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Wang D, Zeng N, Li C, Li Z, Zhang N, Li B. Fungal biofilm formation and its regulatory mechanism. Heliyon 2024; 10:e32766. [PMID: 38988529 PMCID: PMC11233959 DOI: 10.1016/j.heliyon.2024.e32766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2023] [Revised: 06/07/2024] [Accepted: 06/08/2024] [Indexed: 07/12/2024] Open
Abstract
Fungal biofilm is a microbial community composed of fungal cells and extracellular polymeric substances (EPS). In recent years, fungal biofilms have played an increasingly important role in many fields. However, there are few studies on fungal biofilms and their related applications and development are still far from enough. Therefore, this review summarizes the composition and function of EPS in fungal biofilms, and improves and refines the formation process of fungal biofilms according to the latest viewpoints. Moreover, based on the study of Saccharomyces cerevisiae and Candida albicans, this review summarizes the gene regulation network of fungal biofilm synthesis, which is crucial for systematically understanding the molecular mechanism of fungal biofilm formation. It is of great significance to further develop effective methods at the molecular level to control harmful biofilms or enhance and regulate the formation of beneficial biofilms. Finally, the quorum sensing factors and mixed biofilms formed by fungi in the current research of fungal biofilms are summarized. These results will help to deepen the understanding of the formation process and internal regulation mechanism of fungal biofilm, provide reference for the study of EPS composition and structure, formation, regulation, group behavior and mixed biofilm formation of other fungal biofilms, and provide strategies and theoretical basis for the control, development and utilization of fungal biofilms.
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Affiliation(s)
- Dandan Wang
- College of Land and Environment, Shenyang Agricultural University, Shenyang, 110866, PR China
| | - Nan Zeng
- College of Land and Environment, Shenyang Agricultural University, Shenyang, 110866, PR China
| | - Chunji Li
- Innovative Institute for Plant Health, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, PR China
- Key Laboratory of Green Prevention and Control on Fruits and Vegetables in South China, Ministry of Agriculture and Rural Affairs, Guangzhou, 510225, PR China
- College of Agriculture and Biology, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, PR China
| | - Zijing Li
- College of Food Science, Shenyang Agricultural University, Shenyang, 110866, PR China
| | - Ning Zhang
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, PR China
| | - Bingxue Li
- College of Land and Environment, Shenyang Agricultural University, Shenyang, 110866, PR China
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2
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Lohse MB, Ziv N, Johnson AD. Variation in transcription regulator expression underlies differences in white-opaque switching between the SC5314 reference strain and the majority of Candida albicans clinical isolates. Genetics 2023; 225:iyad162. [PMID: 37811798 PMCID: PMC10627253 DOI: 10.1093/genetics/iyad162] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 08/26/2023] [Indexed: 10/10/2023] Open
Abstract
Candida albicans, a normal member of the human microbiome and an opportunistic fungal pathogen, undergoes several morphological transitions. One of these transitions is white-opaque switching, where C. albicans alternates between 2 stable cell types with distinct cellular and colony morphologies, metabolic preferences, mating abilities, and interactions with the innate immune system. White-to-opaque switching is regulated by mating type; it is repressed by the a1/α2 heterodimer in a/α cells, but this repression is lifted in a/a and α/α mating type cells (each of which are missing half of the repressor). The widely used C. albicans reference strain, SC5314, is unusual in that white-opaque switching is completely blocked when the cells are a/α; in contrast, most other C. albicans a/α strains can undergo white-opaque switching at an observable level. In this paper, we uncover the reason for this difference. We show that, in addition to repression by the a1/α2 heterodimer, SC5314 contains a second block to white-opaque switching: 4 transcription regulators of filamentous growth are upregulated in this strain and collectively suppress white-opaque switching. This second block is missing in the majority of clinical strains, and, although they still contain the a1/α2 heterodimer repressor, they exhibit a/α white-opaque switching at an observable level. When both blocks are absent, white-opaque switching occurs at very high levels. This work shows that white-opaque switching remains intact across a broad group of clinical strains, but the precise way it is regulated and therefore the frequency at which it occurs varies from strain to strain.
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Affiliation(s)
- Matthew B Lohse
- Department of Microbiology and Immunology, University of California - San Francisco, San Francisco, CA 94143, USA
| | - Naomi Ziv
- Department of Microbiology and Immunology, University of California - San Francisco, San Francisco, CA 94143, USA
| | - Alexander D Johnson
- Department of Microbiology and Immunology, University of California - San Francisco, San Francisco, CA 94143, USA
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3
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Brenes LR, Johnson AD, Lohse MB. Farnesol and phosphorylation of the transcriptional regulator Efg1 affect Candida albicans white-opaque switching rates. PLoS One 2023; 18:e0280233. [PMID: 36662710 PMCID: PMC9858334 DOI: 10.1371/journal.pone.0280233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 12/24/2022] [Indexed: 01/21/2023] Open
Abstract
Candida albicans is a normal member of the human microbiome and an opportunistic fungal pathogen. This species undergoes several morphological transitions, and here we consider white-opaque switching. In this switching program, C. albicans reversibly alternates between two cell types, named "white" and "opaque," each of which is normally stable across thousands of cell divisions. Although switching under most conditions is stochastic and rare, certain environmental signals or genetic manipulations can dramatically increase the rate of switching. Here, we report the identification of two new inputs which affect white-to-opaque switching rates. The first, exposure to sub-micromolar concentrations of (E,E)-farnesol, reduces white-to-opaque switching by ten-fold or more. The second input, an inferred PKA phosphorylation of residue T208 on the transcriptional regulator Efg1, increases white-to-opaque switching ten-fold. Combining these and other environmental inputs results in a variety of different switching rates, indicating that a given rate represents the integration of multiple inputs.
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Affiliation(s)
- Lucas R. Brenes
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, California, United States of America
| | - Alexander D. Johnson
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, California, United States of America
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, California, United States of America
| | - Matthew B. Lohse
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, California, United States of America
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Lyu X, Wang Q, Liu A, Liu F, Meng L, Wang P, Zhang Y, Wang L, Li Z, Wang W. The transcription factor Ste12-like increases the mycelial abiotic stress tolerance and regulates the fruiting body development of Flammulina filiformis. Front Microbiol 2023; 14:1139679. [PMID: 37213522 PMCID: PMC10192742 DOI: 10.3389/fmicb.2023.1139679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Accepted: 03/14/2023] [Indexed: 05/23/2023] Open
Abstract
Introduction Flammulina filiformis is one of the most commercially important edible fungi worldwide, with its nutritional value and medicinal properties. It becomes a good model species to study the tolerance of abiotic stress during mycelia growth in edible mushroom cultivation. Transcription factor Ste12 has been reported to be involved in the regulation of stress tolerance and sexual reproduction in fungi. Methods In this study, identification and phylogenetic analysis of ste12-like was performed by bioinformatics methods. Four ste12-like overexpression transformants of F. filiformis were constructed by Agrobacterium tumefaciens-mediated transformation. Results and Discussion Phylogenetic analysis showed that Ste12-like contained conserved amino acid sequences. All the overexpression transformants were more tolerant to salt stress, cold stress and oxidative stress than wild-type strains. In the fruiting experiment, the number of fruiting bodies of overexpression transformants increased compared with wild-type strains, but the growth rate of stipes slowed down. It suggested that gene ste12-like was involved in the regulation of abiotic stress tolerance and fruiting body development in F. filiformis.
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Affiliation(s)
- Xiaomeng Lyu
- Shandong Provincial Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Tai’an, China
- Mycological Research Center, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Qingji Wang
- Shandong Provincial Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Tai’an, China
| | - Ao Liu
- Shandong Provincial Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Tai’an, China
| | - Fang Liu
- Mycological Research Center, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Li Meng
- Shandong Provincial Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Tai’an, China
| | - Panmeng Wang
- Shandong Provincial Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Tai’an, China
| | - Yan Zhang
- Shandong Provincial Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Tai’an, China
| | - Li Wang
- Shandong Provincial Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Tai’an, China
- *Correspondence: Li Wang,
| | - Zhuang Li
- Shandong Provincial Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Tai’an, China
- Zhuang Li,
| | - Wei Wang
- Shandong Provincial Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Tai’an, China
- Wei Wang,
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Nicoletti G, White K. The Anti-Fungal Activity of Nitropropenyl Benzodioxole (NPBD), a Redox-Thiol Oxidant and Tyrosine Phosphatase Inhibitor. Antibiotics (Basel) 2022; 11:antibiotics11091188. [PMID: 36139967 PMCID: PMC9495065 DOI: 10.3390/antibiotics11091188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 08/28/2022] [Accepted: 08/30/2022] [Indexed: 11/16/2022] Open
Abstract
Phylogenetically diverse fungal species are an increasing cause of severe disease and mortality. Identification of new targets and development of new fungicidal drugs are required to augment the effectiveness of current chemotherapy and counter increasing resistance in pathogens. Nitroalkenyl benzene derivatives are thiol oxidants and inhibitors of cysteine-based molecules, which show broad biological activity against microorganisms. Nitropropenyl benzodioxole (NPBD), one of the most active antimicrobial derivatives, shows high activity in MIC assays for phylogenetically diverse saprophytic, commensal and parasitic fungi. NPBD was fungicidal to all species except the dermatophytic fungi, with an activity profile comparable to that of Amphotericin B and Miconazole. NPBD showed differing patterns of dynamic kill rates under different growth conditions for Candida albicans and Aspergillus fumigatus and was rapidly fungicidal for non-replicating vegetative forms and microconidia. It did not induce resistant or drug tolerant strains in major pathogens on long term exposure. A literature review highlights the complexity and interactivity of fungal tyrosine phosphate and redox signaling pathways, their differing metabolic effects in fungal species and identifies some targets for inhibition. A comparison of the metabolic activities of Amphotericin B, Miconazole and NPBD highlights the multiple cellular functions of these agents and the complementarity of many mechanisms. The activity profile of NPBD illustrates the functional diversity of fungal tyrosine phosphatases and thiol-based redox active molecules and contributes to the validation of tyrosine phosphatases and redox thiol molecules as related and complementary selective targets for antimicrobial drug development. NPBD is a selective antifungal agent with low oral toxicity which would be suitable for local treatment of skin and mucosal infections.
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Yaakoub H, Sanchez NS, Ongay-Larios L, Courdavault V, Calenda A, Bouchara JP, Coria R, Papon N. The high osmolarity glycerol (HOG) pathway in fungi †. Crit Rev Microbiol 2021; 48:657-695. [PMID: 34893006 DOI: 10.1080/1040841x.2021.2011834] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
While fungi are widely occupying nature, many species are responsible for devastating mycosis in humans. Such niche diversity explains how quick fungal adaptation is necessary to endow the capacity of withstanding fluctuating environments and to cope with host-imposed conditions. Among all the molecular mechanisms evolved by fungi, the most studied one is the activation of the phosphorelay signalling pathways, of which the high osmolarity glycerol (HOG) pathway constitutes one of the key molecular apparatus underpinning fungal adaptation and virulence. In this review, we summarize the seminal knowledge of the HOG pathway with its more recent developments. We specifically described the HOG-mediated stress adaptation, with a particular focus on osmotic and oxidative stress, and point out some lags in our understanding of its involvement in the virulence of pathogenic species including, the medically important fungi Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus, compared to the model yeast Saccharomyces cerevisiae. Finally, we also highlighted some possible applications of the HOG pathway modifications to improve the fungal-based production of natural products in the industry.
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Affiliation(s)
- Hajar Yaakoub
- Univ Angers, Univ Brest, GEIHP, SFR ICAT, Angers, France
| | - Norma Silvia Sanchez
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City, Mexico
| | - Laura Ongay-Larios
- Unidad de Biología Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Vincent Courdavault
- EA2106 "Biomolécules et Biotechnologies Végétales", Université de Tours, Tours, France
| | | | | | - Roberto Coria
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City, Mexico
| | - Nicolas Papon
- Univ Angers, Univ Brest, GEIHP, SFR ICAT, Angers, France
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7
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Szabó K, Miskei M, Farkas I, Dombrádi V. The phosphatome of opportunistic pathogen Candida species. FUNGAL BIOL REV 2021. [DOI: 10.1016/j.fbr.2020.12.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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8
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Abstract
In the last decades, Candida albicans has served as the leading causal agent of life-threatening invasive infections with mortality rates approaching 40% despite treatment. Candida albicans (C. albicans) exists in three biological phases: yeast, pseudohyphae, and hyphae. Hyphae, which represent an important phase in the disease process, can cause tissue damage by invading mucosal epithelial cells then leading to blood infection. In this review, we summarized recent results from different fields of fungal cell biology that are instrumental in understanding hyphal growth. This includes research on the differences among C. albicans phases; the regulatory mechanism of hyphal growth, extension, and maintaining cutting-edge polarity; cross regulations of hyphal development and the virulence factors that cause serious infection. With a better understanding of the mechanism on mycelium formation, this review provides a theoretical basis for the identification of targets in candidiasis treatment. It also gives some reference to the study of antifungal drugs.
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Affiliation(s)
- Hui Chen
- State Key Laboratory of Oral Diseases, Sichuan University, Chengdu, China.,Department of Operative Dentistry and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Xuedong Zhou
- State Key Laboratory of Oral Diseases, Sichuan University, Chengdu, China.,Department of Operative Dentistry and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Biao Ren
- State Key Laboratory of Oral Diseases, Sichuan University, Chengdu, China
| | - Lei Cheng
- State Key Laboratory of Oral Diseases, Sichuan University, Chengdu, China.,Department of Operative Dentistry and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
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Yang G, Cao X, Ma G, Qin L, Wu Y, Lin J, Ye P, Yuan J, Wang S. MAPK pathway-related tyrosine phosphatases regulate development, secondary metabolism and pathogenicity in fungus Aspergillus flavus. Environ Microbiol 2020; 22:5232-5247. [PMID: 32813277 DOI: 10.1111/1462-2920.15202] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 08/15/2020] [Accepted: 08/16/2020] [Indexed: 01/12/2023]
Abstract
Mitogen-activated protein kinase (MAPK) cascades are highly conserved in eukaryotic cells and are known to play crucial roles in the regulation of various cellular processes. However, compared with kinase-mediated phosphorylation, dephosphorylation catalysed by phosphatases has not been well characterized in filamentous fungi. In this study, we identified five MAPK pathway-related phosphatases (Msg5, Yvh1, Ptp1, Ptp2 and Oca2) and characterized their functions in Aspergillus flavus, which produces aflatoxin B1 (AFB1 ), one of the most toxic and carcinogenic secondary metabolites. These five phosphatases were identified as negative regulators of MAPK (Slt2, Fus3 and Hog1) pathways. Deletion of Msg5 and Yvh1 resulted in significant defects in conidiation, sclerotia formation, aflatoxin production and crop infection. Additionally, double knockout mutants (ΔMsg5/ΔPtp1, ΔMsg5/ΔPtp2 and ΔMsg5/ΔOca2) displayed similar defects to those observed in the ΔMsg5 single mutant, indicating that Msg5 plays a major role in the regulation of development and pathogenicity in A. flavus. Importantly, we found that the active site at C439 is essential for the function of the Msg5 phosphatase. Furthermore, the MAP kinase Fus3 was found to be involved in the regulation of development, aflatoxin biosynthesis and pathogenicity, and its conserved phosphorylation residues (Thr and Tyr) were critical for the full range of its functions in A. flavus. Overall, our results reveal that MAPK related tyrosine phosphatases play important roles in the regulation of development, secondary metabolism and pathogenicity in A. flavus, and could be developed as potential targets for preventing damage caused by this fungal pathogen.
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Affiliation(s)
- Guang Yang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Xiaohong Cao
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Genli Ma
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Ling Qin
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Yuanzhen Wu
- Department of Applied Biology, East China University of Science and Technology, Shanghai, 200237, China
| | - Jian Lin
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Peng Ye
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Jun Yuan
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Shihua Wang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
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10
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A Set of Diverse Genes Influence the Frequency of White-Opaque Switching in Candida albicans. G3-GENES GENOMES GENETICS 2020; 10:2593-2600. [PMID: 32487674 PMCID: PMC7407467 DOI: 10.1534/g3.120.401249] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The fungal species Candida albicans is both a member of the human microbiome and a fungal pathogen. C. albicans undergoes several different morphological transitions, including one called white-opaque switching. Here, cells reversibly switch between two states, “white” and “opaque,” and each state is heritable through many cell generations. Each cell type has a distinct cellular and colony morphology and they differ in many other properties including mating, nutritional specialization, and interactions with the innate immune system. Previous genetic screens to gain insight into white-opaque switching have focused on certain classes of genes (for example transcriptional regulators or chromatin modifying enzymes). In this paper, we examined 172 deletion mutants covering a broad range of cell functions. We identified 28 deletion mutants with at least a fivefold effect on switching frequencies; these cover a wide variety of functions ranging from membrane sensors to kinases to proteins of unknown function. In agreement with previous reports, we found that components of the pheromone signaling cascade affect white-to-opaque switching; however, our results suggest that the major effect of Cek1 on white-opaque switching occurs through the cell wall damage response pathway. Most of the genes we identified have not been previously implicated in white-opaque switching and serve as entry points to understand new aspects of this morphological transition.
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11
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Wang L, Chen R, Weng Q, Lin S, Wang H, Li L, Fuchs BB, Tan X, Mylonakis E. SPT20 Regulates the Hog1-MAPK Pathway and Is Involved in Candida albicans Response to Hyperosmotic Stress. Front Microbiol 2020; 11:213. [PMID: 32153525 PMCID: PMC7047840 DOI: 10.3389/fmicb.2020.00213] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 01/30/2020] [Indexed: 11/22/2022] Open
Abstract
Candida albicans is the most common fungal pathogen and relies on the Hog1-MAPK pathway to resist osmotic stress posed by the environment or during host invasions. Here, we investigated the role of SPT20 in response to osmotic stress. Testing a C. albicans spt20Δ/Δ mutant, we found it was sensitive to osmotic stress. Using sequence alignment, we identified the conserved functional domains between CaSpt20 and ScSpt20. Reconstitution of the Spt20 function in a spt20Δ/CaSPT20 complemented strain found CaSPT20 can suppress the high sensitivity to hyperosmotic stressors, a cell wall stress agent, and antifungal drugs in the Saccharomyces cerevisiae spt20Δ/Δ mutant background. We measured the cellular glycerol accumulation and found it was significantly lower in the C. albicans spt20Δ/Δ mutant strain, compared to the wild type strain SC5314 (P < 0.001). This result was also supported by quantitative reverse transcription-PCR, which showed the expression levels of gene contributing to glycerol accumulation were reduced in Caspt20Δ/Δ compared to wild type (GPD2 and TGL1, P < 0.001), while ADH7 and AGP2, whose expression can lead to glycerol decrease, were induced when cells were exposed to high osmolarity (ADH7, P < 0.001; AGP2, P = 0.002). In addition, we tested the transcription levels of Hog1-dependent osmotic stress response genes, and found that they were significantly upregulated in wild type cells encountering hyperosmolarity, while the expression of HGT10, SKO1, CAT1, and SLP3 were not induced when SPT20 was deleted. Although the transcript of ORF19.3661 and ORF19.4370 in Caspt20Δ/Δ was induced in the presence of 1 M NaCl, the levels were less than what was observed in the wild type (ORF19.3661, P = 0.007; ORF19.4370, P = 0.011). Moreover, the deletion of CaSPT20 in C. albicans reduced phosphorylation levels of Hog1. These findings suggested that SPT20 is conserved between yeast and C. albicans and plays an important role in adapting to osmotic stress through regulating Hog1-MAPK pathway.
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Affiliation(s)
- Lianfang Wang
- Department of Respiratory and Critical Care Medicine, Chronic Airways Diseases Laboratory, Huiqiao Medical Center, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Ruilan Chen
- The Second Clinical College of Guangzhou University of Chinese Medicine, Guangzhou, China
- Department of Intensive Care Unit, Fangcun Branch of Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China
- Guangdong Provincial Academy of Chinese Medical Sciences, Guangzhou, China
| | - Qiuting Weng
- Department of Respiratory and Critical Care Medicine, Chronic Airways Diseases Laboratory, Huiqiao Medical Center, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Shaoming Lin
- Department of Respiratory, Longhua District People’s Hospital, Shenzhen, China
| | - Huijun Wang
- Department of Respiratory and Critical Care Medicine, Chronic Airways Diseases Laboratory, Huiqiao Medical Center, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Li Li
- Huiqiao Medical Center, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Beth Burgwyn Fuchs
- Department of Medicine, Division of Infectious Diseases, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, RI, United States
| | - Xiaojiang Tan
- Department of Respiratory and Critical Care Medicine, Chronic Airways Diseases Laboratory, Huiqiao Medical Center, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Eleftherios Mylonakis
- Department of Medicine, Division of Infectious Diseases, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, RI, United States
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12
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Das S, Bhuyan R, Bagchi A, Saha T. Network analysis of hyphae forming proteins in Candida albicans identifies important proteins responsible for pathovirulence in the organism. Heliyon 2019; 5:e01916. [PMID: 31338453 PMCID: PMC6580234 DOI: 10.1016/j.heliyon.2019.e01916] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 05/20/2019] [Accepted: 06/03/2019] [Indexed: 12/21/2022] Open
Abstract
Candida albicans causes two types of major infections in humans: superficial infections, such as skin and mucosal infection, and life-threatening systemic infections, like airway and catheter-related blood stream infections. It is a polymorphic fungus with two distinct forms (yeast and hyphal) and the morphological plasticity is strongly associated with many disease causing proteins. In this study, 137 hyphae associated proteins from Candida albicans (C. albicans) were collected from different sources to create a Protein-Protein Interaction (PPI) network. Out of these, we identified 18 hub proteins (Hog1, Hsp90, Cyr1, Cdc28, Pkc1, Cla4, Cdc42, Tpk1, Act1, Pbs2, Bem1, Tpk2, Ras1, Cdc24, Rim101, Cdc11, Cdc10 and Cln3) that were the most important ones in hyphae development. Ontology and functional enrichment analysis of these proteins could categorize these hyphae associated proteins into groups like signal transduction, kinase activity, biofilm formation, filamentous growth, MAPK signaling etc. Functional annotation analysis of these proteins showed that the protein kinase activity to be essential for hyphae formation in Candida. Additionally, most of the proteins from the network were predicted to be localized on cell surface or periphery, suggesting them as the main protagonists in inducing infections within the host. The complex hyphae formation phenomenon of C. albicans is an attractive target for exploitation to develop new antifungals and anti-virulence strategies to combat C. albicans infections. We further tried to characterize few of the most crucial proteins, especially the kinases by their sequence and structural prospects. Therefore, through this article an attempt to understand the hyphae forming protein network analysis has been made to unravel and elucidate the complex pathogenesis processes with the principal aim of systems biological research involving novel Bioinformatics strategies to combat fungal infections.
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Affiliation(s)
- Sanjib Das
- Department of Molecular Biology & Biotechnology, University of Kalyani, West Bengal, 741235, India
| | - Rajabrata Bhuyan
- Department of Biochemistry & Biophysics, University of Kalyani, West Bengal, 741235, India
| | - Angshuman Bagchi
- Department of Biochemistry & Biophysics, University of Kalyani, West Bengal, 741235, India
| | - Tanima Saha
- Department of Molecular Biology & Biotechnology, University of Kalyani, West Bengal, 741235, India
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González-Rubio G, Fernández-Acero T, Martín H, Molina M. Mitogen-Activated Protein Kinase Phosphatases (MKPs) in Fungal Signaling: Conservation, Function, and Regulation. Int J Mol Sci 2019; 20:ijms20071709. [PMID: 30959830 PMCID: PMC6479966 DOI: 10.3390/ijms20071709] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 04/01/2019] [Accepted: 04/03/2019] [Indexed: 12/16/2022] Open
Abstract
Mitogen-activated protein kinases (MAPKs) are key mediators of signaling in fungi, participating in the response to diverse stresses and in developmental processes. Since the precise regulation of MAPKs is fundamental for cell physiology, fungi bear dual specificity phosphatases (DUSPs) that act as MAP kinase phosphatases (MKPs). Whereas fungal MKPs share characteristic domains of this phosphatase subfamily, they also have specific interaction motifs and particular activation mechanisms, which, for example, allow some yeast MKPs, such as Saccharomyces cerevisiae Sdp1, to couple oxidative stress with substrate recognition. Model yeasts show that MKPs play a key role in the modulation of MAPK signaling flow. Mutants affected in S. cerevisiae Msg5 or in Schizosaccharomyces pombe Pmp1 display MAPK hyperactivation and specific phenotypes. MKPs from virulent fungi, such as Candida albicans Cpp1, Fusarium graminearum Msg5, and Pyricularia oryzae Pmp1, are relevant for pathogenicity. Apart from transcriptional regulation, MKPs can be post-transcriptionally regulated by RNA-binding proteins such as Rnc1, which stabilizes the S. pombePMP1 mRNA. P. oryzae Pmp1 activity and S. cerevisiae Msg5 stability are regulated by phosphorylation and ubiquitination, respectively. Therefore, fungi offer a platform to gain insight into the regulatory mechanisms that control MKPs.
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Affiliation(s)
- Gema González-Rubio
- Departamento de Microbiología y Parasitología. Facultad de Farmacia. Instituto Ramón y Cajal de Investigaciones Sanitarias (IRYCIS), Universidad Complutense de Madrid, Plaza de Ramón y Cajal s/n, 28040 Madrid, Spain.
| | - Teresa Fernández-Acero
- Departamento de Microbiología y Parasitología. Facultad de Farmacia. Instituto Ramón y Cajal de Investigaciones Sanitarias (IRYCIS), Universidad Complutense de Madrid, Plaza de Ramón y Cajal s/n, 28040 Madrid, Spain.
| | - Humberto Martín
- Departamento de Microbiología y Parasitología. Facultad de Farmacia. Instituto Ramón y Cajal de Investigaciones Sanitarias (IRYCIS), Universidad Complutense de Madrid, Plaza de Ramón y Cajal s/n, 28040 Madrid, Spain.
| | - María Molina
- Departamento de Microbiología y Parasitología. Facultad de Farmacia. Instituto Ramón y Cajal de Investigaciones Sanitarias (IRYCIS), Universidad Complutense de Madrid, Plaza de Ramón y Cajal s/n, 28040 Madrid, Spain.
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Abstract
MAP kinases and their regulators are critical components of eukaryotic signaling pathways implicated in normal cell behavior as well as abnormal behaviors linked to diseases such as cancer. The mating pathway of the yeast Saccharomyces cerevisiae was central in establishing the MAP kinase paradigm. Here we investigate the mating pathway in a different ascomycete, the fungal pathogen C. albicans. In this dimorphic fungus MAP kinases are also implicated in the mating response, with two MAP kinases apparently playing redundant roles in the mating process. This work establishes that while some level of mating can occur in the presence of a single kinase, the Cek1 kinase is most important for mating, while the Cek2 kinase is involved in adaptation to signaling. While both kinases appear to be themselves regulated by dephosphorylation through the action of the Cpp1 phosphatase, this process appears important for mating only in the case of Cek1. We investigated the relationships of the Cek1 and Cek2 mitogen-activated protein (MAP) kinases and the putative MAP kinase phosphatase Cpp1 in the mating process of Candida albicans. Mutants of the CPP1 gene are hyperresponsive to pheromone, generating large halos, high levels of projections, and an increase in pheromone-responsive gene expression. Mating-type-homozygous opaque cells that lack both kinases are sterile, consistent with previous observations, although several lines of evidence show that the two kinases do not simply provide redundant functions in the mating process. Loss of CEK1 reduces mating significantly, to about 0.3% of wild-type strains, and also reduces projection formation and pheromone-mediated gene expression. In contrast, loss of CEK2 has less of an effect, reducing mating to approximately one-third that of the wild-type strain and moderately reducing projection formation but having little influence on the induction of gene expression. However, loss of Cek2 function reduces adaptation to pheromone-mediated arrest. The mutation enhances pheromone response halos to a level similar to that of cpp1 mutants, although the cpp1 mutants are considerably more mating defective than the cek2 mutant. The double cek2 cpp1 mutant shows enhanced responsiveness relative to either single mutant in terms of gene expression and halo formation, suggesting the kinase and phosphatase roles in the adaptation process are independent. Analysis of protein phosphorylation shows that Cek1 undergoes pheromone-mediated phosphorylation of the activation loop, and this phosphorylation is enhanced in cells lacking either the Cpp1 phosphatase or the Cek2 kinase. In addition, Cek1-GFP shows enhanced nuclear localization in response to pheromone treatment. In contrast, Cek2 shows no evidence for pheromone-mediated phosphorylation or pheromone-mediated nuclear localization. Intriguingly, however, deletion of CPP1 enhances both the phosphorylation state and the nuclear localization of Cek2-GFP. Overall, these results identify a complex interaction among the MAP kinases and MAP kinase phosphatase that function in the C. albicans mating pathway. IMPORTANCE MAP kinases and their regulators are critical components of eukaryotic signaling pathways implicated in normal cell behavior as well as abnormal behaviors linked to diseases such as cancer. The mating pathway of the yeast Saccharomyces cerevisiae was central in establishing the MAP kinase paradigm. Here we investigate the mating pathway in a different ascomycete, the fungal pathogen C. albicans. In this dimorphic fungus MAP kinases are also implicated in the mating response, with two MAP kinases apparently playing redundant roles in the mating process. This work establishes that while some level of mating can occur in the presence of a single kinase, the Cek1 kinase is most important for mating, while the Cek2 kinase is involved in adaptation to signaling. While both kinases appear to be themselves regulated by dephosphorylation through the action of the Cpp1 phosphatase, this process appears important for mating only in the case of Cek1.
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