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Soll DR. White-opaque switching in Candida albicans: cell biology, regulation, and function. Microbiol Mol Biol Rev 2024; 88:e0004322. [PMID: 38546228 DOI: 10.1128/mmbr.00043-22] [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] [Indexed: 06/28/2024] Open
Abstract
SUMMARYCandida albicans remains a major fungal pathogen colonizing humans and opportunistically invading tissue when conditions are predisposing. Part of the success of C. albicans was attributed to its capacity to form hyphae that facilitate tissue invasion. However, in 1987, a second developmental program was discovered, the "white-opaque transition," a high-frequency reversible switching system that impacted most aspects of the physiology, cell architecture, virulence, and gene expression of C. albicans. For the 15 years following the discovery of white-opaque switching, its role in the biology of C. albicans remained elusive. Then in 2002, it was discovered that in order to mate, C. albicans had to switch from white to opaque, a unique step in a yeast mating program. In 2006, three laboratories simultaneously identified a putative master switch gene, which led to a major quest to elucidate the underlying mechanisms that regulate white-opaque switching. Here, the evolving discoveries related to this complicated phenotypic transition are reviewed in a quasi-chronological order not only to provide a historical perspective but also to highlight several unique characteristics of white-opaque switching, which are fascinating and may be important to the life history and virulence of this persistent pathogen. Many of these characteristics have not been fully investigated, in many cases, leaving intriguing questions unresolved. Some of these include the function of unique channeled pimples on the opaque cell wall, the capacity to form opaque cells in the absence of the master switch gene WOR1, the formation of separate "pathogenic" and "sexual" biofilms, and the possibility that a significant portion of natural strains colonizing the lower gastrointestinal tract may be in the opaque phase. This review addresses many of these characteristics with the intent of engendering interest in resolving questions that remain unanswered.
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Affiliation(s)
- David R Soll
- Department of Biology, University of Iowa, Iowa City, Iowa, USA
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2
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Luo Z, Xiong D, Tian C. The Roles of Gti1/Pac2 Family Proteins in Fungal Growth, Morphogenesis, Stress Response, and Pathogenicity. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2024; 37:488-497. [PMID: 38427716 DOI: 10.1094/mpmi-11-23-0198-cr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/03/2024]
Abstract
Gti1/Pac2 is a fungal-specific transcription factor family with a stable and conserved N-terminal domain. Generally, there are two members in this family, named Gti1/Wor1/Rpy1/Mit1/Reg1/Ros1/Sge1 and Pac2, which are involved in fungal growth, development, stress response, spore production, pathogenicity, and so on. The Gti1/Pac2 family proteins share some conserved and distinct functions. For example, in Schizosaccharomyces pombe, Gti1 promotes the initiation of gluconate uptake during glucose starvation, while Pac2 controls the onset of sexual development in a pathway independent of the cAMP cascade. In the last two decades, more attention was focused on the Gti1 and its orthologs because of their significant effect on morphological switching and fungal virulence. By contrast, limited work was published on the functions of Pac2, which is required for stress responses and conidiation, but plays a minor role in fungal virulence. In this review, we present an overview of our current understanding of the Gti1/Pac2 proteins that contribute to fungal development and/or pathogenicity and of the regulation mechanisms during infection related development. Understanding the working networks of the conserved Gti1/Pac2 transcription factors in fungal pathogenicity not only advances our knowledge of the highly elaborate infection process but may also lead to the development of novel strategies for the control of plant disease. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Zheng Luo
- State Key laboratory of Efficient Production of Forest Resources, Beijing Forestry University, Beijing 100083, China
- Beijing Key Laboratory for Forest Pest Control, Beijing Forestry University, Beijing 100083, China
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing 100083, China
| | - Dianguang Xiong
- State Key laboratory of Efficient Production of Forest Resources, Beijing Forestry University, Beijing 100083, China
- Beijing Key Laboratory for Forest Pest Control, Beijing Forestry University, Beijing 100083, China
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing 100083, China
| | - Chengming Tian
- State Key laboratory of Efficient Production of Forest Resources, Beijing Forestry University, Beijing 100083, China
- Beijing Key Laboratory for Forest Pest Control, Beijing Forestry University, Beijing 100083, China
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing 100083, China
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Román E, Prieto D, Hidalgo-Vico S, Alonso-Monge R, Pla J. The defective gut colonization of Candida albicans hog1 MAPK mutants is restored by overexpressing the transcriptional regulator of the white opaque transition WOR1. Virulence 2023; 14:2174294. [PMID: 36760104 PMCID: PMC9928469 DOI: 10.1080/21505594.2023.2174294] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023] Open
Abstract
The transcriptional master regulator of the white opaque transition of Candida albicans WOR1 is important for the adaptation to the commensal lifestyle in the mammalian gut, a major source of invasive candidiasis. We have generated cells that overproduce Wor1 in mutants defective in the Hog1 MAP kinase, defective in several stress responses and unable to colonize the mice gut. WOR1 overexpression allows hog1 to be established as a commensal in the murine gut in a commensalism model and even compete with wild-type C. albicans cells for establishment. This increased fitness correlates with an enhanced ability to adhere to biotic surfaces as well as increased proteinase and phospholipase production and a decrease in filamentation in vitro. We also show that hog1 WOR1OE are avirulent in a systemic candidiasis model in mice.
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Affiliation(s)
- Elvira Román
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain,CONTACT Elvira Román
| | - Daniel Prieto
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
| | - Susana Hidalgo-Vico
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
| | - Rebeca Alonso-Monge
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
| | - Jesús Pla
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain,Jesús Pla Parasitología Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
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Ke CL, Lew SQ, Hsieh Y, Chang SC, Lin CH. Convergent and divergent roles of the glucose-responsive kinase SNF4 in Candida tropicalis. Virulence 2023; 14:2175914. [PMID: 36745535 PMCID: PMC9928470 DOI: 10.1080/21505594.2023.2175914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The sucrose non-fermenting 1 (SNF1) complex is a heterotrimeric protein kinase complex that is an ortholog of the mammalian AMPK complex and is evolutionally conserved in most eukaryotes. This complex contains a catalytic subunit (Snf1), a regulatory subunit (Snf4) and a scaffolding subunit (Sip1/Sip2/Gal73) in budding yeast. Although the function of AMPK has been well studied in Saccharomyces cerevisiae and Candida albicans, the role of AMPK in Candida tropicalis has never been investigated. In this study, we focused on SNF4 in C. tropicalis as this fungus cannot produce a snf1Δ mutant. We demonstrated that C. tropicalis SNF4 shares similar roles in glucose derepression and is necessary for cell wall integrity and virulence. The expression of both SNF1 and SNF4 was significantly induced when glucose was limited. Furthermore, snf4Δ strains exhibited high sensitivity to many surface-perturbing agents because the strains contained lower levels of glucan, chitin and mannan. Interestingly, in contrast to C. albicans sak1Δ and snf4Δ, C. tropicalis snf4Δ exhibited phenotypes for cell aggregation and pseudohypha production. These data indicate that SNF4 performs convergent and divergent roles in C. tropicalis and possibly other unknown roles in the C. tropicalis SNF1-SNF4 AMPK pathway.
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Affiliation(s)
- Cai-Ling Ke
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Shi Qian Lew
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Yi Hsieh
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Szu-Cheng Chang
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Ching-Hsuan Lin
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, Taiwan,CONTACT Ching-Hsuan Lin
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5
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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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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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Das S, Goswami AM, Saha T. An insight into the role of protein kinases as virulent factors, regulating pathogenic attributes in Candida albicans. Microb Pathog 2022; 164:105418. [DOI: 10.1016/j.micpath.2022.105418] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 01/21/2022] [Accepted: 01/21/2022] [Indexed: 11/26/2022]
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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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Liu J, Li L, Wang Y, Yun X. Morphological and transcriptomic analysis of attenuated and virulent strains of Phytophthora infestans. Int Microbiol 2021; 25:89-98. [PMID: 34255222 DOI: 10.1007/s10123-021-00195-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 06/28/2021] [Accepted: 07/05/2021] [Indexed: 11/29/2022]
Abstract
Phytophthora infestans is a hemibiotroph Oomycete that primarily infects tomato. In this study, the growth status and pathogenicity of attenuated and virulent strains of Phytophthora infestans were determined. Furthermore, RNA-seq technology was used to explore the differences in gene transcription levels between attenuated and virulent strains. Gene Ontology (GO) classification and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed on the differentially expressed genes (DEGs) obtained by sequencing, and the significant DEGs related to the growth and pathogenicity of the strains were screened from the significantly enriched pathways. The results revealed that compared with the virulent strain, the growth of the attenuated strain was inhibited, the structure of hyphae was destroyed, and the disease index was decreased. The differences in the growth status and disease index of the attenuated strain were related to changes in several metabolic pathways, and the DEGs in the metabolic pathways indicated alterations in the attenuated strain growth and pathogenicity. There were 2,651 DEGs in the attenuated strain, of which 1,086 were upregulated and 1,565 were downregulated. The inhibited growth of the attenuated strain was associated with accumulation of excessive glucose, decomposition of serine/glycine, and reduction of tryptophan synthesis. The reduced pathogenicity of the strain was associated with degradation of the cell wall and reduced formation of melanin and α-keto butyric acid. These results could offer insights into the mechanisms of attenuation of Phytophthora infestans.
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Affiliation(s)
- Jiafang Liu
- College of Horticulture and Plant Protection, Inner Mongolia Agricultural University, No. 306 Zhaowuda Road, Hohhot, 010018, China
| | - Lei Li
- Manzhouli Russian Vocational and Technical College, Manzhouli College of Inner Mongolia University, Hulun Buir, 021400, China
| | - Yong Wang
- Inner Mongolia Academy of Agricultural and Animal Husbandry Sciences, Vegetable Research Institute, Hohhot, 010010, China
| | - Xingfu Yun
- College of Horticulture and Plant Protection, Inner Mongolia Agricultural University, No. 306 Zhaowuda Road, Hohhot, 010018, China.
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Ke CL, Liao YT, Lin CH. MSS2 maintains mitochondrial function and is required for chitosan resistance, invasive growth, biofilm formation and virulence in Candida albicans. Virulence 2021; 12:281-297. [PMID: 33427576 PMCID: PMC7808435 DOI: 10.1080/21505594.2020.1870082] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Candida albicans is the most prevalent fungal pathogen in humans, particularly in immunocompromised patients. In this study, by screening a C. albicans mutant library, we first identified that the MSS2 gene, an ortholog of Saccharomyces cerevisiae MSS2 required for mitochondrial respiration, mediates chitosan resistance. Upon treatment with 0.2% chitosan, the growth of mss2Δ strains was strikingly impaired, and MSS2 expression was significantly repressed by chitosan. Furthermore, mss2Δ strains exhibited slow growth on medium supplemented with glycerol as the sole carbon source. Similar to the chitosan-treated wild-type strain, the mss2Δ strain exhibited a significantly impaired ATP production ability. These data suggest that an antifungal mechanism of chitosan against C. albicans acts by inhibiting MSS2 gene expression, leading to repression of mitochondrial function. Normal respiratory function is suggested to be required for fungal virulence. Interestingly, the mss2Δ mutant strains exhibited significantly impaired invasive ability in vitro and ex vivo but retained normal hyphal development ability in liquid medium. Furthermore, the MSS2 deletion strains could not form robust biofilms and exhibited significantly reduced virulence. Collectively, these results demonstrated that the antifungal effect of chitosan against C. albicans is mediated via inhibition of mitochondrial biogenesis. These data may provide another strategy for antifungal drug development via inhibition of fungal mitochondria.
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Affiliation(s)
- Cai-Ling Ke
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University , Taipei, Taiwan
| | - Yu-Ting Liao
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University , Taipei, Taiwan
| | - Ching-Hsuan Lin
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University , Taipei, Taiwan
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Correia I, Wilson D, Hube B, Pla J. Characterization of a Candida albicans Mutant Defective in All MAPKs Highlights the Major Role of Hog1 in the MAPK Signaling Network. J Fungi (Basel) 2020; 6:jof6040230. [PMID: 33080787 PMCID: PMC7711971 DOI: 10.3390/jof6040230] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 10/12/2020] [Accepted: 10/14/2020] [Indexed: 12/16/2022] Open
Abstract
The success of Candida albicans as a pathogen relies on its ability to adapt and proliferate in different environmental niches. Pathways regulated by mitogen-activated protein kinases (MAPKs) are involved in sensing environmental conditions and developing an accurate adaptive response. Given the frequent cooperative roles of these routes in cellular functions, we have generated mutants defective in all combinations of the four described MAPKs in C. albicans and characterized its phenotype regarding sensitiveness to specific drugs, morphogenesis and interaction with host immune cells. We demonstrate that all MAPKs are dispensable in this yeast as a mutant defective in Cek1, Cek2, Mkc1 and Hog1 is viable although highly sensitive to oxidative and osmotic stress, displaying a specific pattern of sensitivity to antifungals. By comparing its phenotype with single, double and triple combinations of MAPK-deletion mutants we were able to unveil a Cek1-independent mechanism for Hog1 resistance to Congo red, and confirm the predominant effect of Hog1 on oxidative and osmotic adaptation. The quadruple mutant produces filaments under non-inducing conditions, but is unable to develop chlamydospores. Furthermore, cek1 cek2 mkc1 hog1 cells switch to the opaque state at high frequency, which is blocked by the ectopic expression of HOG1 suggesting a role of this kinase for phenotypic switching.
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Affiliation(s)
- Inês Correia
- iBiMED-Institute of Biomedicine, Department of Medical Sciences, University of Aveiro, Agra do Crasto, 3810-193 Aveiro, Portugal
- Correspondence: (I.C.); (J.P.); Tel.: +351-234-370-213 (I.C.); +34-913-941-617 (J.P.)
| | - Duncan Wilson
- Medical Research Council Centre for Medical Mycology, School of Biosciences, University of Exeter, Exeter EX4 4QD, UK;
| | - Bernhard Hube
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology-Hans-Knoell-Institute, Beutenbergstraße 11A, 07745 Jena, Germany;
- Institute of Microbiology, Friedrich Schiller University, Neugasse 25, 07743 Jena, Germany
| | - Jesús Pla
- Departamento de Microbiología y Parasitología-IRYCIS, Facultad de Farmacia, Universidad Complutense de Madrid, Avda. Ramón y Cajal s/n, 28040 Madrid, Spain
- Correspondence: (I.C.); (J.P.); Tel.: +351-234-370-213 (I.C.); +34-913-941-617 (J.P.)
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12
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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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Song YD, Hsu CC, Lew SQ, Lin CH. Candida tropicalis RON1 is required for hyphal formation, biofilm development, and virulence but is dispensable for N-acetylglucosamine catabolism. Med Mycol 2020; 59:379-391. [PMID: 32712662 DOI: 10.1093/mmy/myaa063] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 06/29/2020] [Accepted: 07/08/2020] [Indexed: 01/05/2023] Open
Abstract
NDT80-like family genes are highly conserved across a large group of fungi, but the functions of each Ndt80 protein are diverse and have evolved differently among yeasts and pathogens. The unique NDT80 gene in budding yeast is required for sexual reproduction, whereas three NDT80-like genes, namely, NDT80, REP1, and RON1, found in Candida albicans exhibit distinct functions. Notably, it was suggested that REP1, rather than RON1, is required for N-acetylglucosamine (GlcNAc) catabolism. Although Candida tropicalis, a widely dispersed fungal pathogen in tropical and subtropical areas, is closely related to Candida albicans, its phenotypic, pathogenic and environmental adaptation characteristics are remarkably divergent. In this study, we focused on the Ron1 transcription factor in C. tropicalis. Protein alignment showed that C. tropicalis Ron1 (CtRon1) shares 39.7% identity with C. albicans Ron1 (CaRon1). Compared to the wild-type strain, the C. tropicalis ron1Δ strains exhibited normal growth in different carbon sources and had similar expression levels of several GlcNAc catabolic genes during GlcNAc treatment. In contrast, C. tropicalis REP1 is responsible for GlcNAc catabolism and is involved in GlcNAc catabolic gene expressions, similar to C. albicans Rep1. However, REP1 deletion strains in C. tropicalis promote hyphal development in GlcNAc with low glucose content. Interestingly, CtRON1, but not CaRON1, deletion mutants exhibited significantly impaired hyphal growth and biofilm formation. As expected, CtRON1 was required for full virulence. Together, the results of this study showed divergent functions of CtRon1 compared to CaRon1; CtRon1 plays a key role in yeast-hyphal dimorphism, biofilm formation and virulence. LAY ABSTRACT In this study, we identified the role of RON1, an NDT80-like gene, in Candida tropicalis. Unlike the gene in Candida albicans, our studies showed that RON1 is a key regulator of hyphal formation, biofilm development and virulence but is dispensable for N-acetylglucosamine catabolism in C. tropicalis.
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Affiliation(s)
- Yu-De Song
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Chih-Chieh Hsu
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Shi Qian Lew
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Ching-Hsuan Lin
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, Taiwan
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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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15
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Yu Z, Ali A, Igbalajobi OA, Streng C, Leister K, Krauß N, Lamparter T, Fischer R. Two hybrid histidine kinases, TcsB and the phytochrome FphA, are involved in temperature sensing in
Aspergillus nidulans. Mol Microbiol 2019; 112:1814-1830. [DOI: 10.1111/mmi.14395] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/22/2019] [Indexed: 12/30/2022]
Affiliation(s)
- Zhenzhong Yu
- Institute for Applied Biosciences Department of Microbiology Karlsruhe Institute of Technology (KIT) ‐ South Campus Fritz‐Haber‐Weg 4 Karlsruhe D‐76131Germany
- Jiangsu Provincial Key Laboratory of Organic Solid Waste Utilization College of Resources and Environmental Sciences Nanjing Agricultural University Nanjing 210095China
| | - Arin Ali
- Institute for Applied Biosciences Department of Microbiology Karlsruhe Institute of Technology (KIT) ‐ South Campus Fritz‐Haber‐Weg 4 Karlsruhe D‐76131Germany
| | - Olumuyiwa Ayokunle Igbalajobi
- Institute for Applied Biosciences Department of Microbiology Karlsruhe Institute of Technology (KIT) ‐ South Campus Fritz‐Haber‐Weg 4 Karlsruhe D‐76131Germany
| | - Christian Streng
- Institute for Applied Biosciences Department of Microbiology Karlsruhe Institute of Technology (KIT) ‐ South Campus Fritz‐Haber‐Weg 4 Karlsruhe D‐76131Germany
| | - Kai Leister
- Institute for Applied Biosciences Department of Microbiology Karlsruhe Institute of Technology (KIT) ‐ South Campus Fritz‐Haber‐Weg 4 Karlsruhe D‐76131Germany
| | - Norbert Krauß
- Botanical Institute Karlsruhe Institute of Technology (KIT) ‐ South Campus Karlsruhe D‐76131Germany
| | - Tilman Lamparter
- Botanical Institute Karlsruhe Institute of Technology (KIT) ‐ South Campus Karlsruhe D‐76131Germany
| | - Reinhard Fischer
- Institute for Applied Biosciences Department of Microbiology Karlsruhe Institute of Technology (KIT) ‐ South Campus Fritz‐Haber‐Weg 4 Karlsruhe D‐76131Germany
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16
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Day AM, Quinn J. Stress-Activated Protein Kinases in Human Fungal Pathogens. Front Cell Infect Microbiol 2019; 9:261. [PMID: 31380304 PMCID: PMC6652806 DOI: 10.3389/fcimb.2019.00261] [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: 05/09/2019] [Accepted: 07/04/2019] [Indexed: 11/28/2022] Open
Abstract
The ability of fungal pathogens to survive hostile environments within the host depends on rapid and robust stress responses. Stress-activated protein kinase (SAPK) pathways are conserved MAPK signaling modules that promote stress adaptation in all eukaryotic cells, including pathogenic fungi. Activation of the SAPK occurs via the dual phosphorylation of conserved threonine and tyrosine residues within a TGY motif located in the catalytic domain. This induces the activation and nuclear accumulation of the kinase and the phosphorylation of diverse substrates, thus eliciting appropriate cellular responses. The Hog1 SAPK has been extensively characterized in the model yeast Saccharomyces cerevisiae. Here, we use this a platform from which to compare SAPK signaling mechanisms in three major fungal pathogens of humans, Candida albicans, Aspergillus fumigatus, and Cryptococcus neoformans. Despite the conservation of SAPK pathways within these pathogenic fungi, evidence is emerging that their role and regulation has significantly diverged. However, consistent with stress adaptation being a common virulence trait, SAPK pathways are important pathogenicity determinants in all these major human pathogens. Thus, the development of drugs which target fungal SAPKs has the exciting potential to generate broad-acting antifungal treatments.
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Affiliation(s)
- Alison M Day
- Faculty of Medicine, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle Upon Tyne, United Kingdom
| | - Janet Quinn
- Faculty of Medicine, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle Upon Tyne, United Kingdom
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17
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Chien CT, Chen YC, Liu YC, Liang SH, Lin HH, Lin CH. The antimicrobial photodynamic inactivation resistance of Candida albicans is modulated by the Hog1 pathway and the Cap1 transcription factor. Med Mycol 2019; 57:618-627. [PMID: 30289464 DOI: 10.1093/mmy/myy079] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 08/02/2018] [Accepted: 09/23/2018] [Indexed: 12/22/2022] Open
Abstract
Candida albicans is the most important fungal pathogen afflicting humans, particularly immunocompromised patients. However, currently available antifungal drugs are limited and ineffective against drug-resistant strains. The development of new drugs or alternative therapeutic approaches to control fungal infections is urgent and necessary. Photodynamic inactivation (PDI) is a new promising therapy for eradicating microorganism infections through combining visible light, photosensitizers, and oxygen to generate reactive oxygen species (ROS). Although cytoprotective responses induced by photodynamic therapy (PDT) have been well studied in cancer cells, the mechanisms by which C. albicans responds to PDI are largely unknown. In this study, we first demonstrated that PDI induces C. albicans Hog1p activation. Deletion of any of the SSK2, PBS2, and HOG1 genes significantly decreased the survival rate after photochemical reactions, indicating that the Hog1 SAPK pathway is required for tolerance to PDI. Furthermore, the basic leucine zipper transcription factor Cap1 that regulates several downstream antioxidant genes was highly expressed during the response to PDI, and loss of CAP1 also resulted in decreased C. albicans survival rates. This study demonstrates the importance of the Hog1 SAPK and the Cap1 transcription factor, which regulates in resistance to PDI-mediated oxidative stress in C. albicans. Understanding the mechanisms by which C. albicans responds to PDI and consequently scavenges ROS will be very useful for the further development of therapeutics to control fungal infectious diseases, particularly those of the skin and mucosal infections.
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Affiliation(s)
- Chih-Ting Chien
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Yu-Chia Chen
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Yun-Chun Liu
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, Taiwan
| | | | - Hsien-Hen Lin
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Ching-Hsuan Lin
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, Taiwan
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18
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Shih PY, Liao YT, Tseng YK, Deng FS, Lin CH. A Potential Antifungal Effect of Chitosan Against Candida albicans Is Mediated via the Inhibition of SAGA Complex Component Expression and the Subsequent Alteration of Cell Surface Integrity. Front Microbiol 2019; 10:602. [PMID: 30972050 PMCID: PMC6443709 DOI: 10.3389/fmicb.2019.00602] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 03/11/2019] [Indexed: 12/21/2022] Open
Abstract
Due to the high incidence of nosocomial Candida albicans infection, the first-line drugs for C. albicans infection have been heavily used, and the emergence of drug-resistant strains has gradually increased. Thus, a new antifungal drug or therapeutic method is needed. Chitosan, a product of chitin deacetylation, is considered to be potentially therapeutic for fungal infections because of its excellent biocompatibility, biodegradability and low toxicity. The biocidal action of chitosan against C. albicans shows great commercial potential, but the exact mechanisms underlying its antimicrobial activity are unclear. To reveal these mechanisms, mutant library screening was performed. ADA2 gene, which encodes a histone acetylation coactivator in the SAGA complex, was identified. Transmission electronic microscopy images showed that the surface of chitosan-treated ada2Δ cells was substantially disrupted and displayed an irregular morphology. Interestingly, the cell wall of ada2Δ cells was significantly thinner than that of wild-type cells, with a thickness similar to that seen in the chitosan-treated wild-type strain. Although ADA2 is required for chitosan tolerance, expression of ADA2 and several Ada2-mediated cell wall-related genes (ALS2, PGA45, and ACE2) and efflux transporter genes (MDR1 and CDR1) were significantly inhibited by chitosan. Furthermore, GCN5 encoding a SAGA complex catalytic subunit was inhibited by chitosan, and gcn5Δ cells exhibited phenotypes comparable to those of ada2Δ cells in response to chitosan and other cell surface-disrupting agents. This study demonstrated that a potential antifungal mechanism of chitosan against C. albicans operates by inhibiting SAGA complex gene expression, which decreases the protection of the cell surface against chitosan.
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Affiliation(s)
- Pei-Yu Shih
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Yu-Ting Liao
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Yi-Kai Tseng
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Fu-Sheng Deng
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Ching-Hsuan Lin
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, Taiwan
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19
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Román E, Correia I, Prieto D, Alonso R, Pla J. The HOG MAPK pathway in Candida albicans: more than an osmosensing pathway. Int Microbiol 2019; 23:23-29. [DOI: 10.1007/s10123-019-00069-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 02/21/2019] [Accepted: 02/27/2019] [Indexed: 12/18/2022]
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20
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Deng FS, Lin CH. Cpp1 phosphatase mediated signaling crosstalk between Hog1 and Cek1 mitogen-activated protein kinases is involved in the phenotypic transition in Candida albicans. Med Mycol 2018; 56:242-252. [PMID: 28431022 DOI: 10.1093/mmy/myx027] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 03/23/2017] [Indexed: 12/29/2022] Open
Abstract
Cellular signaling pathways involved in cell growth and differentiation mediated by mitogen-activated protein kinase (MAPK) cascades have been well characterized in fungi. However, the mechanisms of signaling crosstalk between MAPKs to ensure signaling specificity are largely unknown. Previous work showed that activation of the Candida albicans Cek1 MAPK pathway resulted in opaque cell formation and filamentation, which mirrored the phenotypes to hog1Δ. Additionally, deleting the HOG1 gene stimulated Cek1p. Thus, we hypothesized that an unknown factor could act as a bridge between these two MAPKs. In Saccharomyces cerevisiae, the dual-specificity phosphatase (DSP) Msg5 specifically dephosphorylates Fus3p/Kss1p. C. albicans Cpp1, an ortholog of Msg5, has been shown to be important in regulating Cek1p. Compared with the wild-type strain, hog1Δ shows a ∼40% reduction in CPP1 expression. Consistent with previous reports, CPP1 deletion also resulted in Cek1 hyperphosphorylation, implicating Cpp1 as a regulator of the Hog1 and Cek1 cascades. Interestingly, both cpp1Δ and hog1Δ induced 100% opaque colony formation in MTL-homozygous strains grown on N-acetylglucosamine (NAG) plates, whereas the wild-type and complemented strains exhibited 80.9% and 77.1% white-to-opaque switching rates, respectively. CPP1 gene deletion also caused hyperfilamentous phenotypes in both white and opaque cells. These phenomena may be due to highly phosphorylated Cek1p, as deleting CEK1 in the cpp1Δ background generated nonfilamentous strains and reduced opaque colony formation. Taken together, we conclude that cpp1Δ and hog1Δ exhibited comparable phenotypes, and both are involved in regulating Cek1 phosphorylation, implicating Cpp1 phosphatase as a key intermediary between the Hog1 and Cek1 signal transduction pathways.
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Affiliation(s)
- Fu-Sheng Deng
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Ching-Hsuan Lin
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, Taiwan
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21
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Day AM, McNiff MM, da Silva Dantas A, Gow NAR, Quinn J. Hog1 Regulates Stress Tolerance and Virulence in the Emerging Fungal Pathogen Candida auris. mSphere 2018; 3:e00506-18. [PMID: 30355673 PMCID: PMC6200985 DOI: 10.1128/msphere.00506-18] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 09/18/2018] [Indexed: 01/14/2023] Open
Abstract
Candida auris has recently emerged as an important, multidrug-resistant fungal pathogen of humans. Comparative studies indicate that despite high levels of genetic divergence, C. auris is as virulent as the most pathogenic member of the genus, Candida albicans However, key virulence attributes of C. albicans, such as morphogenetic switching, are not utilized by C. auris, indicating that this emerging pathogen employs alternative strategies to infect and colonize the host. An important trait required for the pathogenicity of many fungal pathogens is the ability to adapt to host-imposed stresses encountered during infection. Here, we investigated the relative resistance of C. auris and other pathogenic Candida species to physiologically relevant stresses and explored the role of the evolutionarily conserved Hog1 stress-activated protein kinase (SAPK) in promoting stress resistance and virulence. In comparison to C. albicans, C. auris is relatively resistant to hydrogen peroxide, cationic stress, and cell-wall-damaging agents. However, in contrast to other Candida species examined, C. auris was unable to grow in an anaerobic environment and was acutely sensitive to organic oxidative-stress-inducing agents. An analysis of C. aurishog1Δ cells revealed multiple roles for this SAPK in stress resistance, cell morphology, aggregation, and virulence. These data demonstrate that C. auris has a unique stress resistance profile compared to those of other pathogenic Candida species and that the Hog1 SAPK has pleiotropic roles that promote the virulence of this emerging pathogen.IMPORTANCE The rapid global emergence and resistance of Candidaauris to current antifungal drugs highlight the importance of understanding the virulence traits exploited by this human fungal pathogen to cause disease. Here, we characterize the stress resistance profile of C. auris and the role of the Hog1 stress-activated protein kinase (SAPK) in stress resistance and virulence. Our findings that C. auris is acutely sensitive to certain stresses may facilitate control measures to prevent persistent colonization in hospital settings. Furthermore, our observation that the Hog1 SAPK promotes C. auris virulence akin to that reported for many other pathogenic fungi indicates that antifungals targeting Hog1 signaling would be broad acting and effective, even on emerging drug-resistant pathogens.
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Affiliation(s)
- Alison M Day
- Institute for Cell and Molecular Biosciences, Faculty of Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Megan M McNiff
- Institute for Cell and Molecular Biosciences, Faculty of Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Alessandra da Silva Dantas
- MRC Centre for Medical Mycology, Institute of Medical Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Neil A R Gow
- MRC Centre for Medical Mycology, Institute of Medical Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Janet Quinn
- Institute for Cell and Molecular Biosciences, Faculty of Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
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22
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Deng FS, Lin CH. Identification and characterization of ORF19.1725, a novel gene contributing to the white cell pheromone response and virulence-associated functions in Candida albicans. Virulence 2018; 9:866-878. [PMID: 29726301 PMCID: PMC5955465 DOI: 10.1080/21505594.2018.1456228] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
An epigenetic transition between white cells and opaque cells influences several properties of Candida albicans biology, including cellular morphology, biofilm formation, virulence, and sexual mating. In particular, these two cell types exhibit marked differences in their ability to undergo sex. A previous study identified the transcriptional regulator of pheromone response in both the white and opaque states as Cph1 because deletion of this gene abolished both pheromone-induced cell adhesion in white cells and sexual mating in opaque cells. To further explore how these cell types exhibit distinct biological outputs upon pheromone stimulation, we selected five Cph1-regulated genes with significant expression during the pheromone response in the white state but not the opaque state. These phase-specific pheromone-induced genes are ORF19.1539, ORF19.1725, ORF19.2430, ORF19.2691 and ORF19.5557. Deletion of each gene revealed that orf19.1539Δ, orf19.1725Δ, orf19.2430Δ and orf19.5557Δ showed significant decreases in pheromone-stimulated cell adhesion in the white state but retained normal mating competency in the opaque state, indicating that a particular role in white cell pheromone response is mediated by these four genes. Interestingly, the defects of orf19.1725Δ in pheromone-stimulated cell adhesion also abolished conventional biofilms and hyphal growth. Zebrafish egg infection assays further demonstrated that ORF19.1725 is involved in cell adhesion, penetration and virulence. Overall, four Cph1-regulated downstream targets were identified in the regulation of white cell pheromone response. We also clarified the roles of C. albicans ORF19.1725 in cell adhesion, hyphal growth, biofilm formation and virulence.
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Affiliation(s)
- Fu-Sheng Deng
- a Department of Biochemical Science and Technology , College of Life Science, National Taiwan University , Taipei , Taiwan
| | - Ching-Hsuan Lin
- a Department of Biochemical Science and Technology , College of Life Science, National Taiwan University , Taipei , Taiwan
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23
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Carapia-Minero N, Castelán-Vega JA, Pérez NO, Rodríguez-Tovar AV. The phosphorelay signal transduction system in Candida glabrata: an in silico analysis. J Mol Model 2017; 24:13. [PMID: 29248994 DOI: 10.1007/s00894-017-3545-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 11/24/2017] [Indexed: 01/18/2023]
Abstract
Signaling systems allow microorganisms to sense and respond to different stimuli through the modification of gene expression. The phosphorelay signal transduction system in eukaryotes involves three proteins: a sensor protein, an intermediate protein and a response regulator, and requires the transfer of a phosphate group between two histidine-aspartic residues. The SLN1-YPD1-SSK1 system enables yeast to adapt to hyperosmotic stress through the activation of the HOG1-MAPK pathway. The genetic sequences available from Saccharomyces cerevisiae were used to identify orthologous sequences in Candida glabrata, and putative genes were identified and characterized by in silico assays. An interactome analysis was carried out with the complete genome of C. glabrata and the putative proteins of the phosphorelay signal transduction system. Next, we modeled the complex formed between the sensor protein CgSln1p and the intermediate CgYpd1p. Finally, phosphate transfer was examined by a molecular dynamic assay. Our in silico analysis showed that the putative proteins of the C. glabrata phosphorelay signal transduction system present the functional domains of histidine kinase, a downstream response regulator protein, and an intermediate histidine phosphotransfer protein. All the sequences are phylogenetically more related to S. cerevisiae than to C. albicans. The interactome suggests that the C. glabrata phosphorelay signal transduction system interacts with different proteins that regulate cell wall biosynthesis and responds to oxidative and osmotic stress the same way as similar systems in S. cerevisiae and C. albicans. Molecular dynamics simulations showed complex formation between the response regulator domain of histidine kinase CgSln1 and intermediate protein CgYpd1 in the presence of a phosphate group and interactions between the aspartic residue and the histidine residue. Overall, our research showed that C. glabrata harbors a functional SLN1-YPD1-SSK1 phosphorelay system.
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Affiliation(s)
- Natalee Carapia-Minero
- Laboratorio de Micología Médica, Depto. de Microbiología, Escuela Nacional de Ciencias Biológicas (ENCB) , Instituto Politécnico Nacional, Prolongación de Carpio y Plan de Ayala s/n, Col. Casco de Santo Tomás, Del. Miguel Hidalgo, CP 11340, Ciudad de México, Mexico
| | - Juan Arturo Castelán-Vega
- Laboratorio de Producción y Control de Biológicos ENCB, Instituto Politécnico Nacional, Carpio y Plan de Ayala s/n, Col. Casco de Santo Tomás, Del. Miguel Hidalgo, CP 11340, Ciudad de México, Mexico
| | - Néstor Octavio Pérez
- Unidad de investigación y Desarrollo, Probiomed, SA de CV, Cruce de Carreteras Acatzingo-Zumpahuacan S/N, CP 52400, Tenancingo, Edo de México, Mexico.
| | - Aída Verónica Rodríguez-Tovar
- Laboratorio de Micología Médica, Depto. de Microbiología, Escuela Nacional de Ciencias Biológicas (ENCB) , Instituto Politécnico Nacional, Prolongación de Carpio y Plan de Ayala s/n, Col. Casco de Santo Tomás, Del. Miguel Hidalgo, CP 11340, Ciudad de México, Mexico.
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24
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Li HM, Shimizu-Imanishi Y, Tanaka R, Li RY, Yaguchi T. White-opaque Switching in Different Mating Type-like Locus Gene Types of Clinical Candida albicans Isolates. Chin Med J (Engl) 2016; 129:2725-2732. [PMID: 27824006 PMCID: PMC5126165 DOI: 10.4103/0366-6999.193442] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
BACKGROUND Candida albicans (C. albicans) can become a pathogen causing superficial as well as life-threatening systemic infections, especially in immunocompromised patients. Many phenotypic attributes contribute to its capacity to colonize human organs. In our study, 93 C. albicans isolates from patients of various candidiasis in a hospital of China were surveyed. We aimed to investigate the white-opaque (WO) switching competence, drug sensitivity, and virulence of mating type-like (MTL) a/α isolates. METHODS Internal transcribed spacer (ITS) gene and the MTL configuration were detected in all the isolates by reverse transcription-polymerase chain reaction. White/opaque phenotype and doubling time of cell growth were determined. The minimum inhibitory concentrations of antifungal agent were measured using broth microdilution method. RESULTS Sixty-four isolates (69.6%) were classified to serotype A, 19 (20.6%) to serotype B, and 9 (9.8%) to serotype C. Moreover, phylogenetic analysis showed that these isolates were divided into four different subgroups of ITS genotypes. Most of our clinical isolates were MTL a/α type, while 6.8% remained MTL a or MTLα type. The frequency of opaque phenotype was 71.0% (66 isolates). Following the guidelines of Clinical and Laboratory Standards Institute M27-A3, all isolates were susceptible to caspofungin and a few (0.6-3.2%) of them showed resistance against amphotericin B, flucytosine, fluconazole, itraconazole, and voriconazole. CONCLUSIONS From these analyses, there were comparatively more C. albicans strains classified into serotype B, and the frequency of opaque phase strains was significant in the clinical isolates from China. Genetic, phenotypic, or drug susceptibility patterns were not significantly different from previous studies. MTL a/α isolates could also undergo WO switching which facilitates their survival.
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Affiliation(s)
- Hou-Min Li
- Department of Dermatology, Peking University People's Hospital, Beijing 100044, China
| | | | - Reiko Tanaka
- Medical Mycology Research Center, Chiba University, Chiba 260-8673, Japan, japan
| | - Ruo-Yu Li
- Department of Dermatology, Peking University First Hospital, Beijing 100034, China
| | - Takashi Yaguchi
- Medical Mycology Research Center, Chiba University, Chiba 260-8673, Japan, japan
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25
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Yan M, Dai W, Cai E, Deng YZ, Chang C, Jiang Z, Zhang LH. Transcriptome analysis of Sporisorium scitamineum reveals critical environmental signals for fungal sexual mating and filamentous growth. BMC Genomics 2016; 17:354. [PMID: 27185248 PMCID: PMC4867532 DOI: 10.1186/s12864-016-2691-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 05/05/2016] [Indexed: 11/10/2022] Open
Abstract
Background Sporisorium scitamineum causes the sugarcane smut disease, one of the most serious constraints to global sugarcane production. S. scitamineum possesses a sexual mating system composed of two mating-type loci, a and b locus. We previously identified and deleted the b locus in S. scitamineum, and found that the resultant SsΔMAT-1b mutant was defective in mating and pathogenicity. Results To further understand the function of b-mating locus, we carried out transcriptome analysis by comparing the transcripts of the mutant strain SsΔMAT-1b, from which the SsbE1 and SsbW1 homeodomain transcription factors have previously been deleted, with those from the wild-type MAT-1 strain. Also the transcripts from SsΔMAT-1b X MAT-2 were compared with those from wild-type MAT-1 X MAT-2 mating. A total of 209 genes were up-regulated (p < 0.05) in the SsΔMAT-1b mutant, compared to the wild-type MAT-1 strain, while 148 genes down-regulated (p < 0.05). In the mixture, 120 genes were up-regulated (p < 0.05) in SsΔMAT-1b X MAT-2, which failed to mate, compared to the wild-type MAT-1 X MAT-2 mating, and 271 genes down-regulated (p < 0.05). By comparing the up- and down-regulated genes in these two sets, it was found that 15 up-regulated and 37 down-regulated genes were common in non-mating haploid and mating mixture, which indeed could be genes regulated by b-locus. Furthermore, GO and KEGG enrichment analysis suggested that carbon metabolism pathway and stress response mediated by Hog1 MAPK signaling pathway were altered in the non-mating sets. Conclusions Experimental validation results indicate that the bE/bW heterodimeric transcriptional factor, encoded by the b-locus, could regulate S. scitamineum sexual mating and/or filamentous growth via modulating glucose metabolism and Hog1-mediating oxidative response. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2691-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Meixin Yan
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Agriculture, South China Agricultural University, Guangzhou, Peoples' Republic of China.,Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, Peoples' Republic of China
| | - Weijun Dai
- Guangdong Innovative and Entepreneurial Research Team of Sociomicrobiology Basic Science and Frontier Technology, South China Agricultural University, Guangzhou, Peoples' Republic of China.,Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, Peoples' Republic of China
| | - Enping Cai
- Guangdong Innovative and Entepreneurial Research Team of Sociomicrobiology Basic Science and Frontier Technology, South China Agricultural University, Guangzhou, Peoples' Republic of China.,Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, Peoples' Republic of China
| | - Yi Zhen Deng
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Agriculture, South China Agricultural University, Guangzhou, Peoples' Republic of China.,Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, Peoples' Republic of China
| | - Changqing Chang
- Guangdong Innovative and Entepreneurial Research Team of Sociomicrobiology Basic Science and Frontier Technology, South China Agricultural University, Guangzhou, Peoples' Republic of China.,Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, Peoples' Republic of China
| | - Zide Jiang
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Agriculture, South China Agricultural University, Guangzhou, Peoples' Republic of China.
| | - Lian-Hui Zhang
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Agriculture, South China Agricultural University, Guangzhou, Peoples' Republic of China. .,Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, Peoples' Republic of China.
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26
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Chang WH, Liang SH, Deng FS, Lin CH. The conserved dual phosphorylation sites of the Candida albicans Hog1 protein are crucial for white-opaque switching, mating, and pheromone-stimulated cell adhesion. Med Mycol 2016; 54:628-40. [PMID: 27118797 DOI: 10.1093/mmy/myw015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 02/24/2016] [Indexed: 01/13/2023] Open
Abstract
Candida albicans is an opportunistic human pathogen capable of causing life-threatening infections in immunocompromised patients. C. albicans has a unique morphological transition between white and opaque phases. These two cells differ in virulence, mating capability, biofilm formation, and host-cell interaction. Previous studies revealed that deletion of the SSK2, PBS2, or HOG1 gene resulted in 100% opaque cell formation and suppressed the mating response. Thr-174 and Tyr-176 of the Hog1 protein are important phosphoacceptors and can be activated in response to stimuli. In this study, we first demonstrated the importance of two conserved phosphorylation sites in white-opaque switching, mating, and pheromone-stimulated cell adhesion. Six Hog1 point-mutated strains were generated, including nonphosphorylated strains (Hog1(T174A), Hog1(Y176F), and Hog1(T174A,Y176F)) and negatively charged phosphorylated strains (Hog1(T174D), Hog1(Y176D), and Hog1(T174D,Y176D)). Point mutation on Thr-174, Tyr-176 or in combination with the Hog1 protein in C. albicans MTL homozygous strains stimulated opaque cell formation at a frequency of 100%. Furthermore, mating projections of point-mutated strains were significantly shorter and their mating efficiencies and pheromone-stimulated cell adhesive numbers were lower than those of the wild-type. By investigating the effects of Hog1 phosphorylation in ssk1Δ and sln1Δ, we also demonstrate that the phosphorylation intensity of Hog1p is directly involved in the white-opaque switching. Taken together, the results of our study demonstrate that dual phosphorylation sites of C. albicans are crucial for white-opaque transition, sexual mating, and pheromone-induced cell adhesion.
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Affiliation(s)
- Wen-Han Chang
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Shen-Huan Liang
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Fu-Sheng Deng
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Ching-Hsuan Lin
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, Taiwan
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27
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Bruder Nascimento ACMDO, Dos Reis TF, de Castro PA, Hori JI, Bom VLP, de Assis LJ, Ramalho LNZ, Rocha MC, Malavazi I, Brown NA, Valiante V, Brakhage AA, Hagiwara D, Goldman GH. Mitogen activated protein kinases SakA(HOG1) and MpkC collaborate for Aspergillus fumigatus virulence. Mol Microbiol 2016; 100:841-59. [PMID: 26878695 DOI: 10.1111/mmi.13354] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/11/2016] [Indexed: 01/24/2023]
Abstract
Here, we investigated which stress responses were influenced by the MpkC and SakA mitogen-activated protein kinases of the high-osmolarity glycerol (HOG) pathway in the fungal pathogen Aspergillus fumigatus. The ΔsakA and the double ΔmpkC ΔsakA mutants were more sensitive to osmotic and oxidative stresses, and to cell wall damaging agents. Both MpkC::GFP and SakA::GFP translocated to the nucleus upon osmotic stress and cell wall damage, with SakA::GFP showing a quicker response. The phosphorylation state of MpkA was determined post exposure to high concentrations of congo red and Sorbitol. In the wild-type strain, MpkA phosphorylation levels progressively increased in both treatments. In contrast, the ΔsakA mutant had reduced MpkA phosphorylation, and surprisingly, the double ΔmpkC ΔsakA had no detectable MpkA phosphorylation. A. fumigatus ΔsakA and ΔmpkC were virulent in mouse survival experiments, but they had a 40% reduction in fungal burden. In contrast, the ΔmpkC ΔsakA double mutant showed highly attenuated virulence, with approximately 50% mice surviving and a 75% reduction in fungal burden. We propose that both cell wall integrity (CWI) and HOG pathways collaborate, and that MpkC could act by modulating SakA activity upon exposure to several types of stresses and during CW biosynthesis.
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Affiliation(s)
| | - Thaila Fernanda Dos Reis
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Patrícia Alves de Castro
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Juliana I Hori
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Vinícius Leite Pedro Bom
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Leandro José de Assis
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | | | - Marina Campos Rocha
- Departamento de Genética e Evolução, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, São Carlos, São Paulo, Brazil
| | - Iran Malavazi
- Departamento de Genética e Evolução, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, São Carlos, São Paulo, Brazil
| | - Neil Andrew Brown
- Plant Science and Crop Biology, Rothamsted Research, Harpenden, Hertfordshire, UK
| | - Vito Valiante
- Leibniz Junior Research Group Biobricks of Microbial Natural Product Syntheses, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute, Jena, Germany
| | - Axel A Brakhage
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Jena, Germany; Institute for Microbiology, Friedrich Schiller University, Jena, Germany
| | - Daisuke Hagiwara
- Medical Mycology Research Center, Chiba University, Chiba, Japan
| | - Gustavo H Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
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28
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Scaduto CM, Bennett RJ. Candida albicans the chameleon: transitions and interactions between multiple phenotypic states confer phenotypic plasticity. Curr Opin Microbiol 2015; 26:102-8. [PMID: 26189047 DOI: 10.1016/j.mib.2015.06.016] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2015] [Revised: 06/12/2015] [Accepted: 06/30/2015] [Indexed: 11/29/2022]
Abstract
The ability of microbial cells to exist in multiple states is a ubiquitous property that promotes adaptation and survival. This phenomenon has been extensively studied in the opportunistic pathogen Candida albicans, which can transition between multiple phenotypic states in response to environmental signals. C. albicans normally exists as a commensal in the human body, but can also cause debilitating mucosal infections or life-threatening systemic infections. The ability to switch between cellular forms contributes to C. albicans' capacity to infect different host niches, and strictly regulates the program of sexual mating. We review the unique properties associated with different phenotypic states, as well as how interactions between cells in different states can further augment microbial behavior.
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Affiliation(s)
| | - Richard J Bennett
- Brown University, 171 Meeting St, Providence, RI 02912, United States.
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