of Toronto, 1 King’s College Circle, Medical Sciences Building, Room 4368, Toronto, ON M5S 1A8 Canada
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Zhang N, Park YD, Williamson PR. New technology and resources for cryptococcal research. Fungal Genet Biol 2015; 78:99-107. [PMID: 25460849 PMCID: PMC4433448 DOI: 10.1016/j.fgb.2014.11.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Revised: 11/02/2014] [Accepted: 11/06/2014] [Indexed: 11/26/2022]
Abstract
Rapid advances in molecular biology and genome sequencing have enabled the generation of new technology and resources for cryptococcal research. RNAi-mediated specific gene knock down has become routine and more efficient by utilizing modified shRNA plasmids and convergent promoter RNAi constructs. This system was recently applied in a high-throughput screen to identify genes involved in host-pathogen interactions. Gene deletion efficiencies have also been improved by increasing rates of homologous recombination through a number of approaches, including a combination of double-joint PCR with split-marker transformation, the use of dominant selectable markers and the introduction of Cre-Loxp systems into Cryptococcus. Moreover, visualization of cryptococcal proteins has become more facile using fusions with codon-optimized fluorescent tags, such as green or red fluorescent proteins or, mCherry. Using recent genome-wide analytical tools, new transcriptional factors and regulatory proteins have been identified in novel virulence-related signaling pathways by employing microarray analysis, RNA-sequencing and proteomic analysis.
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Affiliation(s)
- Nannan Zhang
- Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institution of Health, Bethesda, MD, United States
| | - Yoon-Dong Park
- Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institution of Health, Bethesda, MD, United States
| | - Peter R Williamson
- Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institution of Health, Bethesda, MD, United States.
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Ost KS, O’Meara TR, Huda N, Esher SK, Alspaugh JA. The Cryptococcus neoformans alkaline response pathway: identification of a novel rim pathway activator. PLoS Genet 2015; 11:e1005159. [PMID: 25859664 PMCID: PMC4393102 DOI: 10.1371/journal.pgen.1005159] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Accepted: 03/19/2015] [Indexed: 12/28/2022] Open
Abstract
The Rim101/PacC transcription factor acts in a fungal-specific signaling pathway responsible for sensing extracellular pH signals. First characterized in ascomycete fungi such as Aspergillus nidulans and Saccharomyces cerevisiae, the Rim/Pal pathway maintains conserved features among very distantly related fungi, where it coordinates cellular adaptation to alkaline pH signals and micronutrient deprivation. However, it also directs species-specific functions in fungal pathogens such as Cryptococcus neoformans, where it controls surface capsule expression. Moreover, disruption of the Rim pathway central transcription factor, Rim101, results in a strain that causes a hyper-inflammatory response in animal infection models. Using targeted gene deletions, we demonstrate that several genes encoding components of the classical Rim/Pal pathway are present in the C. neoformans genome. Many of these genes are in fact required for Rim101 activation, including members of the ESCRT complex (Vps23 and Snf7), ESCRT-interacting proteins (Rim20 and Rim23), and the predicted Rim13 protease. We demonstrate that in neutral/alkaline pH, Rim23 is recruited to punctate regions on the plasma membrane. This change in Rim23 localization requires upstream ESCRT complex components but does not require other Rim101 proteolysis components, such as Rim20 or Rim13. Using a forward genetics screen, we identified the RRA1 gene encoding a novel membrane protein that is also required for Rim101 protein activation and, like the ESCRT complex, is functionally upstream of Rim23-membrane localization. Homologs of RRA1 are present in other Cryptococcus species as well as other basidiomycetes, but closely related genes are not present in ascomycetes. These findings suggest that major branches of the fungal Kingdom developed different mechanisms to sense and respond to very elemental extracellular signals such as changing pH levels.
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Affiliation(s)
- Kyla S. Ost
- Departments of Medicine/ Molecular Genetics & Microbiology, Duke University School of Medicine, Durham, North Carolina, United States of America
| | - Teresa R. O’Meara
- Departments of Medicine/ Molecular Genetics & Microbiology, Duke University School of Medicine, Durham, North Carolina, United States of America
| | - Naureen Huda
- Departments of Medicine/ Molecular Genetics & Microbiology, Duke University School of Medicine, Durham, North Carolina, United States of America
| | - Shannon K. Esher
- Departments of Medicine/ Molecular Genetics & Microbiology, Duke University School of Medicine, Durham, North Carolina, United States of America
| | - J. Andrew Alspaugh
- Departments of Medicine/ Molecular Genetics & Microbiology, Duke University School of Medicine, Durham, North Carolina, United States of America
- * E-mail:
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