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Zhang ZH, Sun LL, Fu BQ, Deng J, Jia CL, Miao MX, Yang F, Cao YB, Yan TH. Aneuploidy underlies brefeldin A-induced antifungal drug resistance in Cryptococcus neoformans. Front Cell Infect Microbiol 2024; 14:1397724. [PMID: 38966251 PMCID: PMC11222406 DOI: 10.3389/fcimb.2024.1397724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Accepted: 05/17/2024] [Indexed: 07/06/2024] Open
Abstract
Cryptococcus neoformans is at the top of the list of "most wanted" human pathogens. Only three classes of antifungal drugs are available for the treatment of cryptococcosis. Studies on antifungal resistance mechanisms are limited to the investigation of how a particular antifungal drug induces resistance to a particular drug, and the impact of stresses other than antifungals on the development of antifungal resistance and even cross-resistance is largely unexplored. The endoplasmic reticulum (ER) is a ubiquitous subcellular organelle of eukaryotic cells. Brefeldin A (BFA) is a widely used chemical inducer of ER stress. Here, we found that both weak and strong selection by BFA caused aneuploidy formation in C. neoformans, mainly disomy of chromosome 1, chromosome 3, and chromosome 7. Disomy of chromosome 1 conferred cross-resistance to two classes of antifungal drugs: fluconazole and 5-flucytosine, as well as hypersensitivity to amphotericin B. However, drug resistance was unstable, due to the intrinsic instability of aneuploidy. We found overexpression of AFR1 on Chr1 and GEA2 on Chr3 phenocopied BFA resistance conferred by chromosome disomy. Overexpression of AFR1 also caused resistance to fluconazole and hypersensitivity to amphotericin B. Furthermore, a strain with a deletion of AFR1 failed to form chromosome 1 disomy upon BFA treatment. Transcriptome analysis indicated that chromosome 1 disomy simultaneously upregulated AFR1, ERG11, and other efflux and ERG genes. Thus, we posit that BFA has the potential to drive the rapid development of drug resistance and even cross-resistance in C. neoformans, with genome plasticity as the accomplice.
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Affiliation(s)
- Zhi-hui Zhang
- Institute of Vascular Disease, Shanghai TCM-Integrated Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Liu-liu Sun
- Department of Pharmacy, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, China
| | - Bu-qing Fu
- Laboratory Department, Jiangsu Province Hospital of Chinese Medicine, Nanjing, China
| | - Jie Deng
- Institute of Vascular Disease, Shanghai TCM-Integrated Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Cheng-lin Jia
- Institute of Vascular Disease, Shanghai TCM-Integrated Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Ming-xing Miao
- Department of Physiology and Pharmacology, School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Feng Yang
- Institute of Vascular Disease, Shanghai TCM-Integrated Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
- Department of Pharmacy, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, China
| | - Yong-bing Cao
- Institute of Vascular Disease, Shanghai TCM-Integrated Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Tian-hua Yan
- Department of Physiology and Pharmacology, School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, China
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Unique roles of aminophospholipid translocase Drs2p in governing efflux pump activity, ergosterol level, virulence traits, and host-pathogen interaction in Candida albicans. INTERNATIONAL MICROBIOLOGY : THE OFFICIAL JOURNAL OF THE SPANISH SOCIETY FOR MICROBIOLOGY 2022; 25:769-779. [PMID: 35788922 DOI: 10.1007/s10123-022-00262-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 06/03/2022] [Accepted: 06/22/2022] [Indexed: 10/17/2022]
Abstract
Infections caused by Candida albicans are rising due to increment in drug resistance and a limited arsenal of conventional antifungal drugs. Thus, elucidating the novel antifungal targets still represent an alternative that could overcome the problem of multidrug resistance (MDR). In this study, we have uncovered the distinctive effect of aminophospholipid translocase (Drs2p) deletion on major MDR mechanisms of C. albicans. We determined that efflux activity was diminished in Δdrs2 mutant as revealed by extracellular rhodamine 6G (R6G) efflux and flow cytometry. Moreover, we further unveiled that Δdrs2 mutant displayed decreased ergosterol content and increased membrane fluidity. Furthermore, Drs2p deletion affects the virulence attributes and led to inhibited hyphal growth and reduced biofilm formation. Additionally, THP-1 cell lines' mediated host-pathogen interaction studies revealed that Δdrs2 mutant displayed enhanced phagocytosis and altered cytokine production leading to increased IL-6 and decreased IL-10 production. Taken together, the present study demonstrates the relevance of Drs2p in C. albicans and consequently disrupting pathways known for mediating drug resistance and immune recognition. Comprehensive studies are further required to authenticate Drs2p as a novel antifungal drug target.
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Shahi G, Kumar M, Khandelwal NK, Banerjee A, Sarkar P, Kumari S, Esquivel BD, Chauhan N, Chattopadhyay A, White TC, Gaur NA, Singh A, Prasad R. Inositol Phosphoryl Transferase, Ipt1, Is a Critical Determinant of Azole Resistance and Virulence Phenotypes in Candida glabrata. J Fungi (Basel) 2022; 8:jof8070651. [PMID: 35887407 PMCID: PMC9322651 DOI: 10.3390/jof8070651] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 06/17/2022] [Accepted: 06/18/2022] [Indexed: 12/10/2022] Open
Abstract
In this study, we have specifically blocked a key step of sphingolipid (SL) biosynthesis in Candida glabrata by disruption of the orthologs of ScIpt1 and ScSkn1. Based on their close homology with S. cerevisiae counterparts, the proteins are predicted to catalyze the addition of a phosphorylinositol group onto mannosyl inositolphosphoryl ceramide (MIPC) to form mannosyl diinositolphosphoryl ceramide (M(IP)2C), which accounts for the majority of complex SL structures in S. cerevisiae membranes. High throughput lipidome analysis confirmed the accumulation of MIPC structures in ΔCgipt1 and ΔCgskn1 cells, albeit to lesser extent in the latter. Noticeably, ΔCgipt1 cells showed an increased susceptibility to azoles; however, ΔCgskn1 cells showed no significant changes in the drug susceptibility profiles. Interestingly, the azole susceptible phenotype of ΔCgipt1 cells seems to be independent of the ergosterol content. ΔCgipt1 cells displayed altered lipid homeostasis, increased membrane fluidity as well as high diffusion of radiolabeled fluconazole (3H-FLC), which could together influence the azole susceptibility of C. glabrata. Furthermore, in vivo experiments also confirmed compromised virulence of the ΔCgipt1 strain. Contrarily, specific functions of CgSkn1 remain unclear.
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Affiliation(s)
- Garima Shahi
- Amity Institute of Biotechnology and Integrative Science and Health, Amity University Gurgaon, Gurgaon 122412, India; (G.S.); (M.K.); (A.B.)
| | - Mohit Kumar
- Amity Institute of Biotechnology and Integrative Science and Health, Amity University Gurgaon, Gurgaon 122412, India; (G.S.); (M.K.); (A.B.)
- Yeast Biofuel Group, International Centre for Genetic Engineering and Biotechnology, New Delhi 110067, India; (S.K.); (N.A.G.)
| | | | - Atanu Banerjee
- Amity Institute of Biotechnology and Integrative Science and Health, Amity University Gurgaon, Gurgaon 122412, India; (G.S.); (M.K.); (A.B.)
| | - Parijat Sarkar
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500007, India; (P.S.); (A.C.)
| | - Sonam Kumari
- Yeast Biofuel Group, International Centre for Genetic Engineering and Biotechnology, New Delhi 110067, India; (S.K.); (N.A.G.)
| | - Brooke D. Esquivel
- School of Biological and Chemical Sciences, University of Missouri at Kansas City, Kansas City, MO 64110, USA; (B.D.E.); (T.C.W.)
| | - Neeraj Chauhan
- Department of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA;
| | - Amitabha Chattopadhyay
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500007, India; (P.S.); (A.C.)
| | - Theodore C. White
- School of Biological and Chemical Sciences, University of Missouri at Kansas City, Kansas City, MO 64110, USA; (B.D.E.); (T.C.W.)
| | - Naseem A. Gaur
- Yeast Biofuel Group, International Centre for Genetic Engineering and Biotechnology, New Delhi 110067, India; (S.K.); (N.A.G.)
| | - Ashutosh Singh
- Department of Biochemistry, University of Lucknow, Lucknow 226007, India
- Correspondence: (A.S.); (R.P.)
| | - Rajendra Prasad
- Amity Institute of Biotechnology and Integrative Science and Health, Amity University Gurgaon, Gurgaon 122412, India; (G.S.); (M.K.); (A.B.)
- Correspondence: (A.S.); (R.P.)
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Hans S, Fatima Z, Hameed S. Mass spectrometry-based untargeted lipidomics reveals new compositional insights into membrane dynamics of Candida albicans under magnesium deprivation. J Appl Microbiol 2021; 132:978-993. [PMID: 34424599 DOI: 10.1111/jam.15265] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 06/16/2021] [Accepted: 08/18/2021] [Indexed: 11/29/2022]
Abstract
AIMS There is growing appreciation in adopting new approaches to disrupt multidrug resistance in human fungal pathogen, Candida albicans. The plasma membrane of C. albicans comprises potential lipid moieties that contribute towards the survival of pathogen and could be utilized as antifungal targets. Considering promising applications of developments in mass spectrometry (MS)-based lipidomics technology, the aim of the study was to analyse lipidome profile and expose lipid-dependent changes in response to Mg deprivation. METHODS AND RESULTS We found that both phosphatidylcholine (PC) and lysophosphatidylcholine (LysoPC) were decreased. Increased flip (inward translocation) in the fluorophore labelled NBD-PC was ascribed to enhanced PC-specific flippase activity. Furthermore, a decrease in phosphatidylethanolamine (PE) leading to altered membrane fluidity and loss of cellular material was prominent. Additionally, we observed decreased phosphatidylglycerol (PG) and phosphatidylinositol (PI) leading to genotoxic stress. Besides, we could detect enhanced levels of phosphatidylserine (PS), diacylglycerol (DAG) and triacylglycerides (TAG). The altered gene expressions of lipid biosynthetic pathway by RT-PCR correlated with the lipidome profile. Lastly, we explored abrogated ionic (Na+ and K+ ) transport across the plasma membrane. CONCLUSIONS We propose that C. albicans exposed to Mg deprivation could reorganize plasma membrane (lipid species, membrane fluidity and ionic transport), and possibly redirected carbon flux to store energy in TAGs as an adaptive stress response. This work unravels several vulnerable targets governing lipid metabolism in C. albicans and pave way for better antifungal strategies. SIGNIFICANCE AND IMPACT OF THE STUDY This study demonstrates that magnesium availability is important when one considers dissecting drug resistance mechanisms in Candida albicans. Through mass spectrometry (MS)-based lipidomics technology, the study analyses lipidome profile and exposes lipid-dependent changes that are vulnerable to magnesium availability and presents an opportunity to employ this new information in improving treatment strategies.
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Affiliation(s)
- Sandeep Hans
- Amity Institute of Biotechnology, Amity University Haryana, Manesar, Gurugram, India
| | - Zeeshan Fatima
- Amity Institute of Biotechnology, Amity University Haryana, Manesar, Gurugram, India
| | - Saif Hameed
- Amity Institute of Biotechnology, Amity University Haryana, Manesar, Gurugram, India
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Effects of Complex Electromagnetic Fields on Candida albicans Adhesion and Proliferation on Polyacrylic Resin. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11156786] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
(1) Background: The objectives of this study were to evaluate the effect of several sessions of the antibacterial protocol of complex electromagnetic fields (CMFs) on planktonic Candida albicans and fungal ability, after treatment with CMFs, to adhere and proliferate on acrylic resin materials. (2) Methods: Planktonic overnight cultures of Candida albicans were subjected to different entities of CMFs treatments. Four test groups were compared: “p1”: treated only with the first program of the antibacterial protocol; “p1–p5” subjected to the first five programs; “1 antibacterial” received one complete session of the protocol and “2 antibacterial” received two complete sessions. After the treatments, the number of colony forming units (CFUs) were recorded. Then, C. albicans broth cultures were cultivated on polyacrylic resin discs and evaluated for CFUs and subjected to scanning electron microscope (SEM) analysis. (3) Results: Microbiological analysis showed that CMFs promoted a significant reduction of C. albicans CFUs when the protocol “p1–p5” was applied. No statistically significant differences between test groups were observed if the time of exposure to CMFs was increased. SEM observations and CFUs showed that CMFs treatments have the ability to reduce C. albicans adherence and proliferation on discs. (4) Conclusions: The CMFs showed an antifungal effect as well as a decrease in C. albicans adhesion on polyacrylic resin.
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Lu H, Shrivastava M, Whiteway M, Jiang Y. Candida albicans targets that potentially synergize with fluconazole. Crit Rev Microbiol 2021; 47:323-337. [PMID: 33587857 DOI: 10.1080/1040841x.2021.1884641] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Fluconazole has characteristics that make it widely used in the clinical treatment of C. albicans infections. However, fluconazole has only a fungistatic activity in C. albicans, therefore, in the long-term treatment of C. albicans infection with fluconazole, C. albicans has the potential to acquire fluconazole resistance. A promising approach to increase fluconazole's efficacy is identifying potential targets of drugs that can enhance the antifungal effect of fluconazole, or even make the drug fungicidal. In this review, we systematically provide a global overview of potential targets of drugs synergistic with fluconazole in C. albicans, identify new avenues for research on fluconazole potentiation, and highlight the promise of combinatorial strategies with fluconazole in combatting C. albicans infections.
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Affiliation(s)
- Hui Lu
- Department of Pharmacology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | | | - Malcolm Whiteway
- Department of Biology, Concordia University, Montreal, QC, Canada
| | - Yuanying Jiang
- Department of Pharmacology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
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7
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Santos-Pereira C, Andrés MT, Chaves SR, Fierro JF, Gerós H, Manon S, Rodrigues LR, Côrte-Real M. Lactoferrin perturbs lipid rafts and requires integrity of Pma1p-lipid rafts association to exert its antifungal activity against Saccharomyces cerevisiae. Int J Biol Macromol 2021; 171:343-357. [PMID: 33421469 DOI: 10.1016/j.ijbiomac.2020.12.224] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 12/30/2020] [Accepted: 12/31/2020] [Indexed: 02/06/2023]
Abstract
Lactoferrin (Lf) is a bioactive milk-derived protein with remarkable wide-spectrum antifungal activity. To deepen our understanding of the molecular mechanisms underlying Lf cytotoxicity, the role of plasma membrane ergosterol- and sphingolipid-rich lipid rafts and their association with the proton pump Pma1p was explored. Pma1p was previously identified as a Lf-binding protein. Results showed that bovine Lf (bLf) perturbs ergosterol-rich lipid rafts organization by inducing intracellular accumulation of ergosterol. Using yeast mutant strains lacking lipid rafts-associated proteins or enzymes involved in the synthesis of ergosterol and sphingolipids, we found that perturbations in the composition of these membrane domains increase resistance to bLf-induced yeast cell death. Also, when Pma1p-lipid rafts association is compromised in the Pma1-10 mutant and in the absence of the Pma1p-binding protein Ast1p, the bLf killing activity is impaired. Altogether, results showed that the perturbation of lipid rafts and the inhibition of both Pma1p and V-ATPase activities mediate the antifungal activity of bLf. Since it is suggested that the combination of conventional antifungals with lipid rafts-disrupting compounds is a powerful antifungal approach, our data will help to pave the way for the use of bLf alone or in combination for the treatment/eradication of clinically and agronomically relevant yeast pathogens/fungi.
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Affiliation(s)
- Cátia Santos-Pereira
- Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho, 4710-057 Braga, Portugal; Centre of Biological Engineering (CEB), Department of Biological Engineering, University of Minho, 4710-057 Braga, Portugal
| | - María T Andrés
- Laboratory of Oral Microbiology, University Clinic of Dentistry (CLUO) and Department of Functional Biology (Microbiology), Faculty of Medicine, University of Oviedo, 33006 Oviedo, Asturias, Spain
| | - Susana R Chaves
- Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho, 4710-057 Braga, Portugal
| | - José F Fierro
- Laboratory of Oral Microbiology, University Clinic of Dentistry (CLUO) and Department of Functional Biology (Microbiology), Faculty of Medicine, University of Oviedo, 33006 Oviedo, Asturias, Spain
| | - Hernâni Gerós
- Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho, 4710-057 Braga, Portugal
| | - Stéphen Manon
- Institut de Biochimie et de Génétique Cellulaires, UMR5095, CNRS et Université de Bordeaux, CS61390, 1 Rue Camille Saint-Saëns, 33000 Bordeaux, France
| | - Lígia R Rodrigues
- Centre of Biological Engineering (CEB), Department of Biological Engineering, University of Minho, 4710-057 Braga, Portugal
| | - Manuela Côrte-Real
- Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho, 4710-057 Braga, Portugal.
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Fernández de Ullivarri M, Arbulu S, Garcia-Gutierrez E, Cotter PD. Antifungal Peptides as Therapeutic Agents. Front Cell Infect Microbiol 2020; 10:105. [PMID: 32257965 PMCID: PMC7089922 DOI: 10.3389/fcimb.2020.00105] [Citation(s) in RCA: 115] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 02/27/2020] [Indexed: 12/17/2022] Open
Abstract
Fungi have been used since ancient times in food and beverage-making processes and, more recently, have been harnessed for the production of antibiotics and in processes of relevance to the bioeconomy. Moreover, they are starting to gain attention as a key component of the human microbiome. However, fungi are also responsible for human infections. The incidence of community-acquired and nosocomial fungal infections has increased considerably in recent decades. Antibiotic resistance development, the increasing number of immunodeficiency- and/or immunosuppression-related diseases and limited therapeutic options available are triggering the search for novel alternatives. These new antifungals should be less toxic for the host, with targeted or broader antimicrobial spectra (for diseases of known and unknown etiology, respectively) and modes of actions that limit the potential for the emergence of resistance among pathogenic fungi. Given these criteria, antimicrobial peptides with antifungal properties, i.e., antifungal peptides (AFPs), have emerged as powerful candidates due to their efficacy and high selectivity. In this review, we provide an overview of the bioactivity and classification of AFPs (natural and synthetic) as well as their mode of action and advantages over current antifungal drugs. Additionally, natural, heterologous and synthetic production of AFPs with a view to greater levels of exploitation is discussed. Finally, we evaluate the current and potential applications of these peptides, along with the future challenges relating to antifungal treatments.
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Affiliation(s)
- Miguel Fernández de Ullivarri
- APC Microbiome Ireland, University College Cork, Cork, Ireland.,Food Bioscience Department, Teagasc Food Research Centre, Fermoy, Ireland
| | - Sara Arbulu
- APC Microbiome Ireland, University College Cork, Cork, Ireland.,Food Bioscience Department, Teagasc Food Research Centre, Fermoy, Ireland
| | - Enriqueta Garcia-Gutierrez
- Food Bioscience Department, Teagasc Food Research Centre, Fermoy, Ireland.,Gut Microbes and Health, Quadram Institute Bioscience, Norwich, United Kingdom
| | - Paul D Cotter
- APC Microbiome Ireland, University College Cork, Cork, Ireland.,Food Bioscience Department, Teagasc Food Research Centre, Fermoy, Ireland
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Anticandidal agent for multiple targets: the next paradigm in the discovery of proficient therapeutics/overcoming drug resistance. Future Med Chem 2019; 11:2955-2974. [DOI: 10.4155/fmc-2018-0479] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Candida albicans is a prominent human fungal pathogen. Current treatments are suffering a massive gap due to emerging resistance against available antifungals. Therefore, there is an ardent need for novel antifungal candidates that essentially have more than one target, as most antifungal repertoires are single-target drugs. Exploration of multiple-drug targeting in antifungal therapeutics is still pending. An extensive literature survey was performed to categorize and comprehend relevant studies and the current therapeutic scenario that led researchers to preferentially consider multitarget drug-based Candida infection therapy. With this article, we identified and compiled a few potent antifungal compounds that are directed toward multiple virulent targets in C. albicans. Such compound(s) provide an optimistic platform of multiple targeting and could leave a substantial impact on the development of effective antifungals.
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10
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Zhai P, Song J, Gao L, Lu L. A sphingolipid synthesis-related protein OrmA in Aspergillus fumigatus is responsible for azole susceptibility and virulence. Cell Microbiol 2019; 21:e13092. [PMID: 31376233 DOI: 10.1111/cmi.13092] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 06/17/2019] [Accepted: 07/29/2019] [Indexed: 01/24/2023]
Abstract
Previous studies identified that the budding yeast Saccharomyces cerevisiae have two sphingolipid synthesis-related proteins, Orm1p and Orm2p, that negatively regulate the activities of SPT, which is a key rate-limiting enzyme in sphingolipid synthesis. However, little is known about whether sphingolipids in the cell membrane, which are closely related to ergosterols, could affect the efficacy of azole drugs, which target to the ergosterol biosynthesis. In this study, through genome-wide homologue search analysis, we found that the Aspergillus fumigatus genome only contains one Orm homologue, referred to as OrmA for which the protein expression could be induced by azole antifungals in a dose-dependent manner. Deletion of ormA caused hypersensitivity to azoles, and adding the sphingolipid synthesis inhibitor myriocin rescued the azole susceptibility induced by lack of ormA. In contrast, overexpression of OrmA resulted in azole resistance, indicating that OrmA is a positive azole-response regulator. Further mechanism analysis verified that OrmA is related to drug susceptibility by affecting endoplasmic reticulum stress responses in an unfolded protein response pathway-HacA-dependent manner. Lack of ormA led to an abnormal profile of sphingolipid ceramide components accompanied by hypersensitivity to low temperatures. Furthermore, deletion of OrmA significantly reduced virulence in an immunosuppressed mouse model. The findings in this study collectively suggest that the sphingolipid metabolism pathway in A. fumigatus plays a critical role in azole susceptibility and fungal virulence.
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Affiliation(s)
- Pengfei Zhai
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, Nanjing, PR China
| | - Jinxing Song
- The Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province and School of Life Science, Jiangsu Normal University, Xuzhou, PR China
| | - Lu Gao
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, Nanjing, PR China
| | - Ling Lu
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, Nanjing, PR China
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11
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Kundu D, Hameed S, Fatima Z, Pasrija R. Phospholipid biosynthesis disruption renders the yeast cells sensitive to antifungals. Folia Microbiol (Praha) 2019; 65:121-131. [DOI: 10.1007/s12223-019-00713-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 04/25/2019] [Indexed: 10/26/2022]
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12
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The influence of N and S poles of static magnetic field (SMF) on Candida albicans hyphal formation and antifungal activity of amphotericin B. Folia Microbiol (Praha) 2019; 64:727-734. [PMID: 30788802 PMCID: PMC6861703 DOI: 10.1007/s12223-019-00686-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 01/23/2019] [Indexed: 12/27/2022]
Abstract
Due to the increasing number of Candida albicans’ infections and the resistance of this pathogenic fungus to drugs, new therapeutic strategies are sought. One of such strategies may be the use of static magnetic field (SMF). C. albicans cultures were subjected to static magnetic field of the induction 0.5 T in the presence of fluconazole and amphotericin B. We identified a reduction of C. albicans hyphal length. Also, a statistically significant additional effect on the viability of C. albicans was revealed when SMF was combined with the antimycotic drug amphotericin B. The synergistic effect of this antimycotic and SMF may be due to the fact that amphotericin B binds to ergosterol in plasma membrane and SMF similarly to MF could influence domain orientation in plasma membrane (PM).
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13
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Polke M, Leonhardt I, Kurzai O, Jacobsen ID. Farnesol signalling in Candida albicans – more than just communication. Crit Rev Microbiol 2017; 44:230-243. [DOI: 10.1080/1040841x.2017.1337711] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Melanie Polke
- Research Group Microbial Immunology, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute (HKI), Jena, Germany
| | - Ines Leonhardt
- Septomics Research Center, Friedrich Schiller University and Leibniz Institute for Natural Product Research and Infection Biology – Hans Knoell Institute (HKI), Jena, Germany
- Center for Sepsis Control and Care (CSCC), University Hospital, Jena, Germany
| | - Oliver Kurzai
- Septomics Research Center, Friedrich Schiller University and Leibniz Institute for Natural Product Research and Infection Biology – Hans Knoell Institute (HKI), Jena, Germany
- Center for Sepsis Control and Care (CSCC), University Hospital, Jena, Germany
- Friedrich Schiller University, Jena, Germany
| | - Ilse D. Jacobsen
- Research Group Microbial Immunology, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute (HKI), Jena, Germany
- Center for Sepsis Control and Care (CSCC), University Hospital, Jena, Germany
- Friedrich Schiller University, Jena, Germany
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14
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Konecna A, Toth Hervay N, Valachovic M, Gbelska Y. ERG6 gene deletion modifies Kluyveromyces lactis susceptibility to various growth inhibitors. Yeast 2016; 33:621-632. [PMID: 27668979 DOI: 10.1002/yea.3212] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 09/13/2016] [Accepted: 09/21/2016] [Indexed: 11/09/2022] Open
Abstract
The ERG6 gene encodes an S-adenosylmethionine dependent sterol C-24 methyltransferase in the ergosterol biosynthetic pathway. In this work we report the results of functional analysis of the Kluyveromyces lactis ERG6 gene. We cloned the KlERG6 gene, which was able to complement the erg6Δ mutation in both K. lactis and Saccharomyces cerevisiae. The lack of ergosterol in the Klerg6 deletion mutant was accompanied by increased expression of genes encoding the last steps of the ergosterol biosynthesis pathway as well as the KlPDR5 gene encoding an ABC transporter. The Klerg6Δ mutation resulted in reduced cell susceptibility to amphotericin B, nystatin and pimaricin and increased susceptibility to azole antifungals, fluphenazine, terbinafine, brefeldin A and caffeine. The susceptibility phenotype was suppressed by the KlPDR16 gene encoding one of the phosphatidylinositol transfer proteins belonging to the Sec14 family. Decreased activity of KlPdr5p in Klerg6Δ mutant (measured as the ability to efflux rhodamine 6G) together with increased amount of KlPDR5 mRNA suggest that the zymosterol which accumulates in the Klerg6Δ mutant may not fully compensate for ergosterol in the membrane targeting of efflux pumps. These results point to the fact that defects in sterol transmethylation appear to cause a multitude of physiological effects in K. lactis cells. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Alexandra Konecna
- Comenius University in Bratislava, Faculty of Natural Sciences, Department of Microbiology and Virology, Bratislava, Slovak Republic
| | - Nora Toth Hervay
- Comenius University in Bratislava, Faculty of Natural Sciences, Department of Microbiology and Virology, Bratislava, Slovak Republic
| | - Martin Valachovic
- Slovak Academy of Sciences, Institute of Animal Biochemistry and Genetics, Ivanka pri Dunaji, Slovak Republic
| | - Yvetta Gbelska
- Comenius University in Bratislava, Faculty of Natural Sciences, Department of Microbiology and Virology, Bratislava, Slovak Republic
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15
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Rautenbach M, Troskie AM, Vosloo JA, Dathe ME. Antifungal membranolytic activity of the tyrocidines against filamentous plant fungi. Biochimie 2016; 130:122-131. [DOI: 10.1016/j.biochi.2016.06.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2016] [Accepted: 06/15/2016] [Indexed: 12/11/2022]
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16
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Toth Hervay N, Konecna A, Balazfyova Z, Svrbicka A, Gbelska Y. Insight into the Kluyveromyces lactis Pdr1p regulon. Can J Microbiol 2016; 62:918-931. [PMID: 27556366 DOI: 10.1139/cjm-2016-0220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The overexpression of efflux pumps is an important mechanism leading to the development of multidrug resistance phenomenon. The transcription factor KlPdr1p, belonging to the Zn2Cys6 family, is a central regulator of efflux pump expression in Kluyveromyces lactis. To better understand how KlPDR1-mediated drug resistance is achieved in K. lactis, we used DNA microarrays to identify genes whose expression was affected by deletion or overexpression of the KlPDR1 gene. Eighty-nine targets of the KlPDR1 were identified. From those the transcription of 16 genes was induced in the transformant overexpressing KlPDR1* and simultaneously repressed in the Klpdr1Δ deletion mutant. Almost all of these genes contain putative binding motifs for the AP-1-like transcription factors in their promoters. Furthermore, we studied the possible interplay between KlPdr1p and KlYap1p transcription factors. Our results show that KlYap1p does not significantly contribute to the regulation of KlPDR1 gene expression in the presence of azoles. However, KlPDR1 expression markedly increased in the presence of hydrogen peroxide and hinged upon the presence of KlYap1p. Our results show that although both KlPdr1p and KlYap1p transcription factors are involved in the control of K. lactis multidrug resistance, further studies will be needed to determine their interplay.
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Affiliation(s)
- Nora Toth Hervay
- Comenius University in Bratislava, Faculty of Natural Sciences, Department of Microbiology and Virology, Ilkovicova 6, Mlynska dolina, 842 15 Bratislava, Slovak Republic.,Comenius University in Bratislava, Faculty of Natural Sciences, Department of Microbiology and Virology, Ilkovicova 6, Mlynska dolina, 842 15 Bratislava, Slovak Republic
| | - Alexandra Konecna
- Comenius University in Bratislava, Faculty of Natural Sciences, Department of Microbiology and Virology, Ilkovicova 6, Mlynska dolina, 842 15 Bratislava, Slovak Republic.,Comenius University in Bratislava, Faculty of Natural Sciences, Department of Microbiology and Virology, Ilkovicova 6, Mlynska dolina, 842 15 Bratislava, Slovak Republic
| | - Zuzana Balazfyova
- Comenius University in Bratislava, Faculty of Natural Sciences, Department of Microbiology and Virology, Ilkovicova 6, Mlynska dolina, 842 15 Bratislava, Slovak Republic.,Comenius University in Bratislava, Faculty of Natural Sciences, Department of Microbiology and Virology, Ilkovicova 6, Mlynska dolina, 842 15 Bratislava, Slovak Republic
| | - Alexandra Svrbicka
- Comenius University in Bratislava, Faculty of Natural Sciences, Department of Microbiology and Virology, Ilkovicova 6, Mlynska dolina, 842 15 Bratislava, Slovak Republic.,Comenius University in Bratislava, Faculty of Natural Sciences, Department of Microbiology and Virology, Ilkovicova 6, Mlynska dolina, 842 15 Bratislava, Slovak Republic
| | - Yvetta Gbelska
- Comenius University in Bratislava, Faculty of Natural Sciences, Department of Microbiology and Virology, Ilkovicova 6, Mlynska dolina, 842 15 Bratislava, Slovak Republic.,Comenius University in Bratislava, Faculty of Natural Sciences, Department of Microbiology and Virology, Ilkovicova 6, Mlynska dolina, 842 15 Bratislava, Slovak Republic
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17
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Rautenbach M, Troskie AM, Vosloo JA. Antifungal peptides: To be or not to be membrane active. Biochimie 2016; 130:132-145. [PMID: 27234616 DOI: 10.1016/j.biochi.2016.05.013] [Citation(s) in RCA: 123] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 05/20/2016] [Indexed: 02/06/2023]
Abstract
Most antifungal peptides (AFPs), if not all, have membrane activity, while some also have alternative targets. Fungal membranes share many characteristics with mammalian membranes with only a few differences, such as differences in sphingolipids, phosphatidylinositol (PI) content and the main sterol is ergosterol. Fungal membranes are also more negative and a better target for cationic AFPs. Targeting just the fungal membrane lipids such as phosphatidylinositol and/or ergosterol by AFPs often translates into mammalian cell toxicity. Conversely, a specific AFP target in the fungal pathogen, such as glucosylceramide, mannosyldiinositol phosphorylceramide or a fungal protein target translates into high pathogen selectivity. However, a lower target concentration, absence or change in the specific fungal target can naturally lead to resistance, although such resistance in turn could result in reduced pathogen virulence. The question is then to be or not to be membrane active - what is the best choice for a successful AFP? In this review we deliberate on this question by focusing on the recent advances in our knowledge on how natural AFPs target fungi.
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Affiliation(s)
- Marina Rautenbach
- BIOPEP Peptide Group, Department of Biochemistry, University of Stellenbosch, South Africa.
| | - Anscha M Troskie
- BIOPEP Peptide Group, Department of Biochemistry, University of Stellenbosch, South Africa
| | - J Arnold Vosloo
- BIOPEP Peptide Group, Department of Biochemistry, University of Stellenbosch, South Africa
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18
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Singh A, Yadav V, Prasad R. Comparative lipidomics in clinical isolates of Candida albicans reveal crosstalk between mitochondria, cell wall integrity and azole resistance. PLoS One 2012; 7:e39812. [PMID: 22761908 PMCID: PMC3384591 DOI: 10.1371/journal.pone.0039812] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Accepted: 05/26/2012] [Indexed: 11/19/2022] Open
Abstract
Prolonged usage of antifungal azoles which target enzymes involved in lipid biosynthesis invariably leads to the development of multi-drug resistance (MDR) in Candida albicans. We had earlier shown that membrane lipids and their fluidity are closely linked to the MDR phenomenon. In one of our recent studies involving comparative lipidomics between azole susceptible (AS) and azole resistant (AR) matched pair clinical isolates of C. albicans, we could not see consistent differences in the lipid profiles of AS and AR strains because they came from different patients and so in this study, we have used genetically related variant recovered from the same patient collected over a period of 2-years. During this time, the levels of fluconazole (FLC) resistance of the strain increased by over 200-fold. By comparing the lipid profiles of select isolates, we were able to observe gradual and statistically significant changes in several lipid classes, particularly in plasma membrane microdomain specific lipids such as mannosylinositolphosphorylceramides and ergosterol, and in a mitochondrial specific phosphoglyceride, phosphatidyl glycerol. Superimposed with these quantitative and qualitative changes in the lipid profiles, were simultaneous changes at the molecular lipid species levels which again coincided with the development of resistance to FLC. Reverse transcriptase-PCR of the key genes of the lipid metabolism validated lipidomic picture. Taken together, this study illustrates how the gradual corrective changes in Candida lipidome correspond to the development of FLC tolerance. Our study also shows a first instance of the mitochondrial membrane dysfunction and defective cell wall (CW) in clinical AR isolates of C. albicans, and provides evidence of a cross-talk between mitochondrial lipid homeostasis, CW integrity and azole tolerance.
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Affiliation(s)
- Ashutosh Singh
- Membrane Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Vipin Yadav
- Membrane Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Rajendra Prasad
- Membrane Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
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19
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Wang L, Jia Y, Tang RJ, Xu Z, Cao YB, Jia XM, Jiang YY. Proteomic analysis of Rta2p-dependent raft-association of detergent-resistant membranes in Candida albicans. PLoS One 2012; 7:e37768. [PMID: 22662216 PMCID: PMC3360622 DOI: 10.1371/journal.pone.0037768] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Accepted: 04/24/2012] [Indexed: 11/19/2022] Open
Abstract
In Candida albicans, lipid rafts (also called detergent-resistant membranes, DRMs) are involved in many cellular processes and contain many important proteins. In our previous study, we demonstrated that Rta2p was required for calcineurin-mediated azole resistance and sphingoid long-chain base release in C. albicans. Here, we found that Rta2p was co-localized with raft-constituted ergosterol on the plasma membrane of C. albicans. Furthermore, this membrane expression pattern was totally disturbed by inhibitors of either ergosterol or sphingolipid synthesis. Biochemical fractionation of DRMs together with immunoblot uncovered that Rta2p, along with well-known DRM-associated proteins (Pma1p and Gas1p homologue), was associated with DRMs and their associations were blocked by inhibitors of either ergosterol or sphingolipid synthesis. Finally, we used the proteomic analysis together with immunoblot and identified that Rta2p was required for the association of 10 proteins with DRMs. These 5 proteins (Pma1p, Gas1p homologue, Erg11p, Pmt2p and Ali1p) have been reported to be DRM-associated and also that Erg11p is a well-known target of azoles in C. albicans. In conclusion, our results showed that Rta2p was predominantly localized in lipid rafts and was required for the association of certain membrane proteins with lipid rafts in C. albicans.
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Affiliation(s)
- Lin Wang
- School of Pharmacy, Second Military Medical University, Shanghai, China
- Department of Immunology, Tongji University School of Medicine, Shanghai, China
| | - Yu Jia
- School of Pharmacy, Second Military Medical University, Shanghai, China
| | - Ren-Jie Tang
- School of Pharmacy, Second Military Medical University, Shanghai, China
| | - Zheng Xu
- School of Pharmacy, Second Military Medical University, Shanghai, China
| | - Yong-Bing Cao
- School of Pharmacy, Second Military Medical University, Shanghai, China
| | - Xin-Ming Jia
- Department of Immunology, Tongji University School of Medicine, Shanghai, China
- * E-mail: (X-MJ); (Y-YJ)
| | - Yuan-Ying Jiang
- School of Pharmacy, Second Military Medical University, Shanghai, China
- * E-mail: (X-MJ); (Y-YJ)
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20
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Singh A, Prasad R. Comparative lipidomics of azole sensitive and resistant clinical isolates of Candida albicans reveals unexpected diversity in molecular lipid imprints. PLoS One 2011; 6:e19266. [PMID: 21559392 PMCID: PMC3084813 DOI: 10.1371/journal.pone.0019266] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Accepted: 03/24/2011] [Indexed: 12/27/2022] Open
Abstract
Although transcriptome and proteome approaches have been applied to determine the regulatory circuitry behind multidrug resistance (MDR) in Candida, its lipidome remains poorly characterized. Lipids do acclimatize to the development of MDR in Candida, but exactly how the acclimatization is achieved is poorly understood. In the present study, we have used a high-throughput mass spectrometry-based shotgun approach and analyzed the lipidome of genetically matched clinical azole-sensitive (AS) and -resistant (AR) isolates of C. albicans. By comparing the lipid profiling of matched isolates, we have identified major classes of lipids and determined more than 200 individual molecular lipid species among these major classes. The lipidome analysis has been statistically validated by principal component analysis. Although each AR isolate was similar with regard to displaying a high MIC to drugs, they had a distinct lipid imprint. There were some significant commonalities in the lipid profiles of these pairs, including molecular lipid species ranging from monounsaturated to polyunsaturated fatty acid-containing phosphoglycerides. Consistent fluctuation in phosphatidyl serine, mannosylinositolphosphorylceramides, and sterol esters levels indicated their compensatory role in maintaining lipid homeostasis among most AR isolates. Notably, overexpression of either CaCdr1p or CaMdr1p efflux pump proteins led to a different lipidomic response among AR isolates. This study clearly establishes the versatility of lipid metabolism in handling azole stress among various matched AR isolates. This comprehensive lipidomic approach will serve as a resource for assessing strategies aimed at disrupting the functions of Candida lipids, particularly the functional interactions between lipids and MDR determinants.
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Affiliation(s)
- Ashutosh Singh
- Membrane Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Rajendra Prasad
- Membrane Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
- * E-mail:
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21
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Iwaki T, Iefuji H, Hiraga Y, Hosomi A, Morita T, Giga-Hama Y, Takegawa K. Multiple functions of ergosterol in the fission yeast Schizosaccharomyces pombe. MICROBIOLOGY-SGM 2008; 154:830-841. [PMID: 18310029 DOI: 10.1099/mic.0.2007/011155-0] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Sterols are a major class of membrane lipids in eukaryotes. In Schizosaccharomyces pombe, sterol 24-C-methyltransferase (Erg6p), C-8 sterol isomerase (Erg2p), C-5 sterol desaturase (Erg31p, Erg32p), C-22 sterol desaturase (Erg5p) and C-24 (28) sterol reductase (Sts1p/Erg4p) have been predicted, but not yet determined, to catalyse a sequence of reactions from zymosterol to ergosterol. Disruption mutants of these genes were unable to synthesize ergosterol, and most were tolerant to the polyene drugs amphotericin B and nystatin. Disruption of erg31(+) or erg32(+) did not cause ergosterol deficiency or tolerance to polyene drugs, indicating that the two C-5 sterol desaturases have overlapping functions. GFP-tagged DRM (detergent-resistant membrane)-associated protein Pma1p localized to the plasma membrane in ergDelta mutants. DRM fractionation revealed that the association between Pma1-GFP and DRM was weakened in erg6Delta but not in other erg mutants. Several GFP-tagged plasma membrane proteins were tested, and an amino acid permease homologue, SPBC359.03c, was found to mislocalize to intracellular punctate structures in the ergDelta mutants. These results indicate that these proteins are responsible for ergosterol biosynthesis in fission yeast, similar to the situation in Saccharomyces cerevisiae. Furthermore, in fission yeast, ergosterol is important for plasma membrane structure and function and for localization of plasma membrane proteins.
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Affiliation(s)
- Tomoko Iwaki
- Research Center, Asahi Glass Co. Ltd, Yokohama, Kanagawa 221-8755, Japan.,Department of Life Sciences, Faculty of Agriculture, Kagawa University, Miki-cho, Kagawa 761-0795, Japan
| | - Haruyuki Iefuji
- National Research Institute of Brewing, 3-7-1 Kagamiyama, Higashi Hiroshima, Hiroshima 739-0046, Japan
| | - Yoshikazu Hiraga
- Department of Chemistry, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi Hiroshima, Hiroshima 739-8526, Japan
| | - Akira Hosomi
- Department of Life Sciences, Faculty of Agriculture, Kagawa University, Miki-cho, Kagawa 761-0795, Japan
| | - Tomotake Morita
- Research Center, Asahi Glass Co. Ltd, Yokohama, Kanagawa 221-8755, Japan.,Department of Life Sciences, Faculty of Agriculture, Kagawa University, Miki-cho, Kagawa 761-0795, Japan
| | - Yuko Giga-Hama
- Research Center, Asahi Glass Co. Ltd, Yokohama, Kanagawa 221-8755, Japan
| | - Kaoru Takegawa
- Department of Life Sciences, Faculty of Agriculture, Kagawa University, Miki-cho, Kagawa 761-0795, Japan
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22
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Responses of pathogenic and nonpathogenic yeast species to steroids reveal the functioning and evolution of multidrug resistance transcriptional networks. EUKARYOTIC CELL 2007; 7:68-77. [PMID: 17993571 DOI: 10.1128/ec.00256-07] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Steroids are known to induce pleiotropic drug resistance states in hemiascomycetes, with tremendous potential consequences for human fungal infections. Our analysis of gene expression in Saccharomyces cerevisiae and Candida albicans cells subjected to three different concentrations of progesterone revealed that their pleiotropic drug resistance (PDR) networks were strikingly sensitive to steroids. In S. cerevisiae, 20 of the Pdr1p/Pdr3p target genes, including PDR3 itself, were rapidly induced by progesterone, which mimics the effects of PDR1 gain-of-function alleles. This unique property allowed us to decipher the respective roles of Pdr1p and Pdr3p in PDR induction and to define functional modules among their target genes. Although the expression profiles of the major PDR transporters encoding genes ScPDR5 and CaCDR1 were similar, the S. cerevisiae global PDR response to progesterone was only partly conserved in C. albicans. In particular, the role of Tac1p, the main C. albicans PDR regulator, in the progesterone response was apparently restricted to five genes. These results suggest that the C. albicans and S. cerevisiae PDR networks, although sharing a conserved core regarding the regulation of membrane properties, have different structures and properties. Additionally, our data indicate that other as yet undiscovered regulators may second Tac1p in the C. albicans drug response.
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23
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Bandyopadhyay A, Blakeslee JJ, Lee OR, Mravec J, Sauer M, Titapiwatanakun B, Makam SN, Bouchard R, Geisler M, Martinoia E, Friml J, Peer WA, Murphy AS. Interactions of PIN and PGP auxin transport mechanisms. Biochem Soc Trans 2007; 35:137-41. [PMID: 17233620 DOI: 10.1042/bst0350137] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Polarized transport of the plant hormone auxin influences multiple growth processes in plants and is regulated by plasma-membrane-localized efflux and uptake carriers. The PGP (P-glycoprotein) ABC transporters (ATP-binding-cassette transporters), PIN (pin-formed) subfamily of major facilitator proteins and members of AUX/LAX families have been shown to independently transport auxin both in planta and in heterologous systems. However, PIN- and PGP-mediated transport in heterologous systems exhibits decreased substrate specificity and inhibitor-sensitivity compared with what is seen in plants and plant cells. To determine whether PIN–PGP interactions enhance transport specificity, we analysed interactions of the representative auxin-transporting PGPs with PIN1 and AUX1 in planta and in heterologous systems. Here, we provide evidence that PINs and PGPs interact and function both independently and co-ordinately to control polar auxin transport and impart transport specificity and directionality. These interactions take place in protein complexes stabilized by PGPs in detergent-resistant microdomains.
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Affiliation(s)
- A Bandyopadhyay
- Department of Horticulture, Purdue University, West Lafayette, IN 47907-2010, USA
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24
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Mulhern SM, Logue ME, Butler G. Candida albicans transcription factor Ace2 regulates metabolism and is required for filamentation in hypoxic conditions. EUKARYOTIC CELL 2006; 5:2001-13. [PMID: 16998073 PMCID: PMC1694816 DOI: 10.1128/ec.00155-06] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2006] [Accepted: 09/13/2006] [Indexed: 11/20/2022]
Abstract
Ace2 transcription factor family genes are found in many fungal genomes and are required for regulation of expression of genes involved in cell separation. We used transcriptional profiling to identify the targets of Ace2 in Candida albicans, and we show that these include several cell wall components, such as glucanases and glycosylphosphatidylinositol-anchored proteins. Expression is downregulated in ace2 deletion mutants in both yeast and hyphal cells. In addition, deleting ace2 results in dramatic changes in expression of metabolic pathways. Expression of glycolytic enzymes is reduced, while expression of respiratory genes (including those involved in the tricarboxylic acid cycle, oxidative phosphorylation, and ATP synthesis) is increased. Similar changes occur in both yeast and hyphal cells. In contrast, genes required for acetyl-coenzyme A and lipid metabolism are upregulated in an ace2 deletion mutant grown predominantly as yeast cells but are downregulated in hyphae. These results suggest that in wild-type strains, Ace2 acts to increase glycolysis and reduce respiration. This is supported by the observation that deleting ace2 results in increased resistance to antimycin A, a drug that inhibits respiration. We also show that Ace2 is required for filamentation in response to low oxygen concentrations (hypoxia). We suggest that filamentation is induced in wild-type cells by reducing respiration (using low oxygen or respiratory drugs) and that mutants with increased respiratory activity fail to undergo filamentation under these conditions.
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Affiliation(s)
- Siobhan M Mulhern
- UCD School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
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25
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Ruckenstuhl C, Lang S, Poschenel A, Eidenberger A, Baral PK, Kohút P, Hapala I, Gruber K, Turnowsky F. Characterization of squalene epoxidase of Saccharomyces cerevisiae by applying terbinafine-sensitive variants. Antimicrob Agents Chemother 2006; 51:275-84. [PMID: 17043127 PMCID: PMC1797698 DOI: 10.1128/aac.00988-06] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Squalene epoxidase (SE) is the target of terbinafine, which specifically inhibits the fungal enzyme in a noncompetitive manner. On the basis of functional homologies to p-hydroxybenzoate hydroxylase (PHBH) from Pseudomonas fluorescens, the Erg1 protein contains two flavin adenine dinucleotide (FAD) domains and one nucleotide binding (NB) site. By in vitro mutagenesis of the ERG1 gene, which codes for the Saccharomyces cerevisiae SE, we isolated erg1 alleles that conferred increased terbinafine sensitivity or that showed a lethal phenotype when they were expressed in erg1-knockout strain KLN1. All but one of the amino acid substitutions affected conserved FAD/nucleotide binding sites. The G(25)S, D(335)X (W, F, P), and G(210)A substitutions in the FADI, FADII, and NB sites, respectively, rendered the SE variants nonfunctional. The G(30)S and L(37)P variants exhibited decreased enzymatic activity, accompanied by a sevenfold increase in erg1 mRNA levels and an altered sterol composition, and rendered KLN1 more sensitive not only to allylamines (10 to 25 times) but also to other ergosterol biosynthesis inhibitors. The R(269)G variant exhibited moderately reduced SE activity and a 5- to 10-fold increase in allylamine sensitivity but no cross-sensitivity to the other ergosterol biosynthesis inhibitors. To further elucidate the roles of specific amino acids in SE function and inhibitor interaction, a homology model of Erg1p was built on the basis of the crystal structure of PHBH. All experimental data obtained with the sensitive Erg1 variants support this model. In addition, the amino acids responsible for terbinafine resistance, although they are distributed along the sequence of Erg1p, cluster on the surface of the Erg1p model, giving rise to a putative binding site for allylamines.
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Affiliation(s)
- Christoph Ruckenstuhl
- Institute of Molecular Biosciences, Karl-Franzens-Universität Graz, Universitätsplatz 2, A-8010 Graz, Austria
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26
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Current awareness on yeast. Yeast 2006. [DOI: 10.1002/yea.1315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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