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Park HG, Kim V, Kim H, Lee R, Cho MA, Park SW, Chun YJ, Kim D. CYP52A23 from Candida albicans and its Substrate Preference for Fatty Acid Hydroxylation. Arch Biochem Biophys 2019; 671:27-34. [PMID: 31181182 DOI: 10.1016/j.abb.2019.06.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 06/05/2019] [Accepted: 06/06/2019] [Indexed: 01/07/2023]
Abstract
The pathogenic fungus Candida albicans contains genes encoding five fatty acid hydroxylases belonging to the CYP52 family in its genome. Our previous study reported that CYP52A21 demonstrated typical omega-hydroxylation of lauric acid (Kim D, Cryle MJ, De Voss JJ, Ortiz de Montellano PR (2007) Arch Biochem Biophys 464, 213-220). Functional characterization of CYP52 fatty acid hydroxylases was studied, and their selectivity for hydroxylation was analyzed. Genes for four other CYP52 members (CYP52A22, CYP52A23, CYP52A24, and CYP52C3) from C. albicans were cloned, and their recombinant enzymes were expressed in Escherichia coli. CO-binding spectral analyses showed that the functional P450 holoenzyme was obtained only in CYP52A23, while no holoenzyme peak was observed in the other three CYP52 enzymes. Spectral change of the type II binding was observed in purified CYP52A23 when titrated with fatty acids but none was observed with alkanes. The gas chromatography-mass spectrometry (GC-MS) analysis revealed that CYP52A23 predominantly exhibited omega-hydroxylation activity during the oxidation reaction of fatty acids. Interestingly, it was found that CYP52A23 preferred longer-chain fatty acids (stearic acid and arachidic acid) for its catalytic activities while CYP52A21 preferred mid-chain fatty acids (lauric acid and mystic acid). To analyze the selectivity of fatty acids, hybrid mutagenesis of genes encoding CYP52A21 and CYP52A23 by overlap extension polymerase chain reaction was conducted. Two hybrid mutants containing the N-terminal fragments of CYP52A21 and C-terminal fragments of CYP52A23 displayed higher catalytic activity in palmitic acid and arachidic acid. These results suggested that the C-terminal part of CYP52A23 may be responsible for its preference to longer-chain fatty acids.
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Affiliation(s)
- Hyoung-Goo Park
- Department of Biological Sciences, Konkuk University, Seoul, 05029, South Korea
| | - Vitchan Kim
- Department of Biological Sciences, Konkuk University, Seoul, 05029, South Korea
| | - Harim Kim
- Department of Biological Sciences, Konkuk University, Seoul, 05029, South Korea
| | - Rowoon Lee
- Department of Biological Sciences, Konkuk University, Seoul, 05029, South Korea
| | - Myung-A Cho
- Department of Biological Sciences, Konkuk University, Seoul, 05029, South Korea
| | - Sung-Woo Park
- Division of Respiratory and Allergy, Department of Internal Medicine, Soonchunhyang University Bucheon Hospital, Bucheon, 14584, South Korea
| | - Young-Jin Chun
- College of Pharmacy, Chung-Ang University, Seoul, 06974, South Korea
| | - Donghak Kim
- Department of Biological Sciences, Konkuk University, Seoul, 05029, South Korea.
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Honorato Siqueira T, Martínez L. Molecular simulations of fluconazole-mediated inhibition of sterol biosynthesis. J Biomol Struct Dyn 2019; 38:1659-1669. [DOI: 10.1080/07391102.2019.1614998] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Tayane Honorato Siqueira
- Institute of Chemistry and Center for Computing in Engineering & Sciences, University of Campinas, Campinas, Brazil
| | - Leandro Martínez
- Institute of Chemistry and Center for Computing in Engineering & Sciences, University of Campinas, Campinas, Brazil
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Benedetti VP, Savi DC, Aluizio R, Adamoski D, Kava V, Galli-Terasawa LV, Glienke C. ERG11 gene polymorphisms and susceptibility to fluconazole in Candida isolates from diabetic and kidney transplant patients. Rev Soc Bras Med Trop 2019; 52:e20180473. [PMID: 30843968 DOI: 10.1590/0037-8682-0473-2018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 01/25/2019] [Indexed: 11/22/2022] Open
Abstract
INTRODUCTION Candidiasis is the most frequent opportunistic mycosis in humans and can cause mortality, particularly in immunodeficient patients. One major concern is the increasing number of infections caused by drug-resistant Candidas trains, as these cannot be efficiently treated with standard therapeutics. The most common mechanism of fluconazole resistance in Candida is mutation of ERG11, a gene involved in the biosynthesis of ergosterol, a compound essential for cell integrity and membrane function. METHODS Based on this knowledge, we investigated polymorphisms in the ERG11 gene of 3 Candida species isolated from immunocompromised and immunocompetent patients. In addition, we correlated the genetic data with the fluconazole susceptibility profile of the Candida isolates. RESULTS A total of 80 Candida albicans, 8 Candida tropicalis and 6 Candida glabrata isolates were obtained from the saliva of diabetic, kidney transplant and immunocompetent patients. Isolates were considered susceptible to fluconazole if the minimum inhibitory concentration was lower than 8 μg/mL. The amino acid mutations F105L, D116E, K119N, S137L, and K128T were observed in C. albicans isolates, and T224C and G263A were found in C. tropicalis isolates. CONCLUSIONS Despite the high number of polymorphisms observed, the mutations occurred in regions that are not predicted to interfere with ergosterol synthesis, and therefore are not related to fluconazole resistance.
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Affiliation(s)
- Volmir Pitt Benedetti
- Departamento de Microbiologia da Universidade Paranaense, Francisco Beltrão, PR, Brasil.,Departamento de Patologia Básica, Universidade Federal do Paraná, Curitiba, PR, Brasil
| | | | - Rodrigo Aluizio
- Departamento de Genética, Universidade Federal do Paraná, Curitiba, PR, Brasil
| | - Douglas Adamoski
- Departamento de Genética, Universidade Federal do Paraná, Curitiba, PR, Brasil
| | - Vanessa Kava
- Departamento de Genética, Universidade Federal do Paraná, Curitiba, PR, Brasil
| | | | - Chirlei Glienke
- Departamento de Patologia Básica, Universidade Federal do Paraná, Curitiba, PR, Brasil.,Departamento de Genética, Universidade Federal do Paraná, Curitiba, PR, Brasil
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Özdemir A, Sever B, Altıntop MD. New Benzodioxole-based Pyrazoline Derivatives: Synthesis and Anticandidal, In silico ADME, Molecular Docking Studies. LETT DRUG DES DISCOV 2018. [DOI: 10.2174/1570180815666180326152726] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Background:
Azoles are commonly used in the treatment and prevention of fungal
infections. They suppress fungal growth by acting on the heme group of lanosterol 14α-demethylase
enzyme (CYP51), thus blocking the biosynthesis of ergosterol.
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Objectives: Due to the importance of pyrazolines in the field of antifungal drug design, we aimed to
design and synthesize new pyrazoline-based anticandidal agents.
Methods:
New pyrazoline derivatives were synthesized via the reaction of 1-(chloroacetyl)-3-(2-
thienyl)-5-(1,3-benzodioxol-5-yl)-2-pyrazoline with aryl thiols. These compounds were evaluated
for their in vitro antifungal effects on Candida species. Docking studies were performed to predict
the affinity of the most effective anticandidal agents to substrate binding site of CYP51. Furthermore,
MTT assay was performed to determine the cytotoxic effects of the compounds on NIH/3T3
mouse embryonic fibroblast cell line. A computational study for the prediction of ADME properties
of all compounds was also carried out.
Results:
Compounds 5, 8, 10 and 12 were found as the most potent anticandidal agents against
Candida albicans and Candida glabrata in this series with the same MIC values of ketoconazole
and they also exhibited low toxicity against NIH/3T3 cells. Docking results indicated that all these
compounds showed good binding affinity into the active site of CYP51. In particular, chloro
substituted compounds 8 and 12 bind to CYP51 through direct coordination with the heme group.
According to in silico studies, compound 8 only violated one parameter of Lipinski’s rule of five,
making it a potential orally bioavailable agent.
Conclusion:
Compound 8 was defined as a promising candidate for further in vitro and in vivo
studies.
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Affiliation(s)
- Ahmet Özdemir
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Anadolu University, 26470 Eskişehir, Turkey
| | - Belgin Sever
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Anadolu University, 26470 Eskişehir, Turkey
| | - Mehlika Dilek Altıntop
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Anadolu University, 26470 Eskişehir, Turkey
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Zhang Y, Liu B, Zhang Z, Wang L, Guo H, Li Z, He P, Liu Z, Fang J. Differential Expression of P450 Genes and nAChR Subunits Associated With Imidacloprid Resistance in Laodelphax striatellus (Hemiptera: Delphacidae). JOURNAL OF ECONOMIC ENTOMOLOGY 2018; 111:1382-1387. [PMID: 29617902 DOI: 10.1093/jee/toy051] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Indexed: 05/27/2023]
Abstract
Imidacloprid is a key insecticide used for controlling sucking insect pests, including the small brown planthopper (Laodelphax striatellus, Fallén) (Hemiptera: Delphacidae), an important agricultural pest of rice. A strain of L. striatellus (YN-ILR) developed 21-fold resistance when selected with imidacloprid on a susceptible YN strain. An in vitro study on piperonyl butoxide synergism indicated that enhanced detoxification mediated by cytochrome P450s contributed to imidacloprid resistance to some extent, and multiple P450 genes showed altered expression in the imidacloprid-resistant YN-ILR strain compared with the susceptible YN strain (CYP425B1-CYP6BD10 had 1.51- to 11.45-fold higher expression, CYP4CE2-CYP4DD1V2 had 0.12- to 0.57-fold lower expression). While there were no mutations in target nicotinic acetylcholine receptor (nAChR) genes, subunits of Lsα1, Lsβ1, and Lsβ3 in the YN-ILR strain showed 3.86-, 4.39-, and 2.59-fold higher expression and Lsa8 displayed 0.38-fold lower expression than the YN strain. Moreover, 21-fold moderate imidacloprid resistance in individuals of L. striatellus did not produce a fitness cost. The findings suggest that L. striatellus has the capacity to develop resistance to imidacloprid through P450 detoxification and potential target nAChR expression changes, and moderate imidacloprid resistance was not associated with a fitness cost.
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Affiliation(s)
- Yueliang Zhang
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Nanjing, China
| | - Baosheng Liu
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Nanjing, China
| | - Zhichun Zhang
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Nanjing, China
| | - Lihua Wang
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Nanjing, China
| | - Huifang Guo
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Nanjing, China
| | - Zhong Li
- Shanghai Key Laboratory of Chemical Biology, School of Pharmacy, East China University of Science and Technology, Shanghai, China
| | - Peng He
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang, China
| | - Zewen Liu
- Key Laboratory of Monitoring and Management of Plant Disease and Insects, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, China
| | - Jichao Fang
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Nanjing, China
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Kim V, Yeom S, Lee Y, Park HG, Cho MA, Kim H, Kim D. In vitro functional analysis of human cytochrome P450 2A13 genetic variants: P450 2A13*2, *3, *4, and *10. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2018; 81:493-501. [PMID: 29652224 DOI: 10.1080/15287394.2018.1460784] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Humans possess three cytochrome P450 enzymes in the 2A subfamily (2A6, 2A7, and 2A13). P450 2A13 is mainly expressed in the human trachea and lung, whereas P450 2A6 is found in human liver. The P450 2A13 enzyme may be considered as the primary enzyme responsible for metabolic activation of many tobacco-specific carcinogens. Genetic variations significantly influence the toxicological consequences attributed to tobacco smoking. The aim of this study was to examine the in vitro functional activities of five P450 2A13 genetic variations (R257C, 133_134insT, R101Q, I331T, and R257C/I331T) in P450 2A13*2, *3, *4, and *10 alleles. Mutant clones were constructed and their recombinant enzymes were expressed in Escherichia coli. P450 2A13 mutants containing R257C, 133_134insT, I331T, and R257C/I331T displayed P450 holoenzyme spectra. The R101Q mutant was not apparently expressed. P450 2A13 enzymes displayed the typical type I binding spectra to coumarin and the calculated binding affinities of R257C, R257C/I331T, and 133_134insT mutants were decreased approximately three- to sevenfold. In catalytic analyses of purified mutant enzymes for coumarin and nicotine, the R257C and I331T mutants exhibited lower kcat values with catalytic efficiencies reduced up to approximately 20%. The double mutation of R257C/I331T induced increased Km values and diminished kcat values that resulted in >50% decrease in catalytic efficiencies. For 133_134insT mutant, catalytic activities were not markedly saturated but the measured rates at the highest concentrations were significantly lower than those of the wild-type or other mutant enzymes. Functional analysis of these variations in P450 2A13 allelic variants may help to understand the consequences of P450 2A13 polymorphism in bioactivation of many tobacco-derived carcinogens.
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Affiliation(s)
- Vitchan Kim
- a Department of Biological Sciences , Konkuk University , Seoul , Korea
| | - Sora Yeom
- a Department of Biological Sciences , Konkuk University , Seoul , Korea
| | - Yejin Lee
- a Department of Biological Sciences , Konkuk University , Seoul , Korea
| | - Hyoung-Goo Park
- a Department of Biological Sciences , Konkuk University , Seoul , Korea
| | - Myung-A Cho
- a Department of Biological Sciences , Konkuk University , Seoul , Korea
| | - Harim Kim
- a Department of Biological Sciences , Konkuk University , Seoul , Korea
| | - Donghak Kim
- a Department of Biological Sciences , Konkuk University , Seoul , Korea
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Wu Y, Li C, Wang Z, Gao J, Tang Z, Chen H, Ying C. Clonal spread and azole-resistant mechanisms of non-susceptible Candida albicans isolates from vulvovaginal candidiasis patients in three Shanghai maternity hospitals. Med Mycol 2017; 56:687-694. [PMID: 29136186 DOI: 10.1093/mmy/myx099] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Affiliation(s)
- YongQin Wu
- Department of Clinical Laboratory, Obstetrics and Gynecology Hospital of Fudan University, No. 419 Fangxie Road, Shanghai, 200011, China
| | - Cui Li
- Department of Clinical Laboratory, Obstetrics and Gynecology Hospital of Fudan University, No. 419 Fangxie Road, Shanghai, 200011, China
| | - ZhiHeng Wang
- Department of Clinical Laboratory, Obstetrics and Gynecology Hospital of Fudan University, No. 419 Fangxie Road, Shanghai, 200011, China
| | - Jing Gao
- Department of Clinical Laboratory, Obstetrics and Gynecology Hospital of Fudan University, No. 419 Fangxie Road, Shanghai, 200011, China
| | - ZhenHua Tang
- Department of Clinical Laboratory, International Peace Maternity and Child Health Hospital, No. 910 Hengshan Road, Shanghai, 200030, China
| | - HuiFen Chen
- Department of Clinical Laboratory, Shanghai First Maternity and Infant Hospital, No. 536 Changle Road, Shanghai, 200040, China
| | - ChunMei Ying
- Department of Clinical Laboratory, Obstetrics and Gynecology Hospital of Fudan University, No. 419 Fangxie Road, Shanghai, 200011, China
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Ke X, Ding GJ, Ma BX, Liu ZQ, Zhang JF, Zheng YG. Characterization of a novel CYP51 from Rhodococcus triatomae and its NADH-ferredoxin reductase-coupled application in lanosterol 14α-demethylation. Process Biochem 2017. [DOI: 10.1016/j.procbio.2017.07.030] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Lim YR, Han S, Kim JH, Park HG, Lee GY, Le TK, Yun CH, Kim D. Characterization of a Biflaviolin Synthase CYP158A3 from Streptomyces avermitilis and Its Role in the Biosynthesis of Secondary Metabolites. Biomol Ther (Seoul) 2017; 25:171-176. [PMID: 27956713 PMCID: PMC5340542 DOI: 10.4062/biomolther.2016.182] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Revised: 09/22/2016] [Accepted: 09/22/2016] [Indexed: 11/16/2022] Open
Abstract
Streptomyces avermitilis produces clinically useful drugs such as avermectins and oligomycins. Its genome contains approximately 33 cytochrome P450 genes and they seem to play important roles in the biosynthesis of many secondary metabolites. The SAV_7130 gene from S. avermitilis encodes CYP158A3. The amino acid sequence of this enzyme has high similarity with that of CYP158A2, a biflaviolin synthase from S. coelicolor A3(2). Recombinant S. avermitilis CYP158A3 was heterologously expressed and purified. It exhibited the typical P450 Soret peak at 447 nm in the reduced CO-bound form. Type I binding spectral changes were observed when CYP158A3 was titrated with myristic acid; however, no oxidative product was formed. An analog of flaviolin, 2-hydroxynaphthoquinone (2-OH NQ) displayed similar type I binding upon titration with purified CYP158A3. It underwent an enzymatic reaction forming dimerized product. A homology model of CYP158A3 was superimposed with the structure of CYP158A2, and the majority of structural elements aligned. These results suggest that CYP158A3 might be an orthologue of biflaviolin synthase, catalyzing C-C coupling reactions during pigment biosynthesis in S. avermitilis.
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Affiliation(s)
- Young-Ran Lim
- Department of Biological Sciences, Konkuk University, Seoul 05025, Republic of Korea
| | - Songhee Han
- Department of Biological Sciences, Konkuk University, Seoul 05025, Republic of Korea
| | - Joo-Hwan Kim
- Department of Biological Sciences, Konkuk University, Seoul 05025, Republic of Korea
| | - Hyoung-Goo Park
- Department of Biological Sciences, Konkuk University, Seoul 05025, Republic of Korea
| | - Ga-Young Lee
- School of Biological Sciences and Technology, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Thien-Kim Le
- School of Biological Sciences and Technology, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Chul-Ho Yun
- School of Biological Sciences and Technology, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Donghak Kim
- Department of Biological Sciences, Konkuk University, Seoul 05025, Republic of Korea
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Teixeira M, Moreno L, Stielow B, Muszewska A, Hainaut M, Gonzaga L, Abouelleil A, Patané J, Priest M, Souza R, Young S, Ferreira K, Zeng Q, da Cunha M, Gladki A, Barker B, Vicente V, de Souza E, Almeida S, Henrissat B, Vasconcelos A, Deng S, Voglmayr H, Moussa T, Gorbushina A, Felipe M, Cuomo C, de Hoog GS. Exploring the genomic diversity of black yeasts and relatives ( Chaetothyriales, Ascomycota). Stud Mycol 2017; 86:1-28. [PMID: 28348446 PMCID: PMC5358931 DOI: 10.1016/j.simyco.2017.01.001] [Citation(s) in RCA: 115] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The order Chaetothyriales (Pezizomycotina, Ascomycetes) harbours obligatorily melanised fungi and includes numerous etiologic agents of chromoblastomycosis, phaeohyphomycosis and other diseases of vertebrate hosts. Diseases range from mild cutaneous to fatal cerebral or disseminated infections and affect humans and cold-blooded animals globally. In addition, Chaetothyriales comprise species with aquatic, rock-inhabiting, ant-associated, and mycoparasitic life-styles, as well as species that tolerate toxic compounds, suggesting a high degree of versatile extremotolerance. To understand their biology and divergent niche occupation, we sequenced and annotated a set of 23 genomes of main the human opportunists within the Chaetothyriales as well as related environmental species. Our analyses included fungi with diverse life-styles, namely opportunistic pathogens and closely related saprobes, to identify genomic adaptations related to pathogenesis. Furthermore, ecological preferences of Chaetothyriales were analysed, in conjuncture with the order-level phylogeny based on conserved ribosomal genes. General characteristics, phylogenomic relationships, transposable elements, sex-related genes, protein family evolution, genes related to protein degradation (MEROPS), carbohydrate-active enzymes (CAZymes), melanin synthesis and secondary metabolism were investigated and compared between species. Genome assemblies varied from 25.81 Mb (Capronia coronata) to 43.03 Mb (Cladophialophora immunda). The bantiana-clade contained the highest number of predicted genes (12 817 on average) as well as larger genomes. We found a low content of mobile elements, with DNA transposons from Tc1/Mariner superfamily being the most abundant across analysed species. Additionally, we identified a reduction of carbohydrate degrading enzymes, specifically many of the Glycosyl Hydrolase (GH) class, while most of the Pectin Lyase (PL) genes were lost in etiological agents of chromoblastomycosis and phaeohyphomycosis. An expansion was found in protein degrading peptidase enzyme families S12 (serine-type D-Ala-D-Ala carboxypeptidases) and M38 (isoaspartyl dipeptidases). Based on genomic information, a wide range of abilities of melanin biosynthesis was revealed; genes related to metabolically distinct DHN, DOPA and pyomelanin pathways were identified. The MAT (MAting Type) locus and other sex-related genes were recognized in all 23 black fungi. Members of the asexual genera Fonsecaea and Cladophialophora appear to be heterothallic with a single copy of either MAT-1-1 or MAT-1-2 in each individual. All Capronia species are homothallic as both MAT1-1 and MAT1-2 genes were found in each single genome. The genomic synteny of the MAT-locus flanking genes (SLA2-APN2-COX13) is not conserved in black fungi as is commonly observed in Eurotiomycetes, indicating a unique genomic context for MAT in those species. The heterokaryon (het) genes expansion associated with the low selective pressure at the MAT-locus suggests that a parasexual cycle may play an important role in generating diversity among those fungi.
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Affiliation(s)
- M.M. Teixeira
- Division of Pathogen Genomics, Translational Genomics Research Institute (TGen), Flagstaff, AZ, USA
- Department of Cell Biology, University of Brasília, Brasilia, Brazil
| | - L.F. Moreno
- Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands
- Department of Basic Pathology, Federal University of Paraná State, Curitiba, PR, Brazi1
- Institute of Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
| | - B.J. Stielow
- Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands
| | - A. Muszewska
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - M. Hainaut
- Université Aix-Marseille (CNRS), Marseille, France
| | - L. Gonzaga
- The National Laboratory for Scientific Computing (LNCC), Petropolis, Brazil
| | | | - J.S.L. Patané
- Department of Biochemistry, University of São Paulo, Brazil
| | - M. Priest
- Broad Institute of MIT and Harvard, Cambridge, USA
| | - R. Souza
- The National Laboratory for Scientific Computing (LNCC), Petropolis, Brazil
| | - S. Young
- Broad Institute of MIT and Harvard, Cambridge, USA
| | - K.S. Ferreira
- Department of Biological Sciences, Federal University of São Paulo, Diadema, SP, Brazil
| | - Q. Zeng
- Broad Institute of MIT and Harvard, Cambridge, USA
| | - M.M.L. da Cunha
- Núcleo Multidisciplinar de Pesquisa em Biologia UFRJ-Xerém-NUMPEX-BIO, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - A. Gladki
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - B. Barker
- Division of Pathogen Genomics, Translational Genomics Research Institute (TGen), Flagstaff, AZ, USA
| | - V.A. Vicente
- Department of Basic Pathology, Federal University of Paraná State, Curitiba, PR, Brazi1
| | - E.M. de Souza
- Department of Biochemistry and Molecular Biology, Federal University of Paraná, Curitiba, PR, Brazil
| | - S. Almeida
- Department of Clinical and Toxicological Analysis, University of São Paulo, São Paulo, SP, Brazil
| | - B. Henrissat
- Université Aix-Marseille (CNRS), Marseille, France
| | - A.T.R. Vasconcelos
- The National Laboratory for Scientific Computing (LNCC), Petropolis, Brazil
| | - S. Deng
- Shanghai Institute of Medical Mycology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - H. Voglmayr
- Department of Systematic and Evolutionary Botany, University of Vienna, Vienna, Austria
| | - T.A.A. Moussa
- Biological Sciences Department, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
- Botany and Microbiology Department, Faculty of Science, Cairo University, Giza, Egypt
| | - A. Gorbushina
- Federal Institute for Material Research and Testing (BAM), Berlin, Germany
| | - M.S.S. Felipe
- Department of Cell Biology, University of Brasília, Brasilia, Brazil
| | - C.A. Cuomo
- Broad Institute of MIT and Harvard, Cambridge, USA
| | - G. Sybren de Hoog
- Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands
- Department of Basic Pathology, Federal University of Paraná State, Curitiba, PR, Brazi1
- Institute of Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
- Biological Sciences Department, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
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DuBois JC, Smulian AG. Sterol Regulatory Element Binding Protein (Srb1) Is Required for Hypoxic Adaptation and Virulence in the Dimorphic Fungus Histoplasma capsulatum. PLoS One 2016; 11:e0163849. [PMID: 27711233 PMCID: PMC5053422 DOI: 10.1371/journal.pone.0163849] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2015] [Accepted: 09/08/2016] [Indexed: 01/12/2023] Open
Abstract
The Histoplasma capsulatum sterol regulatory element binding protein (SREBP), Srb1 is a member of the basic helix-loop-helix (bHLH), leucine zipper DNA binding protein family of transcription factors that possess a unique tyrosine (Y) residue instead of an arginine (R) residue in the bHLH region. We have determined that Srb1 message levels increase in a time dependent manner during growth under oxygen deprivation (hypoxia). To further understand the role of Srb1 during infection and hypoxia, we silenced the gene encoding Srb1 using RNA interference (RNAi); characterized the resulting phenotype, determined its response to hypoxia, and its ability to cause disease within an infected host. Silencing of Srb1 resulted in a strain of H. capsulatum that is incapable of surviving in vitro hypoxia. We found that without complete Srb1 expression, H. capsulatum is killed by murine macrophages and avirulent in mice given a lethal dose of yeasts. Additionally, silencing Srb1 inhibited the hypoxic upregulation of other known H. capsulatum hypoxia-responsive genes (HRG), and genes that encode ergosterol biosynthetic enzymes. Consistent with these regulatory functions, Srb1 silenced H. capsulatum cells were hypersensitive to the antifungal azole drug itraconazole. These data support the theory that the H. capsulatum SREBP is critical for hypoxic adaptation and is required for H. capsulatum virulence.
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Affiliation(s)
- Juwen C. DuBois
- Department of Pathology and Laboratory Medicine, University of Cincinnati, Cincinnati, Ohio, United States of America
- Cincinnati VA Medical Center, Cincinnati, Ohio, United States of America
| | - A. George Smulian
- Cincinnati VA Medical Center, Cincinnati, Ohio, United States of America
- Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, United States of America
- * E-mail:
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12
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Sagatova AA, Keniya MV, Wilson RK, Sabherwal M, Tyndall JDA, Monk BC. Triazole resistance mediated by mutations of a conserved active site tyrosine in fungal lanosterol 14α-demethylase. Sci Rep 2016; 6:26213. [PMID: 27188873 PMCID: PMC4870556 DOI: 10.1038/srep26213] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 04/25/2016] [Indexed: 12/27/2022] Open
Abstract
Emergence of fungal strains showing resistance to triazole drugs can make treatment of fungal disease problematic. Triazole resistance can arise due to single mutations in the drug target lanosterol 14α-demethylase (Erg11p/CYP51). We have determined how commonly occurring single site mutations in pathogenic fungi affect triazole binding using Saccharomyces cerevisiae Erg11p (ScErg11p) as a target surrogate. The mutations Y140F/H were introduced into full-length hexahistidine-tagged ScErg11p. Phenotypes and high-resolution X-ray crystal structures were determined for the mutant enzymes complexed with short-tailed (fluconazole and voriconazole) or long-tailed (itraconazole and posaconazole) triazoles and wild type enzyme complexed with voriconazole. The mutations disrupted a water-mediated hydrogen bond network involved in binding of short-tailed triazoles, which contain a tertiary hydroxyl not present in long-tailed triazoles. This appears to be the mechanism by which resistance to these short chain azoles occurs. Understanding how these mutations affect drug affinity will aid the design of azoles that overcome resistance.
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Affiliation(s)
- Alia A Sagatova
- Sir John Walsh Research Institute, University of Otago, Dunedin, New Zealand
| | - Mikhail V Keniya
- Sir John Walsh Research Institute, University of Otago, Dunedin, New Zealand
| | - Rajni K Wilson
- Sir John Walsh Research Institute, University of Otago, Dunedin, New Zealand
| | - Manya Sabherwal
- Sir John Walsh Research Institute, University of Otago, Dunedin, New Zealand
| | - Joel D A Tyndall
- New Zealand's National School of Pharmacy, University of Otago, Dunedin, New Zealand
| | - Brian C Monk
- Sir John Walsh Research Institute, University of Otago, Dunedin, New Zealand.,Department of Oral Sciences, University of Otago, Dunedin, New Zealand
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13
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Alvarez-Rueda N, Fleury A, Logé C, Pagniez F, Robert E, Morio F, Le Pape P. The amino acid substitution N136Y in Candida albicans sterol 14alpha-demethylase is involved in fluconazole resistance. Med Mycol 2016; 54:764-775. [PMID: 27143634 DOI: 10.1093/mmy/myw023] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2015] [Accepted: 03/24/2016] [Indexed: 12/22/2022] Open
Abstract
Resistance to fluconazole antifungal is an ongoing impediment to a successful treatment of Candida albicans infections. One of the most prevalent mechanisms leading to azole resistance is genetic alterations of the 14α-demethylase, the target of azole antifungals, through point mutations. Site-directed mutagenesis and molecular modeling of 14α-demethylase rationalize biological data about the role of protein substitutions in the azole treatment failure. In this work, we investigated the role of N136Y substitution by site-directed mutagenesis into Pichia pastoris guided by structural analysis. Single amino acid substitutions were created by site-directed mutagenesis into P. pastoris with C. albicans ERG11 gene as template. In vitro susceptibility of P. pastoris transformants expressing wild-type and mutants to azole compounds was determined by CLSI M27-A2 and spot agar methods. The fluconazole effect on ergosterol biosynthesis was analyzed by gas chromatography-mass spectrometry. By microdilution and spot tests, N136Y transformants showed a reduced in vitro susceptibility to fluconazole compared to wild-type controls. As expected, ergosterol/lanosterol ratios were higher in N136Y transformants compared to the wild-type controls after treatment with fluconazole. Molecular modeling suggests that residue Asn136 located within the first mutation hot spot, could play a role during heme and azole binding. These results provide new insights into the structural basis for 14α-demethylase-azole interaction and could guide the design of novel azole antifungals.
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Affiliation(s)
| | - Audrey Fleury
- Département de Parasitologie et de Mycologie Médicale
| | - Cédric Logé
- Laboratoire de Chimie Thérapeutique, Université de Nantes, Nantes Atlantique Universités, EA1155 - IICiMed, UFR des Sciences Pharmaceutiques et Biologiques, France
| | | | | | - Florent Morio
- Département de Parasitologie et de Mycologie Médicale.,Laboratoire de Parasitologie-Mycologie, CHU de Nantes, Nantes, France
| | - Patrice Le Pape
- Département de Parasitologie et de Mycologie Médicale.,Laboratoire de Parasitologie-Mycologie, CHU de Nantes, Nantes, France
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14
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Ohk SO, Park HG, Lee H, Kwon YJ, Kim BJ, Kim D, Chun YJ. Heterologous expression and characterization of CYP61A1 from dandruff-causing Malassezia globosa. Protein Expr Purif 2015; 114:89-94. [PMID: 26160660 DOI: 10.1016/j.pep.2015.07.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Revised: 07/04/2015] [Accepted: 07/04/2015] [Indexed: 11/17/2022]
Abstract
Malassezia globosa is pathogenic fungus that causes skin disorders including dandruff in humans. Many yeast cytochrome CYP enzymes are involved in the biosynthesis of sterols and are considered major targets of azole antifungal agents. Here, we report on the expression and characterization of the MGL_0310 gene product (CYP61A1), a sterol C-22 desaturase in M. globosa. The open reading frame of the CYP61A1 gene was amplified by PCR from M. globosa CBS 7966 genomic DNA and cloned into a pCW vector. The CYP61A1 gene was heterologously expressed in Escherichia coli and purified using a Ni(2+)-NTA affinity column. The purified CYP61A1 protein exhibited a CO-difference spectrum typical of CYPs with a maximum absorption at 452nm. Binding spectral titration with β-sitosterol and campesterol demonstrated the type I binding mode with an increase at 411nm and a decrease at 432nm. The calculated Kd values are 5.4±0.6μM and 6.1±1.0μM for β-sitosterol and campesterol, respectively. No metabolic product, however, was observed in the CYP61A1-supported enzyme reaction with these sterols. The purified CYP61A1 protein exhibited tight binding to azole agents, suggesting that this enzyme may be a target for the pathogenic M. globosa fungus. Moreover, several fatty acids were found to bind to CYP61A1, indicating that the architecture of the enzyme includes a relatively large active site space. This study provides new insight into the biosynthesis of fungal sterols in M. globosa and a basis for the development of antifungal as potential therapeutic agents to treat dandruff.
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Affiliation(s)
- Seul-Ong Ohk
- College of Pharmacy, Chung-Ang University, Seoul 156-756, Republic of Korea
| | - Hyoung-Goo Park
- Department of Biological Sciences, Konkuk University, Seoul 143-701, Republic of Korea
| | - Hwayoun Lee
- Department of Biological Sciences, Konkuk University, Seoul 143-701, Republic of Korea
| | - Yeo-Jung Kwon
- College of Pharmacy, Chung-Ang University, Seoul 156-756, Republic of Korea
| | - Beom Joon Kim
- Department of Dermatology, College of Medicine, Chung-Ang University, Seoul 156-755, Republic of Korea
| | - Donghak Kim
- Department of Biological Sciences, Konkuk University, Seoul 143-701, Republic of Korea.
| | - Young-Jin Chun
- College of Pharmacy, Chung-Ang University, Seoul 156-756, Republic of Korea.
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15
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Structural Insights into Binding of the Antifungal Drug Fluconazole to Saccharomyces cerevisiae Lanosterol 14α-Demethylase. Antimicrob Agents Chemother 2015; 59:4982-9. [PMID: 26055382 DOI: 10.1128/aac.00925-15] [Citation(s) in RCA: 105] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 06/04/2015] [Indexed: 01/21/2023] Open
Abstract
Infections by fungal pathogens such as Candida albicans and Aspergillus fumigatus and their resistance to triazole drugs are major concerns. Fungal lanosterol 14α-demethylase belongs to the CYP51 class in the cytochrome P450 superfamily of enzymes. This monospanning bitopic membrane protein is involved in ergosterol biosynthesis and is the primary target of azole antifungal drugs, including fluconazole. The lack of high-resolution structural information for this drug target from fungal pathogens has been a limiting factor for the design of modified triazole drugs that will overcome resistance. Here we report the X-ray structure of full-length Saccharomyces cerevisiae lanosterol 14α-demethylase in complex with fluconazole at a resolution of 2.05 Å. This structure shows the key interactions involved in fluconazole binding and provides insight into resistance mechanisms by revealing a water-mediated hydrogen bonding network between the drug and tyrosine 140, a residue frequently found mutated to histidine or phenylalanine in resistant clinical isolates.
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16
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Hu L, Du X, Li T, Song Y, Zai S, Hu X, Zhang X, Li M. Genetic and phenotypic characterization of Candida albicans strains isolated from infectious disease patients in Shanghai. J Med Microbiol 2015; 64:74-83. [PMID: 25351710 DOI: 10.1099/jmm.0.080200-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Lvyin Hu
- Department of Clinical Laboratory, Shanghai Public Health Clinical Center, Fudan University, No. 2901 Cao Lang Rd, Shanghai, PR China
- Department of Laboratory Medicine, Huashan Hospital, Shanghai Medical College, Fudan University, 12 Central Urumqi Road, Shanghai, PR China
| | - Xin Du
- Department of Laboratory Medicine, Huashan Hospital, Shanghai Medical College, Fudan University, 12 Central Urumqi Road, Shanghai, PR China
| | - Tianming Li
- Department of Laboratory Medicine, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, PR China
| | - Yan Song
- Department of Laboratory Medicine, Huashan Hospital, Shanghai Medical College, Fudan University, 12 Central Urumqi Road, Shanghai, PR China
| | - Shubei Zai
- Department of Clinical Laboratory, Shanghai Public Health Clinical Center, Fudan University, No. 2901 Cao Lang Rd, Shanghai, PR China
| | - Xiangnan Hu
- Department of Clinical Laboratory, Shanghai Public Health Clinical Center, Fudan University, No. 2901 Cao Lang Rd, Shanghai, PR China
| | - Xiaonan Zhang
- Research Unit, Shanghai Public Health Clinical Center, Fudan University, No. 2901 Cao Lang Rd, Shanghai, PR China
| | - Min Li
- Department of Laboratory Medicine, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, PR China
- Department of Laboratory Medicine, Huashan Hospital, Shanghai Medical College, Fudan University, 12 Central Urumqi Road, Shanghai, PR China
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17
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Genomic and transcriptomic analyses of the medicinal fungus Antrodia cinnamomea for its metabolite biosynthesis and sexual development. Proc Natl Acad Sci U S A 2014; 111:E4743-52. [PMID: 25336756 DOI: 10.1073/pnas.1417570111] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Antrodia cinnamomea, a polyporus mushroom of Taiwan, has long been used as a remedy for cancer, hypertension, and hangover, with an annual market of over $100 million (US) in Taiwan. We obtained a 32.15-Mb genome draft containing 9,254 genes. Genome ontology enrichment and pathway analyses shed light on sexual development and the biosynthesis of sesquiterpenoids, triterpenoids, ergostanes, antroquinonol, and antrocamphin. We identified genes differentially expressed between mycelium and fruiting body and 242 proteins in the mevalonate pathway, terpenoid pathways, cytochrome P450s, and polyketide synthases, which may contribute to the production of medicinal secondary metabolites. Genes of secondary metabolite biosynthetic pathways showed expression enrichment for tissue-specific compounds, including 14-α-demethylase (CYP51F1) in fruiting body for converting lanostane to ergostane triterpenoids, coenzymes Q (COQ) for antroquinonol biosynthesis in mycelium, and polyketide synthase for antrocamphin biosynthesis in fruiting body. Our data will be useful for developing a strategy to increase the production of useful metabolites.
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18
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de Oliveira Ceita G, Vilas-Boas LA, Castilho MS, Carazzolle MF, Pirovani CP, Selbach-Schnadelbach A, Gramacho KP, Ramos PIP, Barbosa LV, Pereira GAG, Góes-Neto A. Analysis of the ergosterol biosynthesis pathway cloning, molecular characterization and phylogeny of lanosterol 14 α-demethylase (ERG11) gene of Moniliophthora perniciosa. Genet Mol Biol 2014; 37:683-93. [PMID: 25505843 PMCID: PMC4261968 DOI: 10.1590/s1415-47572014005000017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Accepted: 06/04/2014] [Indexed: 11/22/2022] Open
Abstract
The phytopathogenic fungus Moniliophthora perniciosa (Stahel) Aime & Philips-Mora, causal agent of witches' broom disease of cocoa, causes countless damage to cocoa production in Brazil. Molecular studies have attempted to identify genes that play important roles in fungal survival and virulence. In this study, sequences deposited in the M. perniciosa Genome Sequencing Project database were analyzed to identify potential biological targets. For the first time, the ergosterol biosynthetic pathway in M. perniciosa was studied and the lanosterol 14α-demethylase gene (ERG11) that encodes the main enzyme of this pathway and is a target for fungicides was cloned, characterized molecularly and its phylogeny analyzed. ERG11 genomic DNA and cDNA were characterized and sequence analysis of the ERG11 protein identified highly conserved domains typical of this enzyme, such as SRS1, SRS4, EXXR and the heme-binding region (HBR). Comparison of the protein sequences and phylogenetic analysis revealed that the M. perniciosa enzyme was most closely related to that of Coprinopsis cinerea.
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Affiliation(s)
- Geruza de Oliveira Ceita
- Laboratório de Pesquisa em Microbiologia,
Departamento de Ciências Biológicas,
Universidade Estadual de Feira de Santana,
Feira de Santana,
BA,
Brazil
- Laboratório de Biologia Molecular,
Instituto de Biologia,
Departamento de Biologia Geral,
Universidade Federal da Bahia,
Salvador,
BA,
Brazil
| | - Laurival Antônio Vilas-Boas
- Centro de Ciências Biológicas,
Departamento de Biologia Geral,
Universidade Estadual de Londrina,
Londrina,
PR,
Brazil
| | - Marcelo Santos Castilho
- Laboratório de Bioinformática e Modelagem Molecular,
Departamento do Medicamento,
Faculdade de Farmácia,
Universidade Federal da Bahia,
Salvador,
BA,
Brazil
| | - Marcelo Falsarella Carazzolle
- Laboratório de Genômica e Proteômica,
Departamento de Genética e Evolução,
Universidade Estadual de Campinas,
Campinas,
SP,
Brazil
| | - Carlos Priminho Pirovani
- Centro de Biotecnologia e Genética,
Departamento de Ciências Biológicas,
Universidade Estadual de Santa Cruz,
Ilhéus,
BA,
Brazil
| | - Alessandra Selbach-Schnadelbach
- Laboratório de Biologia Molecular,
Instituto de Biologia,
Departamento de Biologia Geral,
Universidade Federal da Bahia,
Salvador,
BA,
Brazil
| | - Karina Peres Gramacho
- Laboratório de Fitopatologia Molecular,
Centro de Pesquisas do Cacau,
Ilhéus,
BA,
Brazil
| | - Pablo Ivan Pereira Ramos
- Laboratório de Biologia Molecular,
Instituto de Biologia,
Departamento de Biologia Geral,
Universidade Federal da Bahia,
Salvador,
BA,
Brazil
| | - Luciana Veiga Barbosa
- Laboratório de Biologia Molecular,
Instituto de Biologia,
Departamento de Biologia Geral,
Universidade Federal da Bahia,
Salvador,
BA,
Brazil
| | | | - Aristóteles Góes-Neto
- Laboratório de Pesquisa em Microbiologia,
Departamento de Ciências Biológicas,
Universidade Estadual de Feira de Santana,
Feira de Santana,
BA,
Brazil
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19
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Alcazar-Fuoli L, Mellado E. Current status of antifungal resistance and its impact on clinical practice. Br J Haematol 2014; 166:471-84. [PMID: 24749533 DOI: 10.1111/bjh.12896] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 03/17/2014] [Indexed: 11/30/2022]
Abstract
Mortality linked to invasive fungal diseases remains very high despite the availability of novel antifungals and new therapeutic strategies. Candida albicans and Aspergillus fumigatus account for most invasive mycosis produced by yeast or moulds, respectively. Other Candida non-albicans are increasingly being reported and newly emerging, as well as cryptic, filamentous fungi often cause disseminated infections in immunocompromised hosts. Management of invasive fungal infections is becoming a challenge as emerging fungal pathogens generally show poor response to many antifungals. The ability of reference antifungal susceptibility testing methods to detect emerging resistance patterns, together with the molecular characterization of antifungal resistance mechanisms, are providing useful information to optimize the effectiveness of antifungal therapy. The current status of antifungal resistance epidemiology with special emphasis on the molecular resistant mechanisms that have been described in the main pathogenic fungal species are reviewed.
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Affiliation(s)
- Laura Alcazar-Fuoli
- Mycology Reference Laboratory, Centro Nacional de Microbiologia, Instituto de Salud Carlos III, Madrid, Spain
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20
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Lee H, Kim JH, Han S, Lim YR, Park HG, Chun YJ, Park SW, Kim D. Directed-evolution analysis of human cytochrome P450 2A6 for enhanced enzymatic catalysis. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2014; 77:1409-1418. [PMID: 25343290 DOI: 10.1080/15287394.2014.951757] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Cytochrome P450 2A6 (P450 2A6) is the major enzyme responsible for the oxidation of coumarin, nicotine, and tobacco-specific nitrosamines in human liver. In this study, the catalytic turnover of coumarin oxidation was improved by directed-evolution analysis of P450 2A6 enzyme. A random mutant library was constructed using error-prone polymerase chain reaction (PCR) of the open reading frame of the P450 2A6 gene and individual mutant clones were screened for improved catalytic activity in analysis of fluorescent coumarin 7-hydroxylation. Four consecutive rounds of random mutagenesis and screening were performed and catalytically enhanced mutants were selected in each round of screening. The selected mutants showed the sequentially accumulated mutations of amino acid residues of P450 2A6: B1 (F209S), C1 (F209S, S369G), D1 (F209S, S369G, E277K), and E1 (F209S, S369G, E277K, A10V). E1 mutants displayed approximately 13-fold increased activity based on fluorescent coumarin hydroxylation assays at bacterial whole cell level. Steady-state kinetic parameters for coumarin 7-hydroxylation and nicotine oxidation were measured in purified mutant enzymes and indicated catalytic turnover numbers (kcat) of selected mutants were enhanced up to sevenfold greater than wild-type P450 2A6. However, all mutants displayed elevated Km values and therefore catalytic efficiencies (kcat/Km) were not improved. The increase in Km values was partially attributed to reduction in substrate binding affinities measured in the analysis of substrate binding titration. The structural analysis of P450 2A6 indicates that F209S mutation is sufficient to affect direct interaction of substrate at the active site.
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Affiliation(s)
- Hwayoun Lee
- a Department of Biological Sciences , Konkuk University , Seoul , Korea
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21
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Candida tropicalis antifungal cross-resistance is related to different azole target (Erg11p) modifications. Antimicrob Agents Chemother 2013; 57:4769-81. [PMID: 23877676 DOI: 10.1128/aac.00477-13] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Candida tropicalis ranks between third and fourth among Candida species most commonly isolated from clinical specimens. Invasive candidiasis and candidemia are treated with amphotericin B or echinocandins as first-line therapy, with extended-spectrum triazoles as acceptable alternatives. Candida tropicalis is usually susceptible to all antifungal agents, although several azole drug-resistant clinical isolates are being reported. However, C. tropicalis resistant to amphotericin B is uncommon, and only a few strains have reliably demonstrated a high level of resistance to this agent. The resistance mechanisms operating in C. tropicalis strains isolated from clinical samples showing resistance to azole drugs alone or with amphotericin B cross-resistance were elucidated. Antifungal drug resistance was related to mutations of the azole target (Erg11p) with or without alterations of the ergosterol biosynthesis pathway. The antifungal drug resistance shown in vitro correlated very well with the results obtained in vivo using the model host Galleria mellonella. Using this panel of strains, the G. mellonella model system was validated as a simple, nonmammalian minihost model that can be used to study in vitro-in vivo correlation of antifungals in C. tropicalis. The development in C. tropicalis of antifungal drug resistance with different mechanisms during antifungal treatment has potential clinical impact and deserves specific prospective studies.
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22
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Evaluation of structural features in fungal cytochromes P450 predicted to rule catalytic diversification. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2013; 1834:205-20. [DOI: 10.1016/j.bbapap.2012.09.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Revised: 09/17/2012] [Accepted: 09/18/2012] [Indexed: 01/11/2023]
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23
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Han S, Choi S, Chun YJ, Yun CH, Lee CH, Shin HJ, Na HS, Chung MW, Kim D. Functional characterization of allelic variants of polymorphic human cytochrome P450 2A6 (CYP2A6*5, *7, *8, *18, *19, and *35). Biol Pharm Bull 2012; 35:394-9. [PMID: 22382327 DOI: 10.1248/bpb.35.394] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cytochrome P450 2A6 (CYP2A6) catalyzes important metabolic reactions of many xenobiotic compounds, including coumarin, nicotine, cotinine, and clinical drugs. Genetic polymorphisms of CYP2A6 can influence its metabolic activities. This study analyzed the functional activities of six CYP2A6 allelic variants (CYP2A6*5, *7, *8, *18, *19, and *35) containing nonsynonymous single-nucleotide polymorphisms. Recombinant variant enzymes of CYP2A6*7, *8, *18, *19, and *35 were successfully expressed in Escherichia coli and purified. However, a P450 holoenzyme spectrum was not detected for the CYP2A6*5 allelic variant (G479V). Structural analysis shows that the G479V mutation may alter the interaction between the A helix and the F-G helices. Enzyme kinetic analyses indicated that the effects of mutations in CYP2A6 allelic variants on drug metabolism are dependent on the substrates. In the case of coumarin 7-hydroxylation, CYP2A6*8 and *35 displayed increased K(m) values whereas CYP2A6*18 and *19 showed decreased k(cat) values, which resulted in lower catalytic efficiencies (k(cat)/K(m)). In the case of nicotine 5-oxidation, the CYP2A6*19 variant exhibited an increased K(m) value, whereas CYP2A6*18 and *35 showed much greater decreases in k(cat) values. These results suggest that individuals carrying these allelic variants are likely to have different metabolisms for different CYP2A6 substrates. Functional characterization of these allelic variants of CYP2A6 can help determine the importance of CYP2A6 polymorphisms in the metabolism of many clinical drugs.
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Affiliation(s)
- Songhee Han
- Department of Biological Sciences, Konkuk University, Seoul, Korea
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24
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Becher R, Wirsel SGR. Fungal cytochrome P450 sterol 14α-demethylase (CYP51) and azole resistance in plant and human pathogens. Appl Microbiol Biotechnol 2012; 95:825-40. [PMID: 22684327 DOI: 10.1007/s00253-012-4195-9] [Citation(s) in RCA: 149] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Revised: 05/18/2012] [Accepted: 05/19/2012] [Indexed: 01/18/2023]
Abstract
Azoles have been applied widely to combat pathogenic fungi in medicine and agriculture and, consequently, loss of efficacy has occurred in populations of some species. Often, but not always, resistance was found to result from amino acid substitutions in the molecular target of azoles, 14α-sterol demethylase (CYP51 syn. ERG11). This review summarizes CYP51 function, evolution, and structure. Furthermore, we compare the occurrence and contribution of CYP51 substitutions to azole resistance in clinical and field isolates of important fungal pathogens. Although no crystal structure is available yet for any fungal CYP51, homology modeling using structures from other origins as template allowed deducing models for fungal orthologs. These models served to map amino acid changes known from clinical and field isolates. We conclude with describing the potential consequences of these changes on the topology of the protein to explain CYP51-based azole resistance. Knowledge gained from molecular modeling and resistance research will help to develop novel azole structures.
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Affiliation(s)
- Rayko Becher
- Institut für Agrar- und Ernährungswissenschaften, Naturwissenschaftliche Fakultät III, Martin-Luther-Universität Halle-Wittenberg, Betty-Heimann-Strasse 3, Halle (Saale), Germany
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25
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S279 point mutations in Candida albicans Sterol 14-α demethylase (CYP51) reduce in vitro inhibition by fluconazole. Antimicrob Agents Chemother 2012; 56:2099-107. [PMID: 22252802 DOI: 10.1128/aac.05389-11] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The effects of S279F and S279Y point mutations in Candida albicans CYP51 (CaCYP51) on protein activity and on substrate (lanosterol) and azole antifungal binding were investigated. Both S279F and S279Y mutants bound lanosterol with 2-fold increased affinities (K(s), 7.1 and 8.0 μM, respectively) compared to the wild-type CaCYP51 protein (K(s), 13.5 μM). The S279F and S279Y mutants and the wild-type CaCYP51 protein bound fluconazole, voriconazole, and itraconazole tightly, producing typical type II binding spectra. However, the S279F and S279Y mutants had 4- to 5-fold lower affinities for fluconazole, 3.5-fold lower affinities for voriconazole, and 3.5- to 4-fold lower affinities for itraconazole than the wild-type CaCYP51 protein. The S279F and S279Y mutants gave 2.3- and 2.8-fold higher 50% inhibitory concentrations (IC₅₀s) for fluconazole in a CYP51 reconstitution assay than the wild-type protein did. The increased fluconazole resistance conferred by the S279F and S279Y point mutations appeared to be mediated through a combination of a higher affinity for substrate and a lower affinity for fluconazole. In addition, lanosterol displaced fluconazole from the S279F and S279Y mutants but not from the wild-type protein. Molecular modeling of the wild-type protein indicated that the oxygen atom of S507 interacts with the second triazole ring of fluconazole, assisting in orientating fluconazole so that a more favorable binding conformation to heme is achieved. In contrast, in the two S279 mutant proteins, this S507-fluconazole interaction is absent, providing an explanation for the higher K(d) values observed.
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