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Li Z, Huang Y, Tu J, Yang W, Liu N, Wang W, Sheng C. Discovery of BRD4-HDAC Dual Inhibitors with Improved Fungal Selectivity and Potent Synergistic Antifungal Activity against Fluconazole-Resistant Candida albicans. J Med Chem 2023; 66:5950-5964. [PMID: 37037787 DOI: 10.1021/acs.jmedchem.3c00165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
Abstract
Over the past several decades, invasive fungal infections, especially candidiasis, have caused dramatic morbidity and mortality due to ineffective antifungal drugs and severe drug resistance. Herein, new BRD4-histone deacetylase (HDAC) inhibitors were designed to restore the susceptibility of Candida albicans (C. albicans) to fluconazole (FLC). Interestingly, several compounds showed excellent selectivity against fungal HDACs. In particular, compound B2 showed excellent synergistic effect with FLC against resistant C. albicans (FICI = 0.063) with high selectivity against fungal HDACs (SI = 1653) and low cytotoxicity. Compound B2 effectively synergized with FLC and prevented biofilm formation and morphological transition in resistant C. albicans, potentiating the antifungal activity of FLC in vivo and significantly reducing kidney fungal loads. Thus, this drug combination is promising in the treatment of resistant C. albicans infections.
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Affiliation(s)
- Zhuang Li
- State Key Laboratory of Bioengineering Reactor, and Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science & Technology, 130 Meilong Road, Shanghai 200237, China
| | - Yahui Huang
- Department of Medicinal Chemistry, School of Pharmacy, Second Military Medical University (Naval Medical University), 325 Guohe Road, Shanghai 200433, People's Republic of China
| | - Jie Tu
- Department of Medicinal Chemistry, School of Pharmacy, Second Military Medical University (Naval Medical University), 325 Guohe Road, Shanghai 200433, People's Republic of China
| | - Wanzhen Yang
- Department of Medicinal Chemistry, School of Pharmacy, Second Military Medical University (Naval Medical University), 325 Guohe Road, Shanghai 200433, People's Republic of China
| | - Na Liu
- Department of Medicinal Chemistry, School of Pharmacy, Second Military Medical University (Naval Medical University), 325 Guohe Road, Shanghai 200433, People's Republic of China
| | - Wei Wang
- State Key Laboratory of Bioengineering Reactor, and Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science & Technology, 130 Meilong Road, Shanghai 200237, China
- Department of Pharmacology and Toxicology, College of Pharmacy, and BIO5 Institute, University of Arizona, 1703 E. Mabel Street, P.O. Box 210207, Tucson, Arizona 85721-0207, United States
| | - Chunquan Sheng
- Department of Medicinal Chemistry, School of Pharmacy, Second Military Medical University (Naval Medical University), 325 Guohe Road, Shanghai 200433, People's Republic of China
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Singha R, Aggarwal R, Sanyal K. Negative regulation of biofilm development by the CUG-Ser1 clade-specific histone H3 variant is dependent on the canonical histone chaperone CAF-1 complex in Candida albicans. Mol Microbiol 2023; 119:574-585. [PMID: 36855815 DOI: 10.1111/mmi.15050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Revised: 02/21/2023] [Accepted: 02/26/2023] [Indexed: 03/02/2023]
Abstract
The CUG-Ser1 clade-specific histone H3 variant (H3VCTG ) has been reported to be a negative regulator of planktonic to biofilm growth transition in Candida albicans. The preferential binding of H3VCTG at the biofilm gene promoters makes chromatin repressive for the biofilm mode of growth. The two evolutionarily conserved chaperone complexes involved in incorporating histone H3 are CAF-1 and HIRA. In this study, we sought to identify the chaperone complex(es) involved in loading H3VCTG . We demonstrate that C. albicans cells lacking either Cac1 or Cac2 subunit of the CAF-1 chaperone complex, exhibit a hyper-filamentation phenotype on solid surfaces and form more robust biofilms than wild-type cells, thereby mimicking the phenotype of the H3VCTG null mutant. None of the subunits of the HIRA chaperone complex shows any significant difference in biofilm growth as compared to the wild type. The occupancy of H3VCTG is found to be significantly reduced at the promoters of biofilm genes in the absence of CAF-1 subunits. Hence, we provide evidence that CAF-1, a chaperone known to load canonical histone H3 in mammalian cells, is involved in chaperoning of variant histone H3VCTG at the biofilm gene promoters in C. albicans. Our findings also illustrate the acquisition of an unconventional role of the CAF-1 chaperone complex in morphogenesis in C. albicans.
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Affiliation(s)
- Rima Singha
- Molecular Mycology Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India
| | - Rashi Aggarwal
- Molecular Mycology Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India
| | - Kaustuv Sanyal
- Molecular Mycology Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India
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3
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Du J, Dong Y, Zhao H, Peng L, Wang Y, Yu Q, Li M. Transcriptional regulation of autophagy, cell wall stress response and pathogenicity by Pho23 in C. albicans. FEBS J 2023; 290:855-871. [PMID: 36152022 DOI: 10.1111/febs.16636] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 09/02/2022] [Accepted: 09/20/2022] [Indexed: 02/04/2023]
Abstract
The modification of chromatin by histone deacetylases (HDACs) has critical roles in transcriptional regulation. In this study, we identified the Rpd3 HDAC complex component Pho23 in Candida albicans and explored its role in the transcriptional regulation of physiological processes. PHO23 deletion increased autophagic activity and upregulated the transcription of ATG genes. Moreover, the deletion of PHO23 severely impaired cell wall stress resistance and reduced the cell wall integrity (CWI) pathway in response to cell wall stress. Furthermore, the pho23Δ/Δ mutant had partial defects in hyphal development and protease secretion, which were associated with the downregulation of genes involved in hyphal development (e.g. HWP1, ALS3 and ECE1) and genes encoding secreted aspartic proteases (e.g. SAP4, SAP5, SAP6 and SAP9). In addition, the deletion of PHO23 strongly attenuated systemic infection and kidney fungal burden in mice, demonstrating that Pho23 is required for the virulence of C. albicans. Together, our results revealed that Pho23 regulates many key physiological processes in C. albicans at the transcriptional level. These data also shed light on the potential for exploiting Rpd3 HDAC complex-related proteins as antifungal targets.
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Affiliation(s)
- Jiawen Du
- Department of Microbiology, College of Life Sciences, Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China
| | - Yixuan Dong
- Department of Microbiology, College of Life Sciences, Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China
| | - He Zhao
- Department of Microbiology, College of Life Sciences, Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China
| | - Liping Peng
- Department of Microbiology, College of Life Sciences, Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China
| | - Yao Wang
- Department of Microbiology, College of Life Sciences, Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China
| | - Qilin Yu
- Department of Microbiology, College of Life Sciences, Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China
| | - Mingchun Li
- Department of Microbiology, College of Life Sciences, Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China
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4
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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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5
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Abstract
During induced differentiation, the process often involves a commitment event, after which induced cells, when returned to noninducing conditions, continue to differentiate. The commitment event is rarely identified. Candida albicans differentiates from the white to opaque phenotype, a prerequisite for mating and a process accompanying colonization of the lower gastrointestinal tract and skin. In analyses of white cell populations induced to synchronously differentiate from the white to opaque phenotype, opaque commitment occurs at approximately the same time as evagination and chitin ring formation in the process of daughter cell formation, several hours after the master switch gene WOR1 is upregulated. Mutational analyses of transcription factor binding regions P1, P2, P3, P4, and P6 of the WOR1 promoter reveal that individual deletion of any of the five transcription factor binding regions does not eliminate morphological differentiation to the opaque cell phenotype under opaque-inducing conditions, but individual deletion of P2, P3, or P4, blocks opaque commitment and maintenance of the opaque phenotype after transition to noninducing conditions. These results suggest that commitment occurs at the level of the WOR1 promoter and that morphological differentiation can be dissociated from phenotypic commitment.
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Mundodi V, Choudhary S, Smith AD, Kadosh D. Global translational landscape of the Candida albicans morphological transition. G3-GENES GENOMES GENETICS 2021; 11:6046988. [PMID: 33585865 PMCID: PMC7849906 DOI: 10.1093/g3journal/jkaa043] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Accepted: 12/01/2020] [Indexed: 12/14/2022]
Abstract
Candida albicans, a major human fungal pathogen associated with high mortality and/or morbidity rates in a wide variety of immunocompromised individuals, undergoes a reversible morphological transition from yeast to filamentous cells that is required for virulence. While previous studies have identified and characterized global transcriptional mechanisms important for driving this transition, as well as other virulence properties, in C. albicans and other pathogens, considerably little is known about the role of genome-wide translational mechanisms. Using ribosome profiling, we report the first global translational profile associated with C. albicans morphogenesis. Strikingly, many genes involved in pathogenesis, filamentation, and the response to stress show reduced translational efficiency (TE). Several of these genes are known to be strongly induced at the transcriptional level, suggesting that a translational fine-tuning mechanism is in place. We also identify potential upstream open reading frames (uORFs), associated with genes involved in pathogenesis, and novel ORFs, several of which show altered TE during filamentation. Using a novel bioinformatics method for global analysis of ribosome pausing that will be applicable to a wide variety of genetic systems, we demonstrate an enrichment of ribosome pausing sites in C. albicans genes associated with protein synthesis and cell wall functions. Altogether, our results suggest that the C. albicans morphological transition, and most likely additional virulence processes in fungal pathogens, is associated with widespread global alterations in TE that do not simply reflect changes in transcript levels. These alterations affect the expression of many genes associated with processes essential for virulence and pathogenesis.
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Affiliation(s)
- Vasanthakrishna Mundodi
- Department of Microbiology, Immunology and Molecular Genetics, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Saket Choudhary
- Department of Computational Biology and Bioinformatics, University of Southern California, Los Angeles, CA 90089, USA
| | - Andrew D Smith
- Department of Computational Biology and Bioinformatics, University of Southern California, Los Angeles, CA 90089, USA
| | - David Kadosh
- Department of Microbiology, Immunology and Molecular Genetics, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
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Vico SH, Prieto D, Monge RA, Román E, Pla J. The Glyoxylate Cycle Is Involved in White-Opaque Switching in Candida albicans. J Fungi (Basel) 2021; 7:jof7070502. [PMID: 34202465 PMCID: PMC8304919 DOI: 10.3390/jof7070502] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 06/21/2021] [Accepted: 06/22/2021] [Indexed: 11/16/2022] Open
Abstract
Candida albicans is a commensal yeast that inhabits the gastrointestinal tract of humans. The master regulator of the white-opaque transition WOR1 has been implicated in the adaptation to this commensal status. A proteomic analysis of cells overexpressing this transcription factor (WOR1OE) suggested an altered metabolism of carbon sources and a phenotypic analysis confirmed this alteration. The WOR1OE cells are deficient in using trehalose and xylose and are unable to use 2C sources, which is consistent with a reduction in the amount of Icl1, the isocitrate lyase enzyme. The icl1Δ/Δ mutants overexpressing WOR1 are deficient in the production of phloxine B positive cells, a main characteristic of opaque cells, a phenotype also observed in mating type hemizygous mtla1Δ icl1Δ/Δ cells, suggesting the involvement of Icl1 in the adaptation to the commensal state. In fact, icl1Δ/Δ cells have reduced fitness in mouse gastrointestinal tract as compared with essentially isogenic heterozygous ICL1/icl1Δ, but overproduction of WOR1 in an icl1Δ/Δ mutant does not restore fitness. These results implicate the glyoxylate shunt in the adaptation to commensalism of C. albicans by mechanisms that are partially independent of WOR1.
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The Roles of Chromatin Accessibility in Regulating the Candida albicans White-Opaque Phenotypic Switch. J Fungi (Basel) 2021; 7:jof7010037. [PMID: 33435404 PMCID: PMC7826875 DOI: 10.3390/jof7010037] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 01/05/2021] [Accepted: 01/07/2021] [Indexed: 12/18/2022] Open
Abstract
Candida albicans, a diploid polymorphic fungus, has evolved a unique heritable epigenetic program that enables reversible phenotypic switching between two cell types, referred to as “white” and “opaque”. These cell types are established and maintained by distinct transcriptional programs that lead to differences in metabolic preferences, mating competencies, cellular morphologies, responses to environmental signals, interactions with the host innate immune system, and expression of approximately 20% of genes in the genome. Transcription factors (defined as sequence specific DNA-binding proteins) that regulate the establishment and heritable maintenance of the white and opaque cell types have been a primary focus of investigation in the field; however, other factors that impact chromatin accessibility, such as histone modifying enzymes, chromatin remodelers, and histone chaperone complexes, also modulate the dynamics of the white-opaque switch and have been much less studied to date. Overall, the white-opaque switch represents an attractive and relatively “simple” model system for understanding the logic and regulatory mechanisms by which heritable cell fate decisions are determined in higher eukaryotes. Here we review recent discoveries on the roles of chromatin accessibility in regulating the C. albicans white-opaque phenotypic switch.
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9
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Zhu W, Fan X, Zhao Q, Xu Y, Wang X, Chen J. Bre1 and Ubp8 regulate H2B mono-ubiquitination and the reversible yeast-hyphae transition in Candida albicans. Mol Microbiol 2020; 115:332-343. [PMID: 33010070 DOI: 10.1111/mmi.14619] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 09/23/2020] [Accepted: 09/26/2020] [Indexed: 02/06/2023]
Abstract
The reversible yeast-hyphae transition of the human fungal pathogen Candida albicans is tightly linked to its pathogenicity. In this study, we show that histone H2B mono-ubiquitination (H2Bub) at lysine 123 was maintained at a low level in the yeast state, whereas it increased significantly during yeast-to-hyphae transition and decreased when hyphae converted to yeast. The increased H2Bub level is correlated with activation of the hyphal program. H2B ubiquitination and deubiquitination are dynamically regulated by the E3 ligase Bre1 and the deubiquitinase Ubp8 during the reversible yeast-hyphae transition. The functions of Bre1 and Ubp8 in hypha-specific gene (HSG) regulation appears to be direct because both are recruited to the coding regions of HSGs during hyphal induction. The sequential recruitment of Bre1 and Ubp8 to HSGs coding regions is important for the initiation and maintenance of HSG expression. Additionally, Ubp8 contributes to the pathogenicity of C. albicans during early infection in a mouse model. Our study is the first to link H2B ubiquitination to the morphological plasticity and pathogenicity of the human fungal pathogen C. albicans and shed light on potential antifungal treatments.
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Affiliation(s)
- Wencheng Zhu
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Xueyi Fan
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Qun Zhao
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Yinxing Xu
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Xiongjun Wang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Jiangye Chen
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
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Chen J, Liu Q, Zeng L, Huang X. Protein Acetylation/Deacetylation: A Potential Strategy for Fungal Infection Control. Front Microbiol 2020; 11:574736. [PMID: 33133044 PMCID: PMC7579399 DOI: 10.3389/fmicb.2020.574736] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Accepted: 09/17/2020] [Indexed: 12/13/2022] Open
Abstract
Protein acetylation is a universal post-translational modification that fine-tunes the major cellular processes of many life forms. Although the mechanisms regulating protein acetylation have not been fully elucidated, this modification is finely tuned by both enzymatic and non-enzymatic mechanisms. Protein deacetylation is the reverse process of acetylation and is mediated by deacetylases. Together, protein acetylation and deacetylation constitute a reversible regulatory protein acetylation network. The recent application of mass spectrometry-based proteomics has led to accumulating evidence indicating that reversible protein acetylation may be related to fungal virulence because a substantial amount of virulence factors are acetylated. Additionally, the relationship between protein acetylation/deacetylation and fungal drug resistance has also been proven and the potential of deacetylase inhibitors as an anti-infective treatment has attracted attention. This review aimed to summarize the research progress in understanding fungal protein acetylation/deacetylation and discuss the mechanism of its mediation in fungal virulence, providing novel targets for the treatment of fungal infection.
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Affiliation(s)
- Junzhu Chen
- Department of Medical Microbiology, School of Medicine, Nanchang University, Nanchang, China
| | - Qiong Liu
- Department of Medical Microbiology, School of Medicine, Nanchang University, Nanchang, China
| | - Lingbing Zeng
- The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Xiaotian Huang
- Department of Medical Microbiology, School of Medicine, Nanchang University, Nanchang, China
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11
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Abstract
Candida albicans, a pervasive opportunistic pathogen, undergoes a unique phenotypic transition from a "white" phenotype to an "opaque" phenotype. The switch to opaque impacts gene expression, cell morphology, wall structure, metabolism, biofilm formation, mating, virulence, and colonization of the skin and gastrointestinal (GI) tract. Although the regulation of switching is complex, a paradigm has evolved from a number of studies, in which, in its simplest form, the transcription factors Efg1 and Wor1 play central roles. When EFG1 is upregulated under physiological conditions, it represses WOR1, an activator of white-to-opaque switching, and the cell expresses the white phenotype; when EFG1 is downregulated, WOR1 is derepressed and activates expression of the opaque phenotype. Deletion of either EFG1 or WOR1 supports this yin-yang model of regulation. Here, we demonstrate that this simple model is insufficient, since strains in which WOR1 and EFG1 are simultaneously deleted can still be induced to switch en masse from white to opaque. Opaque cells of double mutants (efg1-/- wor1-/- ) are enlarged and elongate, form an enlarged vacuole, upregulate mCherry under the control of an opaque-specific promoter, form opaque cell wall pimples, express the opaque phenotype in lower GI colonization, and, if MTL homozygous, form conjugation tubes in response to pheromone and mate. These results can be explained if the basic and simplified model is expanded to include a WOR1-independent alternative opaque pathway repressed by EFG1 IMPORTANCE The switch from white to opaque in Candida albicans was discovered 33 years ago, but it is still unclear how it is regulated. A regulatory paradigm has emerged in which two transacting factors, Efg1 and Wor1, play central roles, Efg1 as a repressor of WOR1, which encodes an activator of the transition to the opaque phenotype. However, we show here that if both EFG1 and WOR1 are deleted simultaneously, bona fide opaque cells can still be induced en masse These results are not compatible with the simple paradigm, suggesting that an alternative opaque pathway (AOP) exists, which can activate expression of opaque and, like WOR1, is repressed by EFG1.
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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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Kim T, Lee SH, Oh YT, Jeon J. A Histone Deacetylase, MoHDA1 Regulates Asexual Development and Virulence in the Rice Blast Fungus. THE PLANT PATHOLOGY JOURNAL 2020; 36:314-322. [PMID: 32788890 PMCID: PMC7403517 DOI: 10.5423/ppj.oa.06.2020.0099] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 07/14/2020] [Accepted: 07/19/2020] [Indexed: 06/11/2023]
Abstract
Interplay between histone acetylation and deacetylation is one of the key components in epigenetic regulation of transcription. Here we report the requirement of Mo-HDA1-mediated histone deacetylation during asexual development and pathogenesis for the rice blast fungus, Magnaporthe oryzae. Structural similarity and phylogenetic analysis suggested that MoHDA1 is an ortholog of Saccharomyces cerevisiae Hda1, which is a representative member of class II histone deacetylases. Targeted deletion of MoHDA1 caused a little decrease in radial growth and large reduction in asexual sporulation. Comparison of acetylation levels for H3K9 and H3K14 showed that lack of MoHDA1 gene led to significant increase in H3K9 and H3K14 acetylation level, compared to the wild-type and complementation strain, confirming that it is a bona fide histone deacetylase. Expression analysis on some of the key genes involved in asexual reproduction under sporulation-promoting condition showed almost no differences among strains, except for MoCON6 gene, which was up-regulated more than 6-fold in the mutant than wild-type. Although the deletion mutant displayed little defects in germination and subsequent appressorium formation, the mutant was compromised in its ability to cause disease. Woundinoculation showed that the mutant is impaired in invasive growth as well. We found that the mutant was defective in appressorium-mediated penetration of host, but did not lose the ability to grow on the media containing H2O2. Taken together, our data suggest that MoHDA1-dependent histone deacetylation is important for efficient asexual development and infection of host plants in M. oryzae.
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Affiliation(s)
- Taehyun Kim
- Department of Biotechnology, College of Life and Applied Sciences, Yeungnam University, Gyeongsan 38541, Korea
| | - Song Hee Lee
- Department of Biotechnology, College of Life and Applied Sciences, Yeungnam University, Gyeongsan 38541, Korea
- Plant Immunity Research Center, Seoul National University, Seoul 08826, Korea
| | - Young Taek Oh
- Freshwater Bioresources Utilization Division, Nakdonggang National Institute of Biological Resources, Sangju 37242, Korea
| | - Junhyun Jeon
- Department of Biotechnology, College of Life and Applied Sciences, Yeungnam University, Gyeongsan 38541, Korea
- Plant Immunity Research Center, Seoul National University, Seoul 08826, Korea
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14
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Chromatin Structure and Drug Resistance in Candida spp. J Fungi (Basel) 2020; 6:jof6030121. [PMID: 32751495 PMCID: PMC7559719 DOI: 10.3390/jof6030121] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 07/21/2020] [Accepted: 07/25/2020] [Indexed: 12/14/2022] Open
Abstract
Anti-microbial resistance (AMR) is currently one of the most serious threats to global human health and, appropriately, research to tackle AMR garnishes significant investment and extensive attention from the scientific community. However, most of this effort focuses on antibiotics, and research into anti-fungal resistance (AFR) is vastly under-represented in comparison. Given the growing number of vulnerable, immunocompromised individuals, as well as the positive impact global warming has on fungal growth, there is an immediate urgency to tackle fungal disease, and the disturbing rise in AFR. Chromatin structure and gene expression regulation play pivotal roles in the adaptation of fungal species to anti-fungal stress, suggesting a potential therapeutic avenue to tackle AFR. In this review we discuss both the genetic and epigenetic mechanisms by which chromatin structure can dictate AFR mechanisms and will present evidence of how pathogenic yeast, specifically from the Candida genus, modify chromatin structure to promote survival in the presence of anti-fungal drugs. We also discuss the mechanisms by which anti-chromatin therapy, specifically lysine deacetylase inhibitors, influence the acquisition and phenotypic expression of AFR in Candida spp. and their potential as effective adjuvants to mitigate against AFR.
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15
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Su S, Li X, Yang X, Li Y, Chen X, Sun S, Jia S. Histone acetylation/deacetylation in Candida albicans and their potential as antifungal targets. Future Microbiol 2020; 15:1075-1090. [PMID: 32854542 DOI: 10.2217/fmb-2019-0343] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Recently, the incidence of invasive fungal infections has significantly increased. Candida albicans (C. albicans) is the most common opportunistic fungal pathogen that infects humans. The limited number of available antifungal agents and the emergence of drug resistance pose difficulties to treatment, thus new antifungals are urgently needed. Through their functions in DNA replication, DNA repair and transcription, histone acetyltransferases (HATs) and histone deacetylases (HDACs) perform essential functions relating to growth, virulence, drug resistance and stress responses of C. albicans. Here, we summarize the physiological and pathological functions of HATs/HDACs, potential antifungal targets and underlying antifungal compounds that impact histone acetylation and deacetylation. We anticipate this review will stimulate the identification of new HAT/HDAC-related antifungal targets and antifungal agents.
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Affiliation(s)
- Shan Su
- School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan 250012, Shandong Province, People’s Republic of China
| | - Xiuyun Li
- Department of Pharmacy, Qilu Children’s Hospital, Shandong University, Jinan 250022, China
| | - Xinmei Yang
- Department of Clinical Pharmacy, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan 250014, Shandong Province, People’s Republic of China
| | - Yiman Li
- School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan 250012, Shandong Province, People’s Republic of China
| | - Xueqi Chen
- School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan 250012, Shandong Province, People’s Republic of China
| | - Shujuan Sun
- Department of Clinical Pharmacy, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan 250014, Shandong Province, People’s Republic of China
- Department of Clinical Pharmacy, The First Affiliated Hospital of Shandong First Medical University, Jinan 250014, Shandong Province, People’s Republic of China
| | - Shuang Jia
- Department of Clinical Pharmacy, The First Affiliated Hospital of Shandong First Medical University, Jinan 250014, Shandong Province, People’s Republic of China
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16
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Li H, Li Y, Sun T, Du W, Zhang Z, Li D, Ding C. Integrative Proteome and Acetylome Analyses of Murine Responses to Cryptococcus neoformans Infection. Front Microbiol 2020; 11:575. [PMID: 32362878 PMCID: PMC7181412 DOI: 10.3389/fmicb.2020.00575] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Accepted: 03/16/2020] [Indexed: 01/09/2023] Open
Abstract
Cryptococcus neoformans is a causative agent for pulmonary infection and meningoencephalitis. Understanding the host’s response to C. neoformans infection is critical for developing effective treatment. Even though some have elucidated the host response at the transcriptome level, little is known about how it modulates its defense machinery through the proteome mechanism or how protein posttranslational modification responds to the infection. In this work, we employed a murine infection model and mass spectrometry to systematically determine the proteome and acetylome statuses of lungs and brains in the early stage of infection. To extensively analyze the host response, we integrated the proteome data to the transcriptome results. Critical genes, including genes involved in phagosome, lysosome, and platelet activation are significantly altered in protein and gene expression during infection. In the acetylome analysis, we demonstrated that lung and brain tissues differentially regulate protein acetylation during infection. The three primary groups of proteins altered in acetylation status are histones, proteins involved in glucose and fatty acid metabolism, and proteins from the immune system. These analyses provide an integrative regulation network of the host responding to C. neoformans and shed new light on understanding the host’s regulation mechanism when responding to C. neoformans.
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Affiliation(s)
- Hailong Li
- College of Life and Health Sciences, Northeastern University, Shenyang, China
| | - Yanjian Li
- College of Life and Health Sciences, Northeastern University, Shenyang, China
| | - Tianshu Sun
- Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases, Beijing, China.,Central Research Laboratory, Department of Scientific Research, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Wei Du
- College of Life and Health Sciences, Northeastern University, Shenyang, China
| | - Zhijie Zhang
- Clinical Laboratory, Shengjing Hospital of China Medical University, Shenyang, China
| | - Dancheng Li
- Software College, Northeastern University, Shenyang, China
| | - Chen Ding
- College of Life and Health Sciences, Northeastern University, Shenyang, China.,Key Laboratory of Data Analytics and Optimization for Smart Industry, Northeastern University, Shenyang, China
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17
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Li Y, Li H, Sui M, Li M, Wang J, Meng Y, Sun T, Liang Q, Suo C, Gao X, Li C, Li Z, Du W, Zhang B, Sai S, Zhang Z, Ye J, Wang H, Yue S, Li J, Zhong M, Chen C, Qi S, Lu L, Li D, Ding C. Fungal acetylome comparative analysis identifies an essential role of acetylation in human fungal pathogen virulence. Commun Biol 2019; 2:154. [PMID: 31069264 PMCID: PMC6494858 DOI: 10.1038/s42003-019-0419-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 04/08/2019] [Indexed: 11/09/2022] Open
Abstract
Lysine acetylation is critical in regulating important biological processes in many organisms, yet little is known about acetylome evolution and its contribution to phenotypic diversity. Here, we compare the acetylomes of baker's yeast and the three deadliest human fungal pathogens, Cryptococcus neoformans, Candida albicans, and Aspergillus fumigatus. Using mass spectrometry enriched for acetylated peptides together with public data from Saccharomyces cerevisiae, we show that fungal acetylomes are characterized by dramatic evolutionary dynamics and limited conservation in core biological processes. Notably, the levels of protein acetylation in pathogenic fungi correlate with their pathogenicity. Using gene knockouts and pathogenicity assays in mice, we identify deacetylases with critical roles in virulence and protein translation elongation. Finally, through mutational analysis of deactylation motifs we find evidence of positive selection at specific acetylation motifs in fungal pathogens. These results shed new light on the pathogenicity regulation mechanisms underlying the evolution of fungal acetylomes.
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Affiliation(s)
- Yanjian Li
- College of Life and Health Sciences, Northeastern University, Shenyang, China
| | - Hailong Li
- College of Life and Health Sciences, Northeastern University, Shenyang, China
| | - Mingfei Sui
- Software College, Northeastern University, Shenyang, China
| | - Minghui Li
- College of Life and Health Sciences, Northeastern University, Shenyang, China
| | - Jiamei Wang
- College of Life and Health Sciences, Northeastern University, Shenyang, China
| | - Yang Meng
- College of Life and Health Sciences, Northeastern University, Shenyang, China
| | - Tianshu Sun
- Department of Scientific Research, Central Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Science, Beijing, China
- Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases, Beijing, China
| | - Qiaojing Liang
- College of Life and Health Sciences, Northeastern University, Shenyang, China
| | - Chenhao Suo
- College of Life and Health Sciences, Northeastern University, Shenyang, China
| | - Xindi Gao
- College of Life and Health Sciences, Northeastern University, Shenyang, China
| | - Chao Li
- College of Life and Health Sciences, Northeastern University, Shenyang, China
| | - Zhuoran Li
- College of Life and Health Sciences, Northeastern University, Shenyang, China
| | - Wei Du
- College of Life and Health Sciences, Northeastern University, Shenyang, China
| | - Baihua Zhang
- SINO-Dutch Biomedical and Information Engineering School, Northeastern University, Shenyang, China
| | - Sixiang Sai
- School of Medicine, Binzhou Medical University, Yantai, China
| | | | - Jing Ye
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Hongchen Wang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Shang Yue
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Jiayi Li
- College of Life and Health Sciences, Northeastern University, Shenyang, China
- Neural Plasticity and Repair Unit, Wallenberg Neuroscience Center, Lund University, Lund, Sweden
| | - Manli Zhong
- College of Life and Health Sciences, Northeastern University, Shenyang, China
| | - Changbin Chen
- Unit of Pathogenic Fungal Infection & Host Immunity, CAS Key Laboratory of Molecular Virology & Immunology, Institute Pasteur of Shanghai, Chinese Academy of Science, Shanghai, China
| | - Shouliang Qi
- SINO-Dutch Biomedical and Information Engineering School, Northeastern University, Shenyang, China
| | - Ling Lu
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Dancheng Li
- Software College, Northeastern University, Shenyang, China
| | - Chen Ding
- College of Life and Health Sciences, Northeastern University, Shenyang, China
- Key Laboratory of Data Analytics and Optimization for Smart Industry, Northeastern University, Shenyang, China
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18
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Abstract
Fungi are prone to phenotypic instability, that is, the vegetative phase of these organisms, be they yeasts or molds, undergoes frequent switching between two or more behaviors, often with different morphologies, but also sometime having different physiologies without any obvious morphological outcome. In the context of industrial utilization of fungi, this can have a negative impact on the maintenance of strains and/or on their productivity. Instabilities have been shown to result from various mechanisms, either genetic or epigenetic. This chapter will review different types of instabilities and discuss some lesser-known ones, mostly in filamentous fungi, while it will direct readers to additional literature in the case of well-known phenomena such as the amyloid prions or fungal senescence. It will present in depth the "white/opaque" switch of Candida albicans and the "crippled growth" degeneration of the model fungus Podospora anserina. These are two of the most thoroughly studied epigenetic phenotypic switches. I will also discuss the "sectors" presented by many filamentous ascomycetes, for which a prion-based model exists but is not demonstrated. Finally, I will also describe intriguing examples of phenotypic instability for which an explanation has yet to be provided.
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19
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Wang X, Zhu W, Chang P, Wu H, Liu H, Chen J. Merge and separation of NuA4 and SWR1 complexes control cell fate plasticity in Candida albicans. Cell Discov 2018; 4:45. [PMID: 30109121 PMCID: PMC6089883 DOI: 10.1038/s41421-018-0043-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 04/11/2018] [Accepted: 05/25/2018] [Indexed: 12/16/2022] Open
Abstract
Phenotypic plasticity is common in development. Candida albicans, a polymorphic fungal pathogen of humans, possesses the unique ability to achieve rapid and reversible cell fate between unicellular form (yeast) and multicellular form (hypha) in response to environmental cues. The NuA4 histone acetyltransferase activity and Hda1 histone deacetylase activity have been reported to be required for hyphal initiation and maintenance. However, how Hda1 and NuA4 regulate hyphal elongation is not clear. NuA4 histone acetyltransferase and SWR1 chromatin remodeling complexes are conserved from yeast to human, which may have merged together to form a larger TIP60 complex since the origin of metazoan. In this study, we show a dynamic merge and separation of NuA4 and SWR1 complexes in C. albicans. NuA4 and SWR1 merge together in yeast state and separate into two distinct complexes in hyphal state. We demonstrate that acetylation of Eaf1 K173 controls the interaction between the two complexes. The YEATS domain of Yaf9 in C. albicans can recognize an acetyl-lysine of the Eaf1 and mediate the Yaf9-Eaf1 interaction. The reversible acetylation and deacetylation of Eaf1 by Esa1 and Hda1 control the merge and separation of NuA4 and SWR1, and this regulation is triggered by Brg1 recruitment of Hda1 to chromatin in response nutritional signals that sustain hyphal elongation. We have also observed an orchestrated promoter association of Esa1, Hda1, Swr1, and H2A.Z during the reversible yeast-hyphae transitions. This is the first discovery of a regulated merge of the NuA4 and SWR1 complexes that controls cell fate determination and this regulation may be conserved in polymorphic fungi.
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Affiliation(s)
- Xiongjun Wang
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai, 200031 China
| | - Wencheng Zhu
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai, 200031 China
| | - Peng Chang
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai, 200031 China
| | - Hongyu Wu
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai, 200031 China
| | - Haoping Liu
- Department of Biological Chemistry, University of California, Irvine, CA 92697 USA
| | - Jiangye Chen
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai, 200031 China
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20
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Sac7 and Rho1 regulate the white-to-opaque switching in Candida albicans. Sci Rep 2018; 8:875. [PMID: 29343748 PMCID: PMC5772354 DOI: 10.1038/s41598-018-19246-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 12/19/2017] [Indexed: 11/17/2022] Open
Abstract
Candida albicans cells homozygous at the mating-type locus stochastically undergo the white-to-opaque switching to become mating-competent. This switching is regulated by a core circuit of transcription factors organized through interlocking feedback loops around the master regulator Wor1. Although a range of distinct environmental cues is known to induce the switching, the pathways linking the external stimuli to the central control mechanism remains largely unknown. By screening a C. albicans haploid gene-deletion library, we found that SAC7 encoding a GTPase-activating protein of Rho1 is required for the white-to-opaque switching. We demonstrate that Sac7 physically associates with Rho1-GTP and the constitutively active Rho1G18V mutant impairs the white-to-opaque switching while the inactive Rho1D124A mutant promotes it. Overexpressing WOR1 in both sac7Δ/Δ and rho1G18V cells suppresses the switching defect, indicating that the Sac7/Rho1 module acts upstream of Wor1. Furthermore, we provide evidence that Sac7/Rho1 functions in a pathway independent of the Ras/cAMP pathway which has previously been positioned upstream of Wor1. Taken together, we have discovered new regulators and a signaling pathway that regulate the white-to-opaque switching in the most prevalent human fungal pathogen C. albicans.
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21
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Rai LS, Singha R, Brahma P, Sanyal K. Epigenetic determinants of phenotypic plasticity in Candida albicans. FUNGAL BIOL REV 2018. [DOI: 10.1016/j.fbr.2017.07.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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22
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The Paralogous Histone Deacetylases Rpd3 and Rpd31 Play Opposing Roles in Regulating the White-Opaque Switch in the Fungal Pathogen Candida albicans. mBio 2016; 7:mBio.01807-16. [PMID: 27935838 PMCID: PMC5111407 DOI: 10.1128/mbio.01807-16] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Chromatin modifications affect gene regulation in response to environmental stimuli in numerous biological processes. For example, N-acetyl-glucosamine and CO2 induce a morphogenetic conversion between white (W) and opaque (O) cells in MTL (mating-type locus) homozygous and heterozygous (a/α) strains of the human fungal pathogen Candida albicans. Here, we identify 8 histone-modifying enzymes playing distinct roles in the regulation of W/O switching in MTL homozygous and heterozygous strains. Most strikingly, genetic removal of the paralogous genes RPD3 and RPD31, both of which encode almost identical orthologues of the yeast histone deacetylase (HDAC) Rpd3, reveals opposing roles in W/O switching of MTLa/α strains. We show that Rpd3 and Rpd31 functions depend on MTL genotypes. Strikingly, we demonstrate that Rpd3 and Rpd31, which are almost identical except for a divergent C-terminal extension present in Rpd31, exert their functions in distinct regulatory complexes referred to as CaRpd3L and CaRpd31S complexes. Moreover, we identify the Candida orf19.7185 product Ume1, the orthologue of yeast Ume1, as a shared core subunit of CaRpd3L and CaRpd31S. Mechanistically, we show that the opposing roles of Rpd3 and Rpd31 require their deacetylase activities. Importantly, CaRpd3L interacts with the heterodimeric transcriptional repressor a1/α2, thus controlling expression of WOR1 encoding the master regulator of W/O switching. Thus, our work provides novel insight about regulation mechanisms of W/O switching in MTLa/α strains. This is the first example of two highly conserved HDACs exerting opposing regulatory functions in the same process in a eukaryotic cell. RPD3-like histone deacetylases (also called class I HDACs) are conserved from unicellular eukaryotes to mammals. Specifically, the genome of the human fungal pathogen Candida albicans, the most frequent cause of invasive fungal infections of high morbidity and mortality, harbors two almost identical paralogous HDACs, Rpd3 and Rpd31. We show here for the first time that Rpd3 and Rpd31 acquired functional divergence related to a distinct C-terminal domain. Rpd3 and Rpd31 associate with different complexes in the control regions of the master regulator gene WOR1, which is required for white-opaque (W/O) morphogenesis, respectively. The ability to switch is important for fungal pathogenesis, since it enables distinct host niche colonization. This work is to the best of our knowledge the first description of two paralogous HDACs playing opposing functional roles in the same developmental process. Our work adds a new angle concerning the molecular understanding of HDACs in the regulation of cell fate decisions.
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23
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24
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Anderson MZ, Porman AM, Wang N, Mancera E, Huang D, Cuomo CA, Bennett RJ. A Multistate Toggle Switch Defines Fungal Cell Fates and Is Regulated by Synergistic Genetic Cues. PLoS Genet 2016; 12:e1006353. [PMID: 27711197 PMCID: PMC5053522 DOI: 10.1371/journal.pgen.1006353] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 09/09/2016] [Indexed: 11/18/2022] Open
Abstract
Heritable epigenetic changes underlie the ability of cells to differentiate into distinct cell types. Here, we demonstrate that the fungal pathogen Candida tropicalis exhibits multipotency, undergoing stochastic and reversible switching between three cellular states. The three cell states exhibit unique cellular morphologies, growth rates, and global gene expression profiles. Genetic analysis identified six transcription factors that play key roles in regulating cell differentiation. In particular, we show that forced expression of Wor1 or Efg1 transcription factors can be used to manipulate transitions between all three cell states. A model for tristability is proposed in which Wor1 and Efg1 are self-activating but mutually antagonistic transcription factors, thereby forming a symmetrical self-activating toggle switch. We explicitly test this model and show that ectopic expression of WOR1 can induce white-to-hybrid-to-opaque switching, whereas ectopic expression of EFG1 drives switching in the opposite direction, from opaque-to-hybrid-to-white cell states. We also address the stability of induced cell states and demonstrate that stable differentiation events require ectopic gene expression in combination with chromatin-based cues. These studies therefore experimentally test a model of multistate stability and demonstrate that transcriptional circuits act synergistically with chromatin-based changes to drive cell state transitions. We also establish close mechanistic parallels between phenotypic switching in unicellular fungi and cell fate decisions during stem cell reprogramming.
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Affiliation(s)
- Matthew Z. Anderson
- Department of Microbiology and Immunology, Brown University, Providence, Rhode Island, United States of America
| | - Allison M. Porman
- Department of Microbiology and Immunology, Brown University, Providence, Rhode Island, United States of America
| | - Na Wang
- Department of Microbiology and Immunology, Brown University, Providence, Rhode Island, United States of America
| | - Eugenio Mancera
- Department of Microbiology and Immunology, University of California San Francisco, San Francisco, California, United States of America
| | - Denis Huang
- Department of Microbiology and Immunology, Brown University, Providence, Rhode Island, United States of America
| | - Christina A. Cuomo
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Richard J. Bennett
- Department of Microbiology and Immunology, Brown University, Providence, Rhode Island, United States of America
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25
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Garnaud C, Champleboux M, Maubon D, Cornet M, Govin J. Histone Deacetylases and Their Inhibition in Candida Species. Front Microbiol 2016; 7:1238. [PMID: 27547205 PMCID: PMC4974301 DOI: 10.3389/fmicb.2016.01238] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 07/25/2016] [Indexed: 11/25/2022] Open
Abstract
Fungi are generally benign members of the human mucosal flora or live as saprophytes in the environment. However, they can become pathogenic, leading to invasive and life threatening infections in vulnerable patients. These invasive fungal infections are regarded as a major public health problem on a similar scale to tuberculosis or malaria. Current treatment for these infections is based on only four available drug classes. This limited therapeutic arsenal and the emergence of drug-resistant strains are a matter of concern due to the growing number of patients to be treated, and new therapeutic strategies are urgently needed. Adaptation of fungi to drug pressure involves transcriptional regulation, in which chromatin dynamics and histone modifications play a major role. Histone deacetylases (HDACs) remove acetyl groups from histones and actively participate in controlling stress responses. HDAC inhibition has been shown to limit fungal development, virulence, biofilm formation, and dissemination in the infected host, while also improving the efficacy of existing antifungal drugs toward Candida spp. In this article, we review the functional roles of HDACs and the biological effects of HDAC inhibitors on Candida spp., highlighting the correlations between their pathogenic effects in vitro and in vivo. We focus on how HDAC inhibitors could be used to treat invasive candidiasis while also reviewing recent developments in their clinical evaluation.
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Affiliation(s)
- Cécile Garnaud
- Laboratoire de Parasitologie-Mycologie, Institut de Biologie et de Pathologie, Centre Hospitalier Universitaire Grenoble AlpesGrenoble, France; Laboratoire TIMC-IMAG-TheREx, UMR 5525 CNRS-UGA, Université Grenoble AlpesGrenoble, France
| | - Morgane Champleboux
- Université Grenoble Alpes, Institut National de la Santé et de la Recherche Médicale U1038, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Biosciences and Biotechnology Institute of Grenoble - Large Scale Biology Laboratory Grenoble, France
| | - Danièle Maubon
- Laboratoire de Parasitologie-Mycologie, Institut de Biologie et de Pathologie, Centre Hospitalier Universitaire Grenoble AlpesGrenoble, France; Laboratoire TIMC-IMAG-TheREx, UMR 5525 CNRS-UGA, Université Grenoble AlpesGrenoble, France
| | - Muriel Cornet
- Laboratoire de Parasitologie-Mycologie, Institut de Biologie et de Pathologie, Centre Hospitalier Universitaire Grenoble AlpesGrenoble, France; Laboratoire TIMC-IMAG-TheREx, UMR 5525 CNRS-UGA, Université Grenoble AlpesGrenoble, France
| | - Jérôme Govin
- Université Grenoble Alpes, Institut National de la Santé et de la Recherche Médicale U1038, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Biosciences and Biotechnology Institute of Grenoble - Large Scale Biology Laboratory Grenoble, France
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26
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Systematic Genetic Screen for Transcriptional Regulators of the Candida albicans White-Opaque Switch. Genetics 2016; 203:1679-92. [PMID: 27280690 DOI: 10.1534/genetics.116.190645] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 05/23/2016] [Indexed: 02/04/2023] Open
Abstract
The human fungal pathogen Candida albicans can reversibly switch between two cell types named "white" and "opaque," each of which is stable through many cell divisions. These two cell types differ in their ability to mate, their metabolic preferences and their interactions with the mammalian innate immune system. A highly interconnected network of eight transcriptional regulators has been shown to control switching between these two cell types. To identify additional regulators of the switch, we systematically and quantitatively measured white-opaque switching rates of 196 strains, each deleted for a specific transcriptional regulator. We identified 19 new regulators with at least a 10-fold effect on switching rates and an additional 14 new regulators with more subtle effects. To investigate how these regulators affect switching rates, we examined several criteria, including the binding of the eight known regulators of switching to the control region of each new regulatory gene, differential expression of the newly found genes between cell types, and the growth rate of each mutant strain. This study highlights the complexity of the transcriptional network that regulates the white-opaque switch and the extent to which switching is linked to a variety of metabolic processes, including respiration and carbon utilization. In addition to revealing specific insights, the information reported here provides a foundation to understand the highly complex coupling of white-opaque switching to cellular physiology.
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27
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Tyc KM, Herwald SE, Hogan JA, Pierce JV, Klipp E, Kumamoto CA. The game theory of Candida albicans colonization dynamics reveals host status-responsive gene expression. BMC SYSTEMS BIOLOGY 2016; 10:20. [PMID: 26927448 PMCID: PMC4772284 DOI: 10.1186/s12918-016-0268-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 02/12/2016] [Indexed: 02/06/2023]
Abstract
Background The fungal pathogen Candida albicans colonizes the gastrointestinal (GI) tract of mammalian hosts as a benign commensal. However, in an immunocompromised host, the fungus is capable of causing life-threatening infection. We previously showed that the major transcription factor Efg1p is differentially expressed in GI-colonizing C. albicans cells dependent on the host immune status. To understand the mechanisms that underlie this host-dependent differential gene expression, we utilized mathematical modeling to dissect host-pathogen interactions. Specifically, we used principles of evolutionary game theory to study the mechanism that governs dynamics of EFG1 expression during C. albicans colonization. Results Mathematical modeling predicted that down-regulation of EFG1 expression within individual fungal cells occurred at different average rates in different hosts. Rather than using relatively transient signaling pathways to adapt to a new environment, we demonstrate that C. albicans overcomes the host defense strategy by modulating the activity of diverse fungal histone modifying enzymes that control EFG1 expression. Conclusion Based on our modeling and experimental results we conclude that C. albicans cells sense the local environment of the GI tract and respond to differences by altering EFG1 expression to establish optimal survival strategies. We show that the overall process is governed via modulation of epigenetic regulators of chromatin structure. Electronic supplementary material The online version of this article (doi:10.1186/s12918-016-0268-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Katarzyna M Tyc
- Theoretische Biophysik, Humboldt-Universität zu Berlin, Invalidenstraße 42, D-10115, Berlin, Germany. .,Present address: Department of Biochemistry, University of Utah, Salt Lake City, UT, 84112, USA.
| | - Sanna E Herwald
- Graduate Program in Molecular Microbiology, Sackler School of Graduate Biomedical Sciences and Department of Molecular Biology and Microbiology, Tufts University, Boston, MA, 02111, USA.
| | - Jennifer A Hogan
- Graduate Program in Molecular Microbiology, Sackler School of Graduate Biomedical Sciences and Department of Molecular Biology and Microbiology, Tufts University, Boston, MA, 02111, USA.
| | - Jessica V Pierce
- Graduate Program in Molecular Microbiology, Sackler School of Graduate Biomedical Sciences and Department of Molecular Biology and Microbiology, Tufts University, Boston, MA, 02111, USA. .,Genetics and Biochemistry Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA.
| | - Edda Klipp
- Theoretische Biophysik, Humboldt-Universität zu Berlin, Invalidenstraße 42, D-10115, Berlin, Germany.
| | - Carol A Kumamoto
- Graduate Program in Molecular Microbiology, Sackler School of Graduate Biomedical Sciences and Department of Molecular Biology and Microbiology, Tufts University, Boston, MA, 02111, USA. .,Department of Molecular Biology and Microbiology, Tufts University, 136 Harrison Ave., Boston, MA, 02111, USA.
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Schmoll M, Dattenböck C, Carreras-Villaseñor N, Mendoza-Mendoza A, Tisch D, Alemán MI, Baker SE, Brown C, Cervantes-Badillo MG, Cetz-Chel J, Cristobal-Mondragon GR, Delaye L, Esquivel-Naranjo EU, Frischmann A, Gallardo-Negrete JDJ, García-Esquivel M, Gomez-Rodriguez EY, Greenwood DR, Hernández-Oñate M, Kruszewska JS, Lawry R, Mora-Montes HM, Muñoz-Centeno T, Nieto-Jacobo MF, Nogueira Lopez G, Olmedo-Monfil V, Osorio-Concepcion M, Piłsyk S, Pomraning KR, Rodriguez-Iglesias A, Rosales-Saavedra MT, Sánchez-Arreguín JA, Seidl-Seiboth V, Stewart A, Uresti-Rivera EE, Wang CL, Wang TF, Zeilinger S, Casas-Flores S, Herrera-Estrella A. The Genomes of Three Uneven Siblings: Footprints of the Lifestyles of Three Trichoderma Species. Microbiol Mol Biol Rev 2016; 80:205-327. [PMID: 26864432 PMCID: PMC4771370 DOI: 10.1128/mmbr.00040-15] [Citation(s) in RCA: 125] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The genus Trichoderma contains fungi with high relevance for humans, with applications in enzyme production for plant cell wall degradation and use in biocontrol. Here, we provide a broad, comprehensive overview of the genomic content of these species for "hot topic" research aspects, including CAZymes, transport, transcription factors, and development, along with a detailed analysis and annotation of less-studied topics, such as signal transduction, genome integrity, chromatin, photobiology, or lipid, sulfur, and nitrogen metabolism in T. reesei, T. atroviride, and T. virens, and we open up new perspectives to those topics discussed previously. In total, we covered more than 2,000 of the predicted 9,000 to 11,000 genes of each Trichoderma species discussed, which is >20% of the respective gene content. Additionally, we considered available transcriptome data for the annotated genes. Highlights of our analyses include overall carbohydrate cleavage preferences due to the different genomic contents and regulation of the respective genes. We found light regulation of many sulfur metabolic genes. Additionally, a new Golgi 1,2-mannosidase likely involved in N-linked glycosylation was detected, as were indications for the ability of Trichoderma spp. to generate hybrid galactose-containing N-linked glycans. The genomic inventory of effector proteins revealed numerous compounds unique to Trichoderma, and these warrant further investigation. We found interesting expansions in the Trichoderma genus in several signaling pathways, such as G-protein-coupled receptors, RAS GTPases, and casein kinases. A particularly interesting feature absolutely unique to T. atroviride is the duplication of the alternative sulfur amino acid synthesis pathway.
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Affiliation(s)
- Monika Schmoll
- Austrian Institute of Technology, Department Health and Environment, Bioresources Unit, Tulln, Austria
| | - Christoph Dattenböck
- Austrian Institute of Technology, Department Health and Environment, Bioresources Unit, Tulln, Austria
| | | | | | - Doris Tisch
- Research Division Biotechnology and Microbiology, Institute of Chemical Engineering, TU Wien, Vienna, Austria
| | - Mario Ivan Alemán
- Cinvestav, Department of Genetic Engineering, Irapuato, Guanajuato, Mexico
| | - Scott E Baker
- Pacific Northwest National Laboratory, Richland, Washington, USA
| | - Christopher Brown
- University of Otago, Department of Biochemistry and Genetics, Dunedin, New Zealand
| | | | - José Cetz-Chel
- LANGEBIO, National Laboratory of Genomics for Biodiversity, Cinvestav-Irapuato, Guanajuato, Mexico
| | | | - Luis Delaye
- Cinvestav, Department of Genetic Engineering, Irapuato, Guanajuato, Mexico
| | | | - Alexa Frischmann
- Research Division Biotechnology and Microbiology, Institute of Chemical Engineering, TU Wien, Vienna, Austria
| | | | - Monica García-Esquivel
- LANGEBIO, National Laboratory of Genomics for Biodiversity, Cinvestav-Irapuato, Guanajuato, Mexico
| | | | - David R Greenwood
- The University of Auckland, School of Biological Sciences, Auckland, New Zealand
| | - Miguel Hernández-Oñate
- LANGEBIO, National Laboratory of Genomics for Biodiversity, Cinvestav-Irapuato, Guanajuato, Mexico
| | - Joanna S Kruszewska
- Polish Academy of Sciences, Institute of Biochemistry and Biophysics, Laboratory of Fungal Glycobiology, Warsaw, Poland
| | - Robert Lawry
- Lincoln University, Bio-Protection Research Centre, Lincoln, Canterbury, New Zealand
| | | | | | | | | | | | | | - Sebastian Piłsyk
- Polish Academy of Sciences, Institute of Biochemistry and Biophysics, Laboratory of Fungal Glycobiology, Warsaw, Poland
| | - Kyle R Pomraning
- Pacific Northwest National Laboratory, Richland, Washington, USA
| | - Aroa Rodriguez-Iglesias
- Austrian Institute of Technology, Department Health and Environment, Bioresources Unit, Tulln, Austria
| | | | | | - Verena Seidl-Seiboth
- Research Division Biotechnology and Microbiology, Institute of Chemical Engineering, TU Wien, Vienna, Austria
| | | | | | - Chih-Li Wang
- National Chung-Hsing University, Department of Plant Pathology, Taichung, Taiwan
| | - Ting-Fang Wang
- Academia Sinica, Institute of Molecular Biology, Taipei, Taiwan
| | - Susanne Zeilinger
- Research Division Biotechnology and Microbiology, Institute of Chemical Engineering, TU Wien, Vienna, Austria University of Innsbruck, Institute of Microbiology, Innsbruck, Austria
| | | | - Alfredo Herrera-Estrella
- LANGEBIO, National Laboratory of Genomics for Biodiversity, Cinvestav-Irapuato, Guanajuato, Mexico
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Histone deacetylase-mediated morphological transition in Candida albicans. J Microbiol 2015; 53:805-11. [DOI: 10.1007/s12275-015-5488-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 10/27/2015] [Accepted: 10/28/2015] [Indexed: 12/24/2022]
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Li X, Cai Q, Mei H, Zhou X, Shen Y, Li D, Liu W. The Rpd3/Hda1 family of histone deacetylases regulates azole resistance in Candida albicans. J Antimicrob Chemother 2015; 70:1993-2003. [DOI: 10.1093/jac/dkv070] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2014] [Accepted: 02/23/2015] [Indexed: 12/25/2022] Open
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Lu Y, Su C, Liu H. Candida albicans hyphal initiation and elongation. Trends Microbiol 2014; 22:707-14. [PMID: 25262420 DOI: 10.1016/j.tim.2014.09.001] [Citation(s) in RCA: 134] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 08/28/2014] [Accepted: 09/03/2014] [Indexed: 01/01/2023]
Abstract
The fungus Candida albicans is a benign member of the mucosal microbiota, but can cause mucosal infections and life-threatening disseminated invasive infections in susceptible individuals. The ability to switch between yeast, pseudohyphal, and hyphal growth forms (polymorphism) is one of the most investigated virulence attributes of C. albicans. Recent studies suggest that hyphal development in C. albicans requires two temporally linked regulations for initiation and maintenance of the hyphal transcriptional program. Hyphal initiation requires a rapid but temporary disappearance of the Nrg1 transcriptional repressor of hyphal morphogenesis. Hyphal maintenance requires active sensing of the surrounding environment, leading to exclusion of Nrg1 binding to promoters of hypha-specific genes or reduced NRG1 expression. We discuss recent advances in understanding the complex transcriptional regulation of hyphal gene expression. These provide molecular mechanisms underpinning the phenotypic plasticity of C. albicans polymorphism.
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Affiliation(s)
- Yang Lu
- Department of Biological Chemistry, University of California, Irvine, CA 92697, USA
| | - Chang Su
- Department of Biological Chemistry, University of California, Irvine, CA 92697, USA
| | - Haoping Liu
- Department of Biological Chemistry, University of California, Irvine, CA 92697, USA.
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Heitman J, Carter DA, Dyer PS, Soll DR. Sexual reproduction of human fungal pathogens. Cold Spring Harb Perspect Med 2014; 4:4/8/a019281. [PMID: 25085958 DOI: 10.1101/cshperspect.a019281] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
We review here recent advances in our understanding of sexual reproduction in fungal pathogens that commonly infect humans, including Candida albicans, Cryptococcus neoformans/gattii, and Aspergillus fumigatus. Where appropriate or relevant, we introduce findings on other species associated with human infections. In particular, we focus on rapid advances involving genetic, genomic, and population genetic approaches that have reshaped our view of how fungal pathogens evolve. Rather than being asexual, mitotic, and largely clonal, as was thought to be prevalent as recently as a decade ago, we now appreciate that the vast majority of pathogenic fungi have retained extant sexual, or parasexual, cycles. In some examples, sexual and parasexual unions of pathogenic fungi involve closely related individuals, generating diversity in the population but with more restricted recombination than expected from fertile, sexual, outcrossing and recombining populations. In other cases, species and isolates participate in global outcrossing populations with the capacity for considerable levels of gene flow. These findings illustrate general principles of eukaryotic pathogen emergence with relevance for other fungi, parasitic eukaryotic pathogens, and both unicellular and multicellular eukaryotic organisms.
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Affiliation(s)
- Joseph Heitman
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina 27710
| | - Dee A Carter
- School of Molecular Bioscience, University of Sydney, Sydney NSW 2006, Australia
| | - Paul S Dyer
- School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, United Kingdom
| | - David R Soll
- Department of Biology, University of Iowa, Iowa City, Iowa 52242
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Šťovíček V, Váchová L, Begany M, Wilkinson D, Palková Z. Global changes in gene expression associated with phenotypic switching of wild yeast. BMC Genomics 2014; 15:136. [PMID: 24533484 PMCID: PMC3930820 DOI: 10.1186/1471-2164-15-136] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 02/07/2014] [Indexed: 12/23/2022] Open
Abstract
Background Saccharomyces cerevisiae strains isolated from natural settings form structured biofilm colonies that are equipped with intricate protective mechanisms. These wild strains are able to reprogram themselves with a certain frequency during cultivation in plentiful laboratory conditions. The resulting domesticated strains switch off certain protective mechanisms and form smooth colonies that resemble those of common laboratory strains. Results Here, we show that domestication can be reversed when a domesticated strain is challenged by various adverse conditions; the resulting feral strain restores its ability to form structured biofilm colonies. Phenotypic, microscopic and transcriptomic analyses show that phenotypic transition is a complex process that affects various aspects of feral strain physiology; it leads to a phenotype that resembles the original wild strain in some aspects and the domesticated derivative in others. We specify the genetic determinants that are likely involved in the formation of a structured biofilm colonies. In addition to FLO11, these determinants include genes that affect the cell wall and membrane composition. We also identify changes occurring during phenotypic transitions that affect other properties of phenotypic strain-variants, such as resistance to the impact of environmental stress. Here we document the regulatory role of the histone deacetylase Hda1p in developing such a resistance. Conclusions We provide detailed analysis of transcriptomic and phenotypic modulations of three related S. cerevisiae strains that arose by phenotypic switching under diverse environmental conditions. We identify changes specifically related to a strain’s ability to create complex structured colonies; we also show that other changes, such as genome rearrangement(s), are unrelated to this ability. Finally, we identify the importance of histone deacetylase Hda1p in strain resistance to stresses.
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Affiliation(s)
| | | | | | | | - Zdena Palková
- Department of Genetics and Microbiology, Faculty of Science, Charles University in Prague, Viničná 5, 128 44 Prague 2, Czech Republic.
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Soll DR. The role of phenotypic switching in the basic biology and pathogenesis of Candida albicans. J Oral Microbiol 2014; 6:22993. [PMID: 24455104 PMCID: PMC3895265 DOI: 10.3402/jom.v6.22993] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Revised: 11/27/2013] [Accepted: 11/28/2013] [Indexed: 11/14/2022] Open
Abstract
The "white-opaque" transition in Candida albicans was discovered in 1987. For the next fifteen years, a significant body of knowledge accumulated that included differences between the cell types in gene expression, cellular architecture and virulence in cutaneous and systemic mouse models. However, it was not until 2002 that we began to understand the role of switching in the life history of this pathogen, the role of the mating type locus and the molecular pathways that regulated it. Then in 2006, both the master switch locus WORI and the pheromone-induced white cell biofilm were discovered. Since that year, a number of new observations on the regulation and biology of switching have been made that have significantly increased the perceived complexity of this fascinating phenotypic transition.
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Affiliation(s)
- David R Soll
- Developmental Studies Hybridoma Bank, Department of Biology and College of Dentistry, University of Iowa, Iowa City, IA, USA
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Connolly LA, Riccombeni A, Grózer Z, Holland LM, Lynch DB, Andes DR, Gácser A, Butler G. The APSES transcription factor Efg1 is a global regulator that controls morphogenesis and biofilm formation in Candida parapsilosis. Mol Microbiol 2013; 90:36-53. [PMID: 23895281 PMCID: PMC3912905 DOI: 10.1111/mmi.12345] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/24/2013] [Indexed: 11/30/2022]
Abstract
Efg1 (a member of the APSES family) is an important regulator of hyphal growth and of the white-to-opaque transition in Candida albicans and very closely related species. We show that in Candida parapsilosis Efg1 is a major regulator of a different morphological switch at the colony level, from a concentric to smooth morphology. The rate of switching is at least 20-fold increased in an efg1 knockout relative to wild type. Efg1 deletion strains also have reduced biofilm formation, attenuated virulence in an insect model, and increased sensitivity to SDS and caspofungin. Biofilm reduction is more dramatic in in vitro than in in vivo models. An Efg1 paralogue (Efh1) is restricted to Candida species, and does not regulate concentric-smooth phenotype switching, biofilm formation or stress response. We used ChIP-seq to identify the Efg1 regulon. A total of 931 promoter regions bound by Efg1 are highly enriched for transcription factors and regulatory proteins. Efg1 also binds to its own promoter, and negatively regulates its expression. Efg1 targets are enriched in binding sites for 93 additional transcription factors, including Ndt80. Our analysis suggests that Efg1 has an ancient role as regulator of development in fungi, and is central to several regulatory networks.
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Affiliation(s)
- Leona A Connolly
- School of Biomolecular and Biomedical Science Conway Institute, University College DublinBelfield, Dublin 4, Ireland
| | - Alessandro Riccombeni
- School of Biomolecular and Biomedical Science Conway Institute, University College DublinBelfield, Dublin 4, Ireland
| | - Zsuzsana Grózer
- Department of Microbiology, University of SzegedH-6726, Szeged Kozep fasor 52, Hungary
| | - Linda M Holland
- School of Biomolecular and Biomedical Science Conway Institute, University College DublinBelfield, Dublin 4, Ireland
| | - Denise B Lynch
- School of Biomolecular and Biomedical Science Conway Institute, University College DublinBelfield, Dublin 4, Ireland
| | - David R Andes
- Departments of Medicine and Microbiology and Immunology, University of WisconsinMadison, WI, USA
| | - Attila Gácser
- Department of Microbiology, University of SzegedH-6726, Szeged Kozep fasor 52, Hungary
| | - Geraldine Butler
- School of Biomolecular and Biomedical Science Conway Institute, University College DublinBelfield, Dublin 4, Ireland
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Ras signaling gets fine-tuned: regulation of multiple pathogenic traits of Candida albicans. EUKARYOTIC CELL 2013; 12:1316-25. [PMID: 23913542 DOI: 10.1128/ec.00094-13] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Candida albicans is an opportunistic fungal pathogen that can cause disseminated infection in patients with indwelling catheters or other implanted medical devices. A common resident of the human microbiome, C. albicans responds to environmental signals, such as cell contact with catheter materials and exposure to serum or CO2, by triggering the expression of a variety of traits, some of which are known to contribute to its pathogenic lifestyle. Such traits include adhesion, biofilm formation, filamentation, white-to-opaque (W-O) switching, and two recently described phenotypes, finger and tentacle formation. Under distinct sets of environmental conditions and in specific cell types (mating type-like a [MTLa]/alpha cells, MTL homozygotes, or daughter cells), C. albicans utilizes (or reutilizes) a single signal transduction pathway-the Ras pathway-to affect these phenotypes. Ras1, Cyr1, Tpk2, and Pde2, the proteins of the Ras signaling pathway, are the only nontranscriptional regulatory proteins that are known to be essential for regulating all of these processes. How does C. albicans utilize this one pathway to regulate all of these phenotypes? The regulation of distinct and yet related processes by a single, evolutionarily conserved pathway is accomplished through the use of downstream transcription factors that are active under specific environmental conditions and in different cell types. In this minireview, we discuss the role of Ras signaling pathway components and Ras pathway-regulated transcription factors as well as the transcriptional regulatory networks that fine-tune gene expression in diverse biological contexts to generate specific phenotypes that impact the virulence of C. albicans.
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Differential regulation of white-opaque switching by individual subunits of Candida albicans mediator. EUKARYOTIC CELL 2013; 12:1293-304. [PMID: 23873866 DOI: 10.1128/ec.00137-13] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The multisubunit eukaryotic Mediator complex integrates diverse positive and negative gene regulatory signals and transmits them to the core transcription machinery. Mutations in individual subunits within the complex can lead to decreased or increased transcription of certain subsets of genes, which are highly specific to the mutated subunit. Recent studies suggest a role for Mediator in epigenetic silencing. Using white-opaque morphological switching in Candida albicans as a model, we have shown that Mediator is required for the stability of both the epigenetic silenced (white) and active (opaque) states of the bistable transcription circuit driven by the master regulator Wor1. Individual deletions of eight C. albicans Mediator subunits have shown that different Mediator subunits have dramatically diverse effects on the directionality, frequency, and environmental induction of epigenetic switching. Among the Mediator deletion mutants analyzed, only Med12 has a steady-state transcriptional effect on the components of the Wor1 circuit that clearly corresponds to its effect on switching. The MED16 and MED9 genes have been found to be among a small subset of genes that are required for the stability of both the white and opaque states. Deletion of the Med3 subunit completely destabilizes the opaque state, even though the Wor1 transcription circuit is intact and can be driven by ectopic expression of Wor1. The highly impaired ability of the med3 deletion mutant to mate, even when Wor1 expression is ectopically induced, reveals that the activation of the Wor1 circuit can be decoupled from the opaque state and one of its primary biological consequences.
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Levy SF, Ziv N, Siegal ML. Bet hedging in yeast by heterogeneous, age-correlated expression of a stress protectant. PLoS Biol 2012; 10:e1001325. [PMID: 22589700 PMCID: PMC3348152 DOI: 10.1371/journal.pbio.1001325] [Citation(s) in RCA: 242] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Accepted: 03/26/2012] [Indexed: 01/06/2023] Open
Abstract
A new experimental approach reveals a bet-hedging strategy in unstressed, clonal yeast cells, whereby they adopt a range of growth states that correlate with expression of a trehalose-synthesis regulator and predict resistance to future stress. Genetically identical cells grown in the same culture display striking cell-to-cell heterogeneity in gene expression and other traits. A crucial challenge is to understand how much of this heterogeneity reflects the noise tolerance of a robust system and how much serves a biological function. In bacteria, stochastic gene expression results in cell-to-cell heterogeneity that might serve as a bet-hedging mechanism, allowing a few cells to survive through an antimicrobial treatment while others perish. Despite its clinical importance, the molecular mechanisms underlying bet hedging remain unclear. Here, we investigate the mechanisms of bet hedging in Saccharomyces cerevisiae using a new high-throughput microscopy assay that monitors variable protein expression, morphology, growth rate, and survival outcomes of tens of thousands of yeast microcolonies simultaneously. We find that clonal populations display broad distributions of growth rates and that slow growth predicts resistance to heat killing in a probabalistic manner. We identify several gene products that are likely to play a role in bet hedging and confirm that Tsl1, a trehalose-synthesis regulator, is an important component of this resistance. Tsl1 abundance correlates with growth rate and replicative age and predicts survival. Our results suggest that yeast bet hedging results from multiple epigenetic growth states determined by a combination of stochastic and deterministic factors. Genetically identical cells grown in the same environment can display heterogeneity in their morphology, behavior, and composition of their cellular components. In some microorganisms, such cellular heterogeneity can underlie a phenomenon known as bet hedging because it enables some cells to survive in harsh environments, hence increasing the overall population fitness when environmental shifts are unpredictable. Bet hedging is likely to be an important strategy by which microbes infect humans and evade antimicrobial treatments, yet little is known of how cellular heterogeneity contributes to microbial survival. Here, we study the mechanisms underlying bet hedging in yeast. We find that populations of genetically identical yeast contain a broad distribution of growth rates and that slow growth predicts resistance to heat killing in a graded fashion. We identify several gene products that are likely to play a role in this bet-hedging strategy and confirm that Tsl1, a regulator of the production of the disaccharide trehalose, is an important component of acute stress resistance. Finally, we find that old age in cells correlates with a Tsl1-abundant, stress-resistant cell state. Our results suggest that trehalose synthesis is part of a complex and multifactorial mechanism that underlies bet hedging in yeast.
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Affiliation(s)
- Sasha F. Levy
- Center for Genomics and Systems Biology, Department of Biology, New York University, New York, New York, United States of America
- * E-mail: (SFL); (MLS)
| | - Naomi Ziv
- Center for Genomics and Systems Biology, Department of Biology, New York University, New York, New York, United States of America
| | - Mark L. Siegal
- Center for Genomics and Systems Biology, Department of Biology, New York University, New York, New York, United States of America
- * E-mail: (SFL); (MLS)
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Abstract
The human commensal fungus Candida albicans can cause not only superficial infections, but also life-threatening disease in immunocompromised individuals. C. albicans can grow in several morphological forms. The ability to switch between different phenotypic forms has been thought to contribute to its virulence. The yeast-filamentous growth transition and white-opaque switching represent two typical morphological switching systems, which have been intensively studied in C. albicans. The interplay between environmental factors and genes determines the morphology of C. albicans. This review focuses on the regulation of phenotypic changes in this pathogenic organism by external environmental cues and internal genes.
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Affiliation(s)
- Guanghua Huang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences Beijing, China.
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40
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Lopes da Rosa J, Kaufman PD. Chromatin-mediated Candida albicans virulence. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1819:349-55. [PMID: 21888998 PMCID: PMC3243783 DOI: 10.1016/j.bbagrm.2011.08.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2011] [Revised: 08/13/2011] [Accepted: 08/16/2011] [Indexed: 10/17/2022]
Abstract
Candida albicans is the most prevalent human fungal pathogen. To successfully propagate an infection, this organism relies on the ability to change morphology, express virulence-associated genes and resist DNA damage caused by the host immune system. Many of these events involve chromatin alterations that are crucial for virulence. This review will focus on the studies that have been conducted on how chromatin function affects pathogenicity of C. albicans and other fungi. This article is part of a Special Issue entitled: Histone chaperones and Chromatin assembly.
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Affiliation(s)
- Jessica Lopes da Rosa
- Program in Gene Function and Expression, University of Massachusetts Medical School, Worcester, MA 01605-2324, USA
| | - Paul D. Kaufman
- Program in Gene Function and Expression, University of Massachusetts Medical School, Worcester, MA 01605-2324, USA
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Posttranslational modifications of proteins in the pathobiology of medically relevant fungi. EUKARYOTIC CELL 2011; 11:98-108. [PMID: 22158711 DOI: 10.1128/ec.05238-11] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Posttranslational modifications of proteins drive a wide variety of cellular processes in eukaryotes, regulating cell growth and division as well as adaptive and developmental processes. With regard to the fungal kingdom, most information about posttranslational modifications has been generated through studies of the model yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe, where, for example, the roles of protein phosphorylation, glycosylation, acetylation, ubiquitination, sumoylation, and neddylation have been dissected. More recently, information has begun to emerge for the medically important fungal pathogens Candida albicans, Aspergillus fumigatus, and Cryptococcus neoformans, highlighting the relevance of posttranslational modifications for virulence. We review the available literature on protein modifications in fungal pathogens, focusing in particular upon the reversible peptide modifications sumoylation, ubiquitination, and neddylation.
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Lu Y, Su C, Wang A, Liu H. Hyphal development in Candida albicans requires two temporally linked changes in promoter chromatin for initiation and maintenance. PLoS Biol 2011; 9:e1001105. [PMID: 21811397 PMCID: PMC3139633 DOI: 10.1371/journal.pbio.1001105] [Citation(s) in RCA: 128] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Accepted: 05/31/2011] [Indexed: 12/21/2022] Open
Abstract
Phenotypic plasticity is common in development. For Candida albicans, the most common cause of invasive fungal infections in humans, morphological plasticity is its defining feature and is critical for its pathogenesis. Unlike other fungal pathogens that exist primarily in either yeast or hyphal forms, C. albicans is able to switch reversibly between yeast and hyphal growth forms in response to environmental cues. Although many regulators have been found involved in hyphal development, the mechanisms of regulating hyphal development and plasticity of dimorphism remain unclear. Here we show that hyphal development involves two sequential regulations of the promoter chromatin of hypha-specific genes. Initiation requires a rapid but temporary disappearance of the Nrg1 transcriptional repressor of hyphal morphogenesis via activation of the cAMP-PKA pathway. Maintenance requires promoter recruitment of Hda1 histone deacetylase under reduced Tor1 (target of rapamycin) signaling. Hda1 deacetylates a subunit of the NuA4 histone acetyltransferase module, leading to eviction of the NuA4 acetyltransferase module and blockage of Nrg1 access to promoters of hypha-specific genes. Promoter recruitment of Hda1 for hyphal maintenance happens only during the period when Nrg1 is gone. The sequential regulation of hyphal development by the activation of the cAMP-PKA pathway and reduced Tor1 signaling provides a molecular mechanism for plasticity of dimorphism and how C. albicans adapts to the varied host environments in pathogenesis. Such temporally linked regulation of promoter chromatin by different signaling pathways provides a unique mechanism for integrating multiple signals during development and cell fate specification. Many organisms are able to change their phenotype in response to changes in the environment, a phenomenon referred to as plasticity. Candida albicans, a major opportunistic fungal pathogen of humans, can undergo reversible morphological changes between yeast (spherical) and hyphal (filamentous) forms of growth in response to environmental cues. This morphological plasticity is essential for its pathogenesis and survival in its hosts. In this study, we show that hyphal development is initiated and maintained by two major nutrient-sensing cellular growth pathways that act by removing the inhibition provided by the transcriptional repressor Nrg1. While initiation requires a rapid but temporary disappearance of Nrg1 via activation of the cAMP-dependent protein kinase A pathway, maintenance requires the recruitment to promoters of the Hda1 histone deacetylase under conditions of reduced signaling by the target of rapamycin (TOR) kinase, leading to chromatin remodeling that blocks Nrg1 access to the promoters of hypha-specific genes. We observed that recruitment of Hda1 to promoters happens only during the time window when Nrg1 is absent. Such temporally linked regulation of promoter chromatin by different signaling pathways provides a unique mechanism for integrating multiple signals in the regulation of gene expression and phenotypic plasticity during development and cell fate specification.
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Affiliation(s)
- Yang Lu
- Department of Biological Chemistry, University of California, Irvine, California, United States of America
| | - Chang Su
- Department of Biological Chemistry, University of California, Irvine, California, United States of America
| | - Allen Wang
- Department of Biological Chemistry, University of California, Irvine, California, United States of America
| | - Haoping Liu
- Department of Biological Chemistry, University of California, Irvine, California, United States of America
- * E-mail:
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Stevenson JS, Liu H. Regulation of white and opaque cell-type formation in Candida albicans by Rtt109 and Hst3. Mol Microbiol 2011; 81:1078-91. [PMID: 21749487 DOI: 10.1111/j.1365-2958.2011.07754.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
How different cell types with the same genotype are formed and heritability maintained is a fundamental question in biology. We utilized white-opaque switching in Candida albicans as a system to study mechanisms of cell-type formation and maintenance. Each cell type has tractable characters, which are maintained over many cell divisions. Cell-type specification is under the control of interlocking transcriptional feedback loops, with Wor1 being the master regulator of the opaque cell type. Here we show that deletion of RTT109, encoding the acetyltransferase for histone H3K56, impairs stochastic and environmentally stimulated white-opaque switching. Ectopic expression of WOR1 mostly bypasses the requirement for RTT109, but opaque cells lacking RTT109 cannot be maintained. We have also discovered that nicotinamide induces opaque cell formation, and this activity of nicotinamide requires RTT109. Reducing the copy number of HST3, which encodes the H3K56 deacetylase, also leads to increased opaque formation. We further show that the Hst3 level is downregulated in the presence of genotoxins and ectopic expression of HST3 blocks genotoxin induced switching. This finding links genotoxin induced switching to Hst3 regulation. Together, these findings suggest RTT109 and HST3 genes play an important role in the regulation of white-opaque switching in C. albicans.
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Affiliation(s)
- John S Stevenson
- Department of Biological Chemistry, University of California, Irvine, CA 92697, USA
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Chen SCA, Lewis RE, Kontoyiannis DP. Direct effects of non-antifungal agents used in cancer chemotherapy and organ transplantation on the development and virulence of Candida and Aspergillus species. Virulence 2011; 2:280-95. [PMID: 21701255 PMCID: PMC3173675 DOI: 10.4161/viru.2.4.16764] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2011] [Revised: 06/01/2011] [Accepted: 06/03/2011] [Indexed: 11/19/2022] Open
Abstract
Conventional antineoplastic, novel immunosuppressive agents and antibiotics used in cancer treatment can directly affect the growth, development and virulence of Candida and Aspergillus species. Cytotoxic and cisplatin compounds have anti-Candida activity and may be synergistic with antifungal drugs; they also inhibit Candida and Aspergillus filamentation/conidation and effect increased virulence in vitro. Glucocorticoids enhance Candida adherence to epithelial cells, germination in serum and in vitro secretion of phospholipases and proteases, as well as growth of A. fumigatus. Calcineurin and target of rapamycin inhibitors perturb Candida and Aspergillus morphogenesis, stress responses and survival in serum, reduce azole tolerance in Candida, but yield conflicting in vivo data. Inhibition of candidal heat shock protein 90 and candidal-specific histone deacetylase represent feasible therapeutic approaches for candidiasis. Tyrosine kinase inhibitors inhibit fungal cell entry into epithelial cells and phagocytosis. Quinolone and other antibiotics may augment activity of azole and polyene agents. The correlation of in vitro effects with clinically meaningful in vivo systems is warranted.
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Affiliation(s)
- Sharon C-A Chen
- Centre for Infectious Diseases and Microbiology, Westmead Hospital, University of Sydney, Westmead, NSW Australia
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Zacchi LF, Schulz WL, Davis DA. HOS2 and HDA1 encode histone deacetylases with opposing roles in Candida albicans morphogenesis. PLoS One 2010; 5:e12171. [PMID: 20730094 PMCID: PMC2921335 DOI: 10.1371/journal.pone.0012171] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2010] [Accepted: 07/14/2010] [Indexed: 11/18/2022] Open
Abstract
Epigenetic mechanisms regulate the expression of virulence traits in diverse pathogens, including protozoan and fungi. In the human fungal pathogen Candida albicans, virulence traits such as antifungal resistance, white-opaque switching, and adhesion to lung cells are regulated by histone deacetylases (HDACs). However, the role of HDACs in the regulation of the yeast-hyphal morphogenetic transitions, a critical virulence attribute of C. albicans, remains poorly explored. In this study, we wished to determine the relevance of other HDACs on C. albicans morphogenesis. We generated mutants in the HDACs HOS1, HOS2, RPD31, and HDA1 and determined their ability to filament in response to different environmental stimuli. We found that while HOS1 and RPD31 have no or a more limited role in morphogenesis, the HDACs HOS2 and HDA1 have opposite roles in the regulation of hyphal formation. Our results demonstrate an important role for HDACs on the regulation of yeast-hyphal transitions in the human pathogen C. albicans.
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Affiliation(s)
- Lucia F Zacchi
- Department of Microbiology, University of Minnesota, Minneapolis, Minnesota, USA.
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Zacchi LF, Selmecki AM, Berman J, Davis DA. Low dosage of histone H4 leads to growth defects and morphological changes in Candida albicans. PLoS One 2010; 5:e10629. [PMID: 20498713 PMCID: PMC2869362 DOI: 10.1371/journal.pone.0010629] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2010] [Accepted: 04/14/2010] [Indexed: 11/18/2022] Open
Abstract
Chromatin function depends on adequate histone stoichiometry. Alterations in histone dosage affect transcription and chromosome segregation, leading to growth defects and aneuploidies. In the fungal pathogen Candida albicans, aneuploidy formation is associated with antifungal resistance and pathogenesis. Histone modifying enzymes and chromatin remodeling proteins are also required for pathogenesis. However, little is known about the mechanisms that generate aneuploidies or about the epigenetic mechanisms that shape the response of C. albicans to the host environment. Here, we determined the impact of histone H4 deficit in the growth and colony morphology of C. albicans. We found that C. albicans requires at least two of the four alleles that code for histone H4 (HHF1 and HHF22) to grow normally. Strains with only one histone H4 allele show a severe growth defect and unstable colony morphology, and produce faster-growing, morphologically stable suppressors. Segmental or whole chromosomal trisomies that increased wild-type histone H4 copy number were the preferred mechanism of suppression. This is the first study of a core nucleosomal histone in C. albicans, and constitutes the prelude to future, more detailed research on the function of histone H4 in this important fungal pathogen.
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Affiliation(s)
- Lucia F. Zacchi
- Department of Microbiology, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Anna M. Selmecki
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Judith Berman
- Department of Microbiology, University of Minnesota, Minneapolis, Minnesota, United States of America
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Dana A. Davis
- Department of Microbiology, University of Minnesota, Minneapolis, Minnesota, United States of America
- * E-mail:
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Morschhäuser J. Regulation of white-opaque switching in Candida albicans. Med Microbiol Immunol 2010; 199:165-72. [DOI: 10.1007/s00430-010-0147-0] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2010] [Indexed: 01/14/2023]
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Huang G, Yi S, Sahni N, Daniels KJ, Srikantha T, Soll DR. N-acetylglucosamine induces white to opaque switching, a mating prerequisite in Candida albicans. PLoS Pathog 2010; 6:e1000806. [PMID: 20300604 PMCID: PMC2837409 DOI: 10.1371/journal.ppat.1000806] [Citation(s) in RCA: 161] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Accepted: 02/03/2010] [Indexed: 11/18/2022] Open
Abstract
To mate, the fungal pathogen Candida albicans must undergo homozygosis at the mating-type locus and then switch from the white to opaque phenotype. Paradoxically, opaque cells were found to be unstable at physiological temperature, suggesting that mating had little chance of occurring in the host, the main niche of C. albicans. Recently, however, it was demonstrated that high levels of CO(2), equivalent to those found in the host gastrointestinal tract and select tissues, induced the white to opaque switch at physiological temperature, providing a possible resolution to the paradox. Here, we demonstrate that a second signal, N-acetylglucosamine (GlcNAc), a monosaccharide produced primarily by gastrointestinal tract bacteria, also serves as a potent inducer of white to opaque switching and functions primarily through the Ras1/cAMP pathway and phosphorylated Wor1, the gene product of the master switch locus. Our results therefore suggest that signals produced by bacterial co-members of the gastrointestinal tract microbiota regulate switching and therefore mating of C. albicans.
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Affiliation(s)
- Guanghua Huang
- Department of Biology, The University of Iowa, Iowa City, Iowa, United States of America
| | - Song Yi
- Department of Biology, The University of Iowa, Iowa City, Iowa, United States of America
| | - Nidhi Sahni
- Department of Biology, The University of Iowa, Iowa City, Iowa, United States of America
| | - Karla J. Daniels
- Department of Biology, The University of Iowa, Iowa City, Iowa, United States of America
| | - Thyagarajan Srikantha
- Department of Biology, The University of Iowa, Iowa City, Iowa, United States of America
| | - David R. Soll
- Department of Biology, The University of Iowa, Iowa City, Iowa, United States of America
- * E-mail:
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Tribus M, Bauer I, Galehr J, Rieser G, Trojer P, Brosch G, Loidl P, Haas H, Graessle S. A novel motif in fungal class 1 histone deacetylases is essential for growth and development of Aspergillus. Mol Biol Cell 2009; 21:345-53. [PMID: 19940017 PMCID: PMC2808227 DOI: 10.1091/mbc.e09-08-0750] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Acetylation of the N-terminal tails of core histones is an important regulatory mechanism in eukaryotic organisms. In filamentous fungi, little is known about the enzymes that modify histone tails. However, it is increasingly evident that histone deacetylases and histone acetyltransferases are critical factors for the regulation of genes involved in fungal pathogenicity, stress response, and production of secondary metabolites such as antibiotics or fungal toxins. Here, we show that depletion of RpdA, an RPD3-type histone deacetylase of Aspergillus nidulans, leads to a pronounced reduction of growth and sporulation of the fungus. We demonstrate that a so far unnoticed motif in the C terminus of fungal RpdA histone deacetylases is required for the catalytic activity of the enzyme and consequently is essential for the viability of A. nidulans. Moreover, we provide evidence that this motif is also crucial for the survival of other, if not all, filamentous fungi, including pathogens such as Aspergillus fumigatus or Cochliobolus carbonum. Thus, the extended C terminus of RpdA-type enzymes represents a promising target for fungal-specific histone deacetylase-inhibitors that may have potential as novel antifungal compounds with medical and agricultural applications.
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Affiliation(s)
- Martin Tribus
- Division of Molecular Biology, Biocenter, Innsbruck Medical University, A-6020 Innsbruck, Austria
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Al-Dhaheri RS, Douglas LJ. Apoptosis in Candida biofilms exposed to amphotericin B. J Med Microbiol 2009; 59:149-157. [PMID: 19892857 DOI: 10.1099/jmm.0.015784-0] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Candida biofilms are resistant to a range of antifungal agents in current clinical use. The basis of this drug resistance is not clear, but in some cases it could be due to the presence of a small number of drug-tolerant or persister cells. In this study, specific staining methods were used to investigate the existence of persisters and apoptosis in Candida biofilms subjected to different concentrations of amphotericin B. Fluorescein diacetate staining revealed the presence of persisters in biofilms of one of two strains of Candida albicans tested, and in biofilms of Candida krusei and Candida parapsilosis. Caspase activity, indicative of apoptosis, was detected with SR-FLICA and (aspartyl)(2)-rhodamine 110 fluorochrome-based staining reagents in all of these biofilms. The general inhibitor of mammalian caspases, Z-VAD-FMK, when used at a low concentration (2.5 microM), increased the viability of drug-treated biofilms up to 11.5-fold (P <0.001 %). Seven specific caspase inhibitors had different effects on C. albicans biofilm viability, but inhibitors of caspases-1, -9, -5, -3 and -2 all significantly increased cell survival (40-fold, 8-fold, 3.5-fold, 1.9-fold and 1.7-fold, respectively). However, histone deacetylase (HDA) inhibitors enhanced the activity of amphotericin B for biofilms of all three Candida species. Sodium butyrate and sodium valproate, for example, when added concurrently with amphotericin B, completely eliminated biofilm populations of C. albicans. Overall, our results demonstrate an apoptotic process in amphotericin-treated biofilms of three Candida species. They also indicate that HDA inhibitors can enhance the action of the drug and in some cases even eradicate persister subpopulations, suggesting that histone acetylation might activate apoptosis in these cells.
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Affiliation(s)
- Rawya S Al-Dhaheri
- Division of Infection and Immunity, Faculty of Biomedical and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - L Julia Douglas
- Division of Infection and Immunity, Faculty of Biomedical and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
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