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Toffaletti DL, Tenor JL, Perfect JR. Biolistic Transformation of Cryptococcus neoformans. Methods Mol Biol 2024; 2775:59-79. [PMID: 38758311 DOI: 10.1007/978-1-0716-3722-7_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/18/2024]
Abstract
Biolistic transformation of Cryptococcus neoformans is used as a molecular tool to genetically alter or delete targeted genes. The DNA is introduced into the yeast on DNA-coated gold beads by a helium shock wave produced using a biolistic particle system. The procedure often involves insertion of a dominant selectable marker into the desired site by homologous recombination. To increase the likelihood of homologous recombination, large fragments of overlapping DNA are used. The two most used dominant selectable markers are nourseothricin and Geneticin. With the need to generate multiple gene deletions in the same strain, there are recyclable marker systems, such as the bacteriophage P1 Cre-loxP system or CRISPR that provide additional useful molecular tools. While newer strategies exist to generate deletions and introduce markers and other gene modifications, biolistic transformation has remained a viable tool to facilitate the construction of genetically modified yeast strains. This chapter provides a working protocol on how to delete and restore a gene in C. neoformans.
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Affiliation(s)
- Dena L Toffaletti
- Duke University School of Medicine, Department of Medicine, Division of Infectious Diseases, Durham, NC, USA
| | - Jennifer L Tenor
- Duke University School of Medicine, Department of Medicine, Division of Infectious Diseases, Durham, NC, USA
| | - John R Perfect
- Duke University School of Medicine, Department of Medicine, Division of Infectious Diseases, Durham, NC, USA.
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Wang Y, Lin R, Liu M, Wang S, Chen H, Zeng W, Nie X, Wang S. N-Myristoyltransferase, a Potential Antifungal Candidate Drug-Target for Aspergillus flavus. Microbiol Spectr 2023; 11:e0421222. [PMID: 36541770 PMCID: PMC9927591 DOI: 10.1128/spectrum.04212-22] [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: 10/15/2022] [Accepted: 11/28/2022] [Indexed: 12/24/2022] Open
Abstract
The filamentous fungus Aspergillus flavus causes devastating diseases not only to cash crops but also to humans by secreting a series of secondary metabolites called aflatoxins. In the cotranslational or posttranslational process, N-myristoyltransferase (Nmt) is a crucial enzyme that catalyzes the myristate group from myristoyl-coenzyme A (myristoyl-CoA) to the N terminus or internal glycine residue of a protein by forming a covalent bond. Members of the Nmt family execute a diverse range of biological functions across a broad range of fungi. However, the underlying mechanism of AflNmt action in the A. flavus life cycle is unclear, particularly during the growth, development, and secondary metabolic synthesis stages. In the present study, AlfNmt was found to be essential for the development of spore and sclerotia, based on the regulation of the xylose-inducible promoter. AflNmt, located in the cytoplasm of A. flavus, is also involved in modulating aflatoxin (AFB1) in A. flavus, which has not previously been reported in Aspergillus spp. In addition, we purified, characterized, and crystallized the recombinant AflNmt protein (rAflNmt) from the Escherichia coli expression system. Interestingly, the crystal structure of rAlfNmt is moderately different from the models predicted by AlphaFold2 in the N-terminal region, indicating the limitations of machine-learning prediction. In conclusion, these results provide a molecular basis for the functional role of AflNmt in A. flavus and structural insights concerning protein prediction. IMPORTANCE As an opportunistic pathogen, A. flavus causes crop loss due to fungal growth and mycotoxin contamination. Investigating the role of virulence factors during infection and searching for novel drug targets have been popular scientific topics in the field of fungal control. Nmt has become a potential target in some organisms. However, whether Nmt is involved in the developmental stages of A. flavus and aflatoxin synthesis, and whether AlfNmt is an ideal target for structure-based drug design, remains unclear. This study systematically explored and identified the role of AlfNmt in the development of spore and sclerotia, especially in aflatoxin biosynthesis. Moreover, although there is not much difference between the AflNmt model predicted using the AlphaFold2 technique and the structure determined using the X-ray method, current AI prediction models may not be suitable for structure-based drug development. There is still room for further improvements in protein prediction.
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Affiliation(s)
- Yu Wang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
- School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
| | - Ranxun Lin
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
- School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
| | - Mengxin Liu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
- School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
| | - Sen Wang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
- School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
| | - Hongyu Chen
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
- School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
| | - Wanlin Zeng
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
- School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
| | - Xinyi Nie
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
- School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
| | - Shihua Wang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
- School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
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Othman IM, Mahross MH, Gad-Elkareem MA, Rudrapal M, Gogoi N, Chetia D, Aouadi K, Snoussi M, Kadri A. Toward a treatment of antibacterial and antifungal infections: Design, synthesis and in vitro activity of novel arylhydrazothiazolylsulfonamides analogues and their insight of DFT, docking and molecular dynamic simulations. J Mol Struct 2021. [DOI: 10.1016/j.molstruc.2021.130862] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Liu W, Triplett L, Chen XL. Emerging Roles of Posttranslational Modifications in Plant-Pathogenic Fungi and Bacteria. ANNUAL REVIEW OF PHYTOPATHOLOGY 2021; 59:99-124. [PMID: 33909479 DOI: 10.1146/annurev-phyto-021320-010948] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Posttranslational modifications (PTMs) play crucial roles in regulating protein function and thereby control many cellular processes and biological phenotypes in both eukaryotes and prokaryotes. Several recent studies illustrate how plant fungal and bacterial pathogens use these PTMs to facilitate development, stress response, and host infection. In this review, we discuss PTMs that have key roles in the biological and infection processes of plant-pathogenic fungi and bacteria. The emerging roles of PTMs during pathogen-plant interactions are highlighted. We also summarize traditional tools and emerging proteomics approaches for PTM research. These discoveries open new avenues for investigating the fundamental infection mechanisms of plant pathogens and the discovery of novel strategies for plant disease control.
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Affiliation(s)
- Wende Liu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China;
| | - Lindsay Triplett
- Department of Plant Pathology and Ecology, The Connecticut Agricultural Experiment Station, New Haven, Connecticut 06511, USA;
| | - Xiao-Lin Chen
- State Key Laboratory of Agricultural Microbiology and Provincial Hubei Key Laboratory of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China;
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Molecular targets for antifungals in amino acid and protein biosynthetic pathways. Amino Acids 2021; 53:961-991. [PMID: 34081205 PMCID: PMC8241756 DOI: 10.1007/s00726-021-03007-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 05/17/2021] [Indexed: 01/22/2023]
Abstract
Fungi cause death of over 1.5 million people every year, while cutaneous mycoses are among the most common infections in the world. Mycoses vary greatly in severity, there are long-term skin (ringworm), nail or hair infections (tinea capitis), recurrent like vaginal candidiasis or severe, life-threatening systemic, multiorgan infections. In the last few years, increasing importance is attached to the health and economic problems caused by fungal pathogens. There is a growing need for improvement of the availability of antifungal drugs, decreasing their prices and reducing side effects. Searching for novel approaches in this respect, amino acid and protein biosynthesis pathways appear to be competitive. The route that leads from amino acid biosynthesis to protein folding and its activation is rich in enzymes that are descriptive of fungi. Blocking the action of those enzymes often leads to avirulence or growth inhibition. In this review, we want to trace the principal processes of fungi vitality. We present the data of genes encoding enzymes involved in amino acid and protein biosynthesis, potential molecular targets in antifungal chemotherapy, and describe the impact of inhibitors on fungal organisms.
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Suazo KF, Park KY, Distefano MD. A Not-So-Ancient Grease History: Click Chemistry and Protein Lipid Modifications. Chem Rev 2021; 121:7178-7248. [PMID: 33821625 DOI: 10.1021/acs.chemrev.0c01108] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Protein lipid modification involves the attachment of hydrophobic groups to proteins via ester, thioester, amide, or thioether linkages. In this review, the specific click chemical reactions that have been employed to study protein lipid modification and their use for specific labeling applications are first described. This is followed by an introduction to the different types of protein lipid modifications that occur in biology. Next, the roles of click chemistry in elucidating specific biological features including the identification of lipid-modified proteins, studies of their regulation, and their role in diseases are presented. A description of the use of protein-lipid modifying enzymes for specific labeling applications including protein immobilization, fluorescent labeling, nanostructure assembly, and the construction of protein-drug conjugates is presented next. Concluding remarks and future directions are presented in the final section.
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Affiliation(s)
- Kiall F Suazo
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Keun-Young Park
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Mark D Distefano
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
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7
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Wang P. Genetic Transformation in Cryptococcus Species. J Fungi (Basel) 2021; 7:jof7010056. [PMID: 33467426 PMCID: PMC7829943 DOI: 10.3390/jof7010056] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 01/11/2021] [Accepted: 01/13/2021] [Indexed: 12/26/2022] Open
Abstract
Genetic transformation plays an imperative role in our understanding of the biology in unicellular yeasts and filamentous fungi, such as Saccharomyces cerevisiae, Aspergillus nidulans, Cryphonectria parasitica, and Magnaporthe oryzae. It also helps to understand the virulence and drug resistance mechanisms of the pathogenic fungus Cryptococcus that causes cryptococcosis in health and immunocompromised individuals. Since the first attempt at DNA transformation in this fungus by Edman in 1992, various methods and techniques have been developed to introduce DNA into this organism and improve the efficiency of homology-mediated gene disruption. There have been many excellent summaries or reviews covering the subject. Here we highlight some of the significant achievements and additional refinements in the genetic transformation of Cryptococcus species.
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Affiliation(s)
- Ping Wang
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA
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Sugiura Y, Akiyama R, Tanaka S, Yano K, Kameoka H, Marui S, Saito M, Kawaguchi M, Akiyama K, Saito K. Myristate can be used as a carbon and energy source for the asymbiotic growth of arbuscular mycorrhizal fungi. Proc Natl Acad Sci U S A 2020; 117:25779-25788. [PMID: 32999061 PMCID: PMC7568319 DOI: 10.1073/pnas.2006948117] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Arbuscular mycorrhizal (AM) fungi, forming symbiotic associations with land plants, are obligate symbionts that cannot complete their natural life cycle without a host. The fatty acid auxotrophy of AM fungi is supported by recent studies showing that lipids synthesized by the host plants are transferred to the fungi, and that the latter lack genes encoding cytosolic fatty acid synthases. Therefore, to establish an asymbiotic cultivation system for AM fungi, we tried to identify the fatty acids that could promote biomass production. To determine whether AM fungi can grow on medium supplied with fatty acids or lipids under asymbiotic conditions, we tested eight saturated or unsaturated fatty acids (C12 to C18) and two β-monoacylglycerols. Only myristate (C14:0) led to an increase in the biomass of Rhizophagus irregularis, inducing extensive hyphal growth and formation of infection-competent secondary spores. However, such spores were smaller than those generated symbiotically. Furthermore, we demonstrated that R. irregularis can take up fatty acids in its branched hyphae and use myristate as a carbon and energy source. Myristate also promoted the growth of Rhizophagus clarus and Gigaspora margarita Finally, mixtures of myristate and palmitate accelerated fungal growth and induced a substantial change in fatty acid composition of triacylglycerol compared with single myristate application, although palmitate was not used as a carbon source for cell wall biosynthesis in this culture system. Our findings demonstrate that myristate boosts the asymbiotic growth of AM fungi and can also serve as a carbon and energy source.
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Affiliation(s)
- Yuta Sugiura
- Graduate School of Science and Technology, Shinshu University, Minamiminowa, 399-4598 Nagano, Japan
| | - Rei Akiyama
- Graduate School of Science and Technology, Shinshu University, Minamiminowa, 399-4598 Nagano, Japan
| | - Sachiko Tanaka
- Division of Symbiotic Systems, National Institute for Basic Biology, Okazaki, 444-0867 Aichi, Japan
| | - Koji Yano
- Division of Symbiotic Systems, National Institute for Basic Biology, Okazaki, 444-0867 Aichi, Japan
| | - Hiromu Kameoka
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai, 599-8531 Osaka, Japan
| | - Shiori Marui
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai, 599-8531 Osaka, Japan
| | - Masanori Saito
- Field Science Center, Graduate School of Agricultural Science, Tohoku University, Miyagi, 989-6711 Osaki, Japan
| | - Masayoshi Kawaguchi
- Division of Symbiotic Systems, National Institute for Basic Biology, Okazaki, 444-0867 Aichi, Japan
- Department of Basic Biology, School of Life Science, Graduate University for Advanced Studies, Okazaki, 444-0867 Aichi, Japan
| | - Kohki Akiyama
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai, 599-8531 Osaka, Japan
| | - Katsuharu Saito
- Faculty of Agriculture, Shinshu University, Minamiminowa, 399-4598 Nagano, Japan
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Kosciuk T, Lin H. N-Myristoyltransferase as a Glycine and Lysine Myristoyltransferase in Cancer, Immunity, and Infections. ACS Chem Biol 2020; 15:1747-1758. [PMID: 32453941 DOI: 10.1021/acschembio.0c00314] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Protein myristoylation, the addition of a 14-carbon saturated acyl group, is an abundant modification implicated in biological events as diverse as development, immunity, oncogenesis, and infections. N-Myristoyltransferase (NMT) is the enzyme that catalyzes this modification. Many elegant studies have established the rules guiding the catalysis including substrate amino acid sequence requirements with the indispensable N-terminal glycine, and a co-translational mode of action. Recent advances in technology such as the development of fatty acid analogs, small molecule inhibitors, and new proteomic strategies, allowed a deeper insight into the NMT activity and function. Here we focus on discussing recent work demonstrating that NMT is also a lysine myristoyltransferase, the enzyme's regulation by a previously unnoticed solvent channel, and the mechanism of NMT regulation by protein-protein interactions. We also summarize recent findings on NMT's role in cancer, immunity, and infections and the advances in pharmacological targeting of myristoylation. Our analyses highlight opportunities for further understanding and discoveries.
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Affiliation(s)
- Tatsiana Kosciuk
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853, United States
| | - Hening Lin
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
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du Plooy LM, Sebolai OM, Pohl CH, Albertyn J. Functional Characterization of Cryptococcal Genes: Then and Now. Front Microbiol 2018; 9:2263. [PMID: 30294320 PMCID: PMC6158324 DOI: 10.3389/fmicb.2018.02263] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 09/05/2018] [Indexed: 02/03/2023] Open
Abstract
Site-directed mutagenesis enables researchers to switch a gene of interest off for functional characterization of the gene. In the pathogenic yeasts, Cryptococcus neoformans and sister species C. deneoformans, this is almost exclusively achieved by introducing DNA into cells through either biolistic transformation or electroporation. The targeted gene is then disrupted by homologous recombination (HR) between the gene and the transforming DNA. Both techniques have downsides; biolistic transformation equipment is very expensive, limiting the use thereof to well-resourced laboratories, and HR occurs at extremely low frequencies in electroporated cryptococcal cells, making this method unappealing for gene targeting when not making use of additional modifications or methods to enhance HR in these cells. One approach to increase the frequency of HR in electroporated cryptococcal cells have recently been described. In this approach, CRISPR-Cas9 technology is utilized to form a double strand break in the targeted gene where after the occurrence of HR seems to be higher. The less expensive electroporation technique can therefore be used to deliver the CRISPR-Cas9 components into cells to disrupt a gene of interest, but only if the CRISPR components can be maintained for long enough in cells to enable their expression. Maintenance of episomal DNA occurs readily in C. deneoformans, but only under certain conditions in C. neoformans. In addition, CRISPR-Cas9 allows for gene complementation in order to fulfill Falkow’s molecular Koch’s postulates and adds other novel methods for studying genes as well, such as the addition of a fluorophore to an inactive Cas9 enzyme to highlight the location of a gene in a chromosome. These developments add less expensive alternatives to current methods, which could lead to more research on this yeast in developing countries where cryptococcal infections are more prevalent and researchers have access to more clinical isolates.
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Affiliation(s)
- Lukas M du Plooy
- Pathogenic Yeast Research Group, Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, Bloemfontein, South Africa
| | - Olihile M Sebolai
- Pathogenic Yeast Research Group, Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, Bloemfontein, South Africa
| | - Carolina H Pohl
- Pathogenic Yeast Research Group, Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, Bloemfontein, South Africa
| | - Jacobus Albertyn
- Pathogenic Yeast Research Group, Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, Bloemfontein, South Africa
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Fan Y, Lin X. Multiple Applications of a Transient CRISPR-Cas9 Coupled with Electroporation (TRACE) System in the Cryptococcus neoformans Species Complex. Genetics 2018; 208:1357-1372. [PMID: 29444806 PMCID: PMC5887135 DOI: 10.1534/genetics.117.300656] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 02/07/2018] [Indexed: 12/30/2022] Open
Abstract
Cryptococcus neoformans is a fungal pathogen that claims hundreds of thousands of lives annually. Targeted genetic manipulation through biolistic transformation in C. neoformans drove the investigation of this clinically important pathogen at the molecular level. Although costly and inefficient, biolistic transformation remains the major method for editing the Cryptococcus genome as foreign DNAs introduced by other methods such as electroporation are predominantly not integrated into the genome. Although the majority of DNAs introduced by biolistic transformation are stably inherited, the transformation efficiency and the homologous integration rate (∼1-10%) are low. Here, we developed a Transient CRISPR (clustered regularly interspaced short palindromic repeat)-Cas9 coupled with Electroporation (TRACE) system for targeted genetic manipulations in the C. neoformans species complex. This method took advantages of efficient genome integration due to double-strand breaks created at specific sites by the transient CRISPR-Cas9 system and the high transformation efficiency of electroporation. We demonstrated that TRACE can efficiently generate precise single-gene deletion mutants using the ADE2 locus as an example. This system can also effectively delete multiple genes in a single transformation, as evident by the successful generation of quadruple mfα1Δ2Δ3Δ4Δ mutants. In addition to generating gene deletion mutants, we complemented the ade2Δ mutant by integrating a wild-type ADE2 allele at the "safe haven" region (SH2) via homologous recombination using TRACE. Interestingly, introduced DNAs can be inserted at a designated genetic site without any homologous sequences, opening up numerous other applications. We expect that TRACE, an efficient, versatile, and cost-effective gene editing approach, will greatly accelerate research in this field.
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Affiliation(s)
- Yumeng Fan
- Department of Microbiology, University of Georgia, Athens, Georgia 30602
| | - Xiaorong Lin
- Department of Microbiology, University of Georgia, Athens, Georgia 30602
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Azevedo RVDM, Rizzo J, Rodrigues ML. Virulence Factors as Targets for Anticryptococcal Therapy. J Fungi (Basel) 2016; 2:jof2040029. [PMID: 29376946 PMCID: PMC5715936 DOI: 10.3390/jof2040029] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 11/18/2016] [Accepted: 11/25/2016] [Indexed: 12/24/2022] Open
Abstract
The global mortality due to cryptococcosis caused by Cryptococcus neoformans or C. gattii is unacceptably high. Currently available therapies are decades old and may be impacted by drug resistance. Therefore, the need for more effective antifungal drugs for cryptococcosis is evident. A number of Cryptococcus virulence factors have been studied in detail, providing crucial information about the fungal biology and putative molecular targets for antifungals. This review focuses on the use of well-described virulence factors of Cryptococcus as potential anticryptococcal agents.
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Affiliation(s)
- Renata V D M Azevedo
- Fundação Oswaldo Cruz-Fiocruz, Centro de Desenvolvimento Tecnológico em Saúde (CDTS), 21040-361 Rio de Janeiro, Brazil.
| | - Juliana Rizzo
- Instituto de Microbiologia Paulo de Góes (IMPG), Universidade Federal do Rio de Janeiro, 21941-902 Rio de Janeiro, Brazil.
- Instituto de Bioquímica Médica (IBqM), Universidade Federal do Rio de Janeiro, 21941-902 Rio de Janeiro, Brazil.
| | - Marcio L Rodrigues
- Fundação Oswaldo Cruz-Fiocruz, Centro de Desenvolvimento Tecnológico em Saúde (CDTS), 21040-361 Rio de Janeiro, Brazil.
- Instituto de Microbiologia Paulo de Góes (IMPG), Universidade Federal do Rio de Janeiro, 21941-902 Rio de Janeiro, Brazil.
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Design, Synthesis and Antifungal Activity of Novel Benzofuran-Triazole Hybrids. Molecules 2016; 21:molecules21060732. [PMID: 27338311 PMCID: PMC6274255 DOI: 10.3390/molecules21060732] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 05/27/2016] [Accepted: 06/01/2016] [Indexed: 11/24/2022] Open
Abstract
A series of novel benzofuran-triazole hybrids was designed and synthesized by click chemistry, and their structures were characterized by HRMS, FTIR and NMR. The in vitro antifungal activity of target compounds was evaluated using the microdilution broth method against five strains of pathogenic fungi. The result indicated that the target compounds exhibited moderate to satisfactory activity. Furthermore, molecular docking was performed to investigate the binding affinities and interaction modes between the target compound and N-myristoyltransferase. Based on the results, preliminary structure activity relationships (SARs) were summarized to serve as a foundation for further investigation.
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All about that fat: Lipid modification of proteins in Cryptococcus neoformans. J Microbiol 2016; 54:212-22. [PMID: 26920881 DOI: 10.1007/s12275-016-5626-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 02/01/2016] [Accepted: 02/01/2016] [Indexed: 12/17/2022]
Abstract
Lipid modification of proteins is a widespread, essential process whereby fatty acids, cholesterol, isoprenoids, phospholipids, or glycosylphospholipids are attached to polypeptides. These hydrophobic groups may affect protein structure, function, localization, and/or stability; as a consequence such modifications play critical regulatory roles in cellular systems. Recent advances in chemical biology and proteomics have allowed the profiling of modified proteins, enabling dissection of the functional consequences of lipid addition. The enzymes that mediate lipid modification are specific for both the lipid and protein substrates, and are conserved from fungi to humans. In this article we review these enzymes, their substrates, and the processes involved in eukaryotic lipid modification of proteins. We further focus on its occurrence in the fungal pathogen Cryptococcus neoformans, highlighting unique features that are both relevant for the biology of the organism and potentially important in the search for new therapies.
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Abstract
Enzymes play key roles in fungal pathogenesis. Manipulation of enzyme expression or activity can significantly alter the infection process, and enzyme expression profiles can be a hallmark of disease. Hence, enzymes are worthy targets for better understanding pathogenesis and identifying new options for combatting fungal infections. Advances in genomics, proteomics, transcriptomics, and mass spectrometry have enabled the identification and characterization of new fungal enzymes. This review focuses on recent developments in the virulence-associated enzymes from Cryptococcus neoformans. The enzymatic suite of C. neoformans has evolved for environmental survival, but several of these enzymes play a dual role in colonizing the mammalian host. We also discuss new therapeutic and diagnostic strategies that could be based on the underlying enzymology.
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Rampoldi F, Bonrouhi M, Boehm ME, Lehmann WD, Popovic ZV, Kaden S, Federico G, Brunk F, Gröne HJ, Porubsky S. Immunosuppression and Aberrant T Cell Development in the Absence of N-Myristoylation. THE JOURNAL OF IMMUNOLOGY 2015; 195:4228-43. [DOI: 10.4049/jimmunol.1500622] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 09/01/2015] [Indexed: 01/01/2023]
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17
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Fang W, Robinson DA, Raimi OG, Blair DE, Harrison JR, Lockhart DEA, Torrie LS, Ruda GF, Wyatt PG, Gilbert IH, van Aalten DMF. N-myristoyltransferase is a cell wall target in Aspergillus fumigatus. ACS Chem Biol 2015; 10:1425-34. [PMID: 25706802 PMCID: PMC4477619 DOI: 10.1021/cb5008647] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Treatment of filamentous fungal infections relies on a limited repertoire of antifungal agents. Compounds possessing novel modes of action are urgently required. N-myristoylation is a ubiquitous modification of eukaryotic proteins. The enzyme N-myristoyltransferase (NMT) has been considered a potential therapeutic target in protozoa and yeasts. Here, we show that the filamentous fungal pathogen Aspergillus fumigatus possesses an active NMT enzyme that is essential for survival. Surprisingly, partial repression of the gene revealed downstream effects of N-myristoylation on cell wall morphology. Screening a library of inhibitors led to the discovery of a pyrazole sulphonamide compound that inhibits the enzyme and is fungicidal under partially repressive nmt conditions. Together with a crystallographic complex showing the inhibitor binding in the peptide substrate pocket, we provide evidence of NMT being a potential drug target in A. fumigatus.
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Affiliation(s)
- Wenxia Fang
- Division of Molecular Microbiology, ‡Division of Biological
Chemistry and Drug Discovery, §MRC Protein Phosphorylation and Ubiquitylation
Unit, College of Life Sciences, University of Dundee, Dundee, DD1 5EH, United Kingdom
| | - David A. Robinson
- Division of Molecular Microbiology, ‡Division of Biological
Chemistry and Drug Discovery, §MRC Protein Phosphorylation and Ubiquitylation
Unit, College of Life Sciences, University of Dundee, Dundee, DD1 5EH, United Kingdom
| | - Olawale G. Raimi
- Division of Molecular Microbiology, ‡Division of Biological
Chemistry and Drug Discovery, §MRC Protein Phosphorylation and Ubiquitylation
Unit, College of Life Sciences, University of Dundee, Dundee, DD1 5EH, United Kingdom
| | - David E. Blair
- Division of Molecular Microbiology, ‡Division of Biological
Chemistry and Drug Discovery, §MRC Protein Phosphorylation and Ubiquitylation
Unit, College of Life Sciences, University of Dundee, Dundee, DD1 5EH, United Kingdom
| | - Justin R. Harrison
- Division of Molecular Microbiology, ‡Division of Biological
Chemistry and Drug Discovery, §MRC Protein Phosphorylation and Ubiquitylation
Unit, College of Life Sciences, University of Dundee, Dundee, DD1 5EH, United Kingdom
| | - Deborah E. A. Lockhart
- Division of Molecular Microbiology, ‡Division of Biological
Chemistry and Drug Discovery, §MRC Protein Phosphorylation and Ubiquitylation
Unit, College of Life Sciences, University of Dundee, Dundee, DD1 5EH, United Kingdom
| | - Leah S. Torrie
- Division of Molecular Microbiology, ‡Division of Biological
Chemistry and Drug Discovery, §MRC Protein Phosphorylation and Ubiquitylation
Unit, College of Life Sciences, University of Dundee, Dundee, DD1 5EH, United Kingdom
| | - Gian Filippo Ruda
- Division of Molecular Microbiology, ‡Division of Biological
Chemistry and Drug Discovery, §MRC Protein Phosphorylation and Ubiquitylation
Unit, College of Life Sciences, University of Dundee, Dundee, DD1 5EH, United Kingdom
| | - Paul G. Wyatt
- Division of Molecular Microbiology, ‡Division of Biological
Chemistry and Drug Discovery, §MRC Protein Phosphorylation and Ubiquitylation
Unit, College of Life Sciences, University of Dundee, Dundee, DD1 5EH, United Kingdom
| | - Ian H. Gilbert
- Division of Molecular Microbiology, ‡Division of Biological
Chemistry and Drug Discovery, §MRC Protein Phosphorylation and Ubiquitylation
Unit, College of Life Sciences, University of Dundee, Dundee, DD1 5EH, United Kingdom
| | - Daan M. F. van Aalten
- Division of Molecular Microbiology, ‡Division of Biological
Chemistry and Drug Discovery, §MRC Protein Phosphorylation and Ubiquitylation
Unit, College of Life Sciences, University of Dundee, Dundee, DD1 5EH, United Kingdom
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18
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Zhang N, Park YD, Williamson PR. New technology and resources for cryptococcal research. Fungal Genet Biol 2015; 78:99-107. [PMID: 25460849 PMCID: PMC4433448 DOI: 10.1016/j.fgb.2014.11.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Revised: 11/02/2014] [Accepted: 11/06/2014] [Indexed: 11/26/2022]
Abstract
Rapid advances in molecular biology and genome sequencing have enabled the generation of new technology and resources for cryptococcal research. RNAi-mediated specific gene knock down has become routine and more efficient by utilizing modified shRNA plasmids and convergent promoter RNAi constructs. This system was recently applied in a high-throughput screen to identify genes involved in host-pathogen interactions. Gene deletion efficiencies have also been improved by increasing rates of homologous recombination through a number of approaches, including a combination of double-joint PCR with split-marker transformation, the use of dominant selectable markers and the introduction of Cre-Loxp systems into Cryptococcus. Moreover, visualization of cryptococcal proteins has become more facile using fusions with codon-optimized fluorescent tags, such as green or red fluorescent proteins or, mCherry. Using recent genome-wide analytical tools, new transcriptional factors and regulatory proteins have been identified in novel virulence-related signaling pathways by employing microarray analysis, RNA-sequencing and proteomic analysis.
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Affiliation(s)
- Nannan Zhang
- Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institution of Health, Bethesda, MD, United States
| | - Yoon-Dong Park
- Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institution of Health, Bethesda, MD, United States
| | - Peter R Williamson
- Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institution of Health, Bethesda, MD, United States.
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19
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Lin X, Chacko N, Wang L, Pavuluri Y. Generation of stable mutants and targeted gene deletion strains in Cryptococcus neoformans through electroporation. Med Mycol 2014; 53:225-34. [PMID: 25541555 DOI: 10.1093/mmy/myu083] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Cryptococcus neoformans is the etiologic agent of cryptococcal meningitis that causes more than half a million deaths worldwide each year. This capsulated basidiomycetous yeast also serves as a model for micropathogenic studies. The ability to make stable mutants, either via ectopic integration or homologous recombination, has been accomplished using biolistic transformation. This technical advance has greatly facilitated the research on the basic biology and pathogenic mechanisms of this pathogen in the past two decades. However, biolistic transformation is costly, and its reproducibility varies widely. Here we found that stable ectopic integration or targeted gene deletion via homologous replacement could be accomplished through electroporative transformation. The stability of the transformants obtained through electroporation and the frequency of homologous replacement is highly dependent on the selective marker. A frequency of homologous recombination among the stable transformants obtained by electroporation is comparable to those obtained by biolistic transformation (∼10%) when dominant drug selection markers are used, which is much higher than what has been previously reported for electroporation when auxotrophic markers were used (0.001% to 0.1%). Furthermore, disruption of the KU80 gene or generation of gene deletion constructs using the split marker strategy, two approaches known to increase homologous replacement among transformants obtained through biolistic transformation, also increase the frequency of homologous replacement among transformants obtained through electroporation. Therefore, electroporation provides a low cost alternative for mutagenesis in Cryptococcus.
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Affiliation(s)
- Xiaorong Lin
- Department of Biology, Texas A&M University, College Station, Texas, USA
| | - Nadia Chacko
- Department of Biology, Texas A&M University, College Station, Texas, USA
| | - Linqi Wang
- Department of Biology, Texas A&M University, College Station, Texas, USA
| | - Yashwant Pavuluri
- Department of Biology, Texas A&M University, College Station, Texas, USA
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20
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Olaleye TO, Brannigan JA, Roberts SM, Leatherbarrow RJ, Wilkinson AJ, Tate EW. Peptidomimetic inhibitors of N-myristoyltransferase from human malaria and leishmaniasis parasites. Org Biomol Chem 2014; 12:8132-7. [PMID: 25230674 PMCID: PMC4224572 DOI: 10.1039/c4ob01669f] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Peptidomimetic inhibitors of N-myristoyltransferase from malaria and leishmaniasis parasites have been designed with nanomolar potency, and reveal the first direct structural evidence for a ternary NMT/CoA/myristoyl peptide product complex.
N-Myristoyltransferase (NMT) has been shown to be essential in Leishmania and subsequently validated as a drug target in Plasmodium. Herein, we discuss the use of antifungal NMT inhibitors as a basis for inhibitor development resulting in the first sub-micromolar peptidomimetic inhibitors of Plasmodium and Leishmania NMTs. High-resolution structures of these inhibitors with Plasmodium and Leishmania NMTs permit a comparative analysis of binding modes, and provide the first crystal structure evidence for a ternary NMT-Coenzyme A/myristoylated peptide product complex.
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Affiliation(s)
- Tayo O Olaleye
- Department of Chemistry, Imperial College London, London, SW7 2AZ, UK.
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21
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A target repurposing approach identifies N-myristoyltransferase as a new candidate drug target in filarial nematodes. PLoS Negl Trop Dis 2014; 8:e3145. [PMID: 25188325 PMCID: PMC4154664 DOI: 10.1371/journal.pntd.0003145] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Accepted: 07/25/2014] [Indexed: 11/19/2022] Open
Abstract
Myristoylation is a lipid modification involving the addition of a 14-carbon unsaturated fatty acid, myristic acid, to the N-terminal glycine of a subset of proteins, a modification that promotes their binding to cell membranes for varied biological functions. The process is catalyzed by myristoyl-CoA:protein N-myristoyltransferase (NMT), an enzyme which has been validated as a drug target in human cancers, and for infectious diseases caused by fungi, viruses and protozoan parasites. We purified Caenorhabditis elegans and Brugia malayi NMTs as active recombinant proteins and carried out kinetic analyses with their essential fatty acid donor, myristoyl-CoA and peptide substrates. Biochemical and structural analyses both revealed that the nematode enzymes are canonical NMTs, sharing a high degree of conservation with protozoan NMT enzymes. Inhibitory compounds that target NMT in protozoan species inhibited the nematode NMTs with IC50 values of 2.5–10 nM, and were active against B. malayi microfilariae and adult worms at 12.5 µM and 50 µM respectively, and C. elegans (25 µM) in culture. RNA interference and gene deletion in C. elegans further showed that NMT is essential for nematode viability. The effects observed are likely due to disruption of the function of several downstream target proteins. Potential substrates of NMT in B. malayi are predicted using bioinformatic analysis. Our genetic and chemical studies highlight the importance of myristoylation in the synthesis of functional proteins in nematodes and have shown for the first time that NMT is required for viability in parasitic nematodes. These results suggest that targeting NMT could be a valid approach for the development of chemotherapeutic agents against nematode diseases including filariasis. Lymphatic filariasis and onchocerciasis are neglected tropical diseases caused by filarial nematodes. The limitations of existing drugs to treat these infections highlight the need for new drugs. In the present study, we investigated myristoylation, a lipid modification of a subset of proteins that promotes their binding to cell membranes for varied biological functions. The process is catalyzed by N-myristoyltransferase (NMT), an enzyme which has been validated as a drug target in protozoan parasites. We performed kinetic analyses on Caenorhabditis elegans and Brugia malayi NMTs. NMT inhibitors were active against B. malayi microfilariae and adult worms, and C. elegans in culture. RNA interference and gene deletion in C. elegans further demonstrated that NMT is essential for nematode viability. Our genetic and chemical studies indicate the importance of myristoylation in the synthesis of functional proteins in nematodes and have shown for the first time that NMT is required for viability in parasitic nematodes. These results suggest that targeting NMT could be a valid approach for the development of new therapies against nematode infection including filarial diseases.
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22
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Recent Advances in The Discovery ofN-Myristoyltransferase Inhibitors. ChemMedChem 2014; 9:2425-37. [DOI: 10.1002/cmdc.201402174] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Revised: 07/17/2014] [Indexed: 01/08/2023]
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23
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Kwon-Chung KJ, Fraser JA, Doering TL, Wang Z, Janbon G, Idnurm A, Bahn YS. Cryptococcus neoformans and Cryptococcus gattii, the etiologic agents of cryptococcosis. Cold Spring Harb Perspect Med 2014; 4:a019760. [PMID: 24985132 PMCID: PMC4066639 DOI: 10.1101/cshperspect.a019760] [Citation(s) in RCA: 294] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Cryptococcus neoformans and Cryptococcus gattii are the two etiologic agents of cryptococcosis. They belong to the phylum Basidiomycota and can be readily distinguished from other pathogenic yeasts such as Candida by the presence of a polysaccharide capsule, formation of melanin, and urease activity, which all function as virulence determinants. Infection proceeds via inhalation and subsequent dissemination to the central nervous system to cause meningoencephalitis. The most common risk for cryptococcosis caused by C. neoformans is AIDS, whereas infections caused by C. gattii are more often reported in immunocompetent patients with undefined risk than in the immunocompromised. There have been many chapters, reviews, and books written on C. neoformans. The topics we focus on in this article include species description, pathogenesis, life cycle, capsule, and stress response, which serve to highlight the specializations in virulence that have occurred in this unique encapsulated melanin-forming yeast that causes global deaths estimated at more than 600,000 annually.
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Affiliation(s)
- Kyung J Kwon-Chung
- Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892
| | - James A Fraser
- Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Tamara L Doering
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Zhou Wang
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Guilhem Janbon
- Unité Biologie et Pathogénicité Fongiques, Institut Pasteur, 75015 Paris, France
| | - Alexander Idnurm
- Division of Cell Biology and Biophysics, School of Biological Sciences, University of Missouri, Kansas City, Missouri 64110
| | - Yong-Sun Bahn
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Republic of Korea
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24
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Roberts A, Torrie L, Wyllie S, Fairlamb A. Biochemical and genetic characterization of Trypanosoma cruzi N-myristoyltransferase. Biochem J 2014; 459:323-32. [PMID: 24444291 PMCID: PMC3969225 DOI: 10.1042/bj20131033] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 01/20/2014] [Accepted: 01/21/2014] [Indexed: 12/20/2022]
Abstract
Co- and post-translational N-myristoylation is known to play a role in the correct subcellular localization of specific proteins in eukaryotes. The enzyme that catalyses this reaction, NMT (N-myristoyltransferase), has been pharmacologically validated as a drug target in the African trypanosome, Trypanosoma brucei. In the present study, we evaluate NMT as a potential drug target in Trypanosoma cruzi, the causative agent of Chagas' disease, using chemical and genetic approaches. Replacement of both allelic copies of TcNMT (T. cruzi NMT) was only possible in the presence of a constitutively expressed ectopic copy of the gene, indicating that this gene is essential for survival of T. cruzi epimastigotes. The pyrazole sulphonamide NMT inhibitor DDD85646 is 13-23-fold less potent against recombinant TcNMT than TbNMT (T. brucei NMT), with Ki values of 12.7 and 22.8 nM respectively, by scintillation proximity or coupled assay methods. DDD85646 also inhibits growth of T. cruzi epimastigotes (EC50=6.9 μM), but is ~1000-fold less potent than that reported for T. brucei. On-target activity is demonstrated by shifts in cell potency in lines that over- and under-express NMT and by inhibition of intracellular N-myristoylation of several proteins in a dose-dependent manner. Collectively, our findings suggest that N-myristoylation is an essential and druggable target in T. cruzi.
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Key Words
- chagas’ disease
- click chemistry
- drug target
- n-myristoylation
- trypanosoma cruzi
- validation
- cap5.5, cytoskeleton-associated protein 5.5
- dig, digoxigenin
- dko, double knockout
- dmem, dulbecco’s modified eagle’s medium
- hyg, hygromycin phosphotransferase
- nmt, n-myristoyltransferase
- nmtoe, nmt overexpressor
- pac, puromycin n-acetyltransferase
- rth/fbs, rpmi 1640 medium supplemented with trypticase, haemin, hepes and 10% heat-inactivated fbs
- sko, single knockout
- tbnmt, trypanosoma brucei nmt
- tcep, tris-(2-carboxyethyl)phosphine
- tcnmt, trypanosoma cruzi nmt
- tctryr, trypanosoma cruzi trypanothione reductase
- wt, wild-type
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Affiliation(s)
- Adam J. Roberts
- *Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dundee DD1 5EH, U.K
| | - Leah S. Torrie
- *Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dundee DD1 5EH, U.K
| | - Susan Wyllie
- *Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dundee DD1 5EH, U.K
| | - Alan H. Fairlamb
- *Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dundee DD1 5EH, U.K
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25
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Ryu CK, Nho JH, Jin G, Oh SY, Choi SJ. Synthesis of Benzofuro[6,7- d]thiazoles, Benzofuro[7,6- d]thiazoles and 6-Arylaminobenzo[ d]thiazole-4,7-diones as Antifungal Agent. Chem Pharm Bull (Tokyo) 2014; 62:668-74. [DOI: 10.1248/cpb.c14-00146] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Chung-Kyu Ryu
- College of Pharmacy & Graduate School of Pharmaceutical Sciences, Ewha Womans University
| | - Ji-Hee Nho
- College of Pharmacy & Graduate School of Pharmaceutical Sciences, Ewha Womans University
| | - Guohua Jin
- College of Pharmacy & Graduate School of Pharmaceutical Sciences, Ewha Womans University
| | - Sun Young Oh
- College of Pharmacy & Graduate School of Pharmaceutical Sciences, Ewha Womans University
| | - Soo Jung Choi
- College of Pharmacy & Graduate School of Pharmaceutical Sciences, Ewha Womans University
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26
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Traverso JA, Giglione C, Meinnel T. High-throughput profiling of N-myristoylation substrate specificity across species including pathogens. Proteomics 2013; 13:25-36. [PMID: 23165749 DOI: 10.1002/pmic.201200375] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Revised: 10/08/2012] [Accepted: 10/09/2012] [Indexed: 11/10/2022]
Abstract
One of the most critical modifications affecting the N-terminus of proteins is N-myristoylation. This irreversible modification affects the membrane-binding properties of crucial proteins involved in signal transduction cascades. This cotranslational modification, catalyzed by N-myristoyl transferase, occurs both in lower and higher eukaryotes and is a validated therapeutic target for several pathologies. However, this lipidation proves very difficult to be evidenced in vivo even with state-of-the-art proteomics approaches or bioinformatics tools. A large part of N-myristoylated proteins remains to be discovered and the rules of substrate specificity need to be established in each organism. Because the peptide substrate recognition occurs around the first eight residues, short peptides are used for modeling the reaction in vitro. Here, we provide a novel approach including a dedicated peptide array for high-throughput profiling protein N-myristoylation specificity. We show that myristoylation predictive tools need to be fine-tuned to organisms and that their poor accuracy should be significantly enhanced. This should lead to strongly improved knowledge of the number and function of myristoylated proteins occurring in any proteome.
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Affiliation(s)
- José A Traverso
- CNRS, Centre de Recherche de Gif, Institut des Sciences du Végétal, Gif-sur-Yvette, France
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27
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Yu Z, Brannigan JA, Moss DK, Brzozowski AM, Wilkinson AJ, Holder AA, Tate EW, Leatherbarrow RJ. Design and synthesis of inhibitors of Plasmodium falciparum N-myristoyltransferase, a promising target for antimalarial drug discovery. J Med Chem 2012; 55:8879-90. [PMID: 23035716 DOI: 10.1021/jm301160h] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Design of inhibitors for N-myristoyltransferase (NMT), an enzyme responsible for protein trafficking in Plasmodium falciparum , the most lethal species of parasites that cause malaria, is described. Chemistry-driven optimization of compound 1 from a focused NMT inhibitor library led to the identification of two early lead compounds 4 and 25, which showed good enzyme and cellular potency and excellent selectivity over human NMT. These molecules provide a valuable starting point for further development.
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Affiliation(s)
- Zhiyong Yu
- Department of Chemistry, Imperial College London, London SW7 2AZ, UK
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28
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Ryu CK, Kim YH, Im HA, Kim JY, Yoon JH, Kim A. Synthesis and antifungal activity of 6,7-bis(arylthio)-quinazoline-5,8-diones and furo[2,3-f]quinazolin-5-ols. Bioorg Med Chem Lett 2012; 22:500-3. [DOI: 10.1016/j.bmcl.2011.10.099] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Revised: 10/18/2011] [Accepted: 10/27/2011] [Indexed: 10/15/2022]
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29
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Taha MO, Qandil AM, Al-Haraznah T, Khalaf RA, Zalloum H, Al-Bakri AG. Discovery of New Antifungal Leads via Pharmacophore Modeling and QSAR Analysis of Fungal N-Myristoyl Transferase Inhibitors Followed by In Silico Screening. Chem Biol Drug Des 2011; 78:391-407. [DOI: 10.1111/j.1747-0285.2011.01160.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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30
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N-myristoyltransferase in the leukocytic development processes. Cell Tissue Res 2011; 345:203-11. [PMID: 21698528 DOI: 10.1007/s00441-011-1202-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2011] [Accepted: 06/03/2011] [Indexed: 02/07/2023]
Abstract
The lipidic modification of proteins has recently been shown to be of immense importance, although many of the roles of these modifications remain as yet unidentified. One of such key modifications occurring on several proteins is the covalent addition of a 14-carbon long saturated fatty acid, a process termed myristoylation. Myristoylation can occur during both co-translational protein synthesis and posttranslationally, confers lipophilicity to protein molecules, and controls protein functions. The protein myristoylation process is catalyzed by the enzyme N-myristoyltransferase (NMT), which exists as two isoforms: NMT1 and NMT2. NMT1 is essential for growth and development, during which rapid cellular proliferation is required, in a variety of organisms. NMT1 is also reported to be elevated in many cancerous states, which also involve rapid cellular growth, albeit in an unwanted and uncontrolled manner. The delineation of myristoylation-dependent cellular functions is still in a state of infancy, and many of the roles of the myristoylated proteins remain to be established. The development of cells of the leukocytic lineage represents a phase of rapid growth and development, and we have observed that NMT1 plays a role in this process. The current review outlines the roles of NMT1 in the growth and differentiation of the cells of leukocytic origin. The described studies clearly demonstrate the roles of NMT1 in the regulation of the developmental processes of the leukocytes cells and provide a basis for further research with the aim of unraveling the roles of protein myristoylation in both cellular and physiological context.
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31
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Barnett JA. A history of research on yeasts 14: medical yeasts part 2, Cryptococcus neoformans. Yeast 2011; 27:875-904. [PMID: 20641025 DOI: 10.1002/yea.1786] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Affiliation(s)
- James A Barnett
- School of Biological Sciences, University of East Anglia, Norwich, UK.
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32
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Ryu CK, Kim YH, Nho JH, Hong JA, Yoon JH, Kim A. Synthesis and antifungal activity of furo[2,3-f]quinolin-5-ols. Bioorg Med Chem Lett 2010; 21:952-5. [PMID: 21215618 DOI: 10.1016/j.bmcl.2010.12.058] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2010] [Revised: 11/25/2010] [Accepted: 12/09/2010] [Indexed: 11/17/2022]
Abstract
Furo[2,3-f]quinolin-5-ol derivatives were synthesized and tested for in vitro antifungal activity against Candida,Aspergillus species, and Cryptococcus neoformans. Among them tested, many furo[2,3-f]quinolin-5-ols showed good antifungal activity. The results suggest that furo[2,3-f]quinolin-5-ols would be promising antifungal agents.
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Affiliation(s)
- Chung-Kyu Ryu
- College of Pharmacy, Ewha Womans University, Seoul, Republic of Korea.
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33
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Ryu CK, Song AL, Lee JY, Hong JA, Yoon JH, Kim A. Synthesis and antifungal activity of benzofuran-5-ols. Bioorg Med Chem Lett 2010; 20:6777-80. [PMID: 20851600 DOI: 10.1016/j.bmcl.2010.08.129] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2010] [Revised: 08/18/2010] [Accepted: 08/27/2010] [Indexed: 10/19/2022]
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34
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Tautz L, Rétey J. A highly convergent synthesis of myristoyl-carba(dethia)-coenzyme A. European J Org Chem 2010; 2010:1728-1735. [PMID: 22347809 DOI: 10.1002/ejoc.200901410] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Co-translational myristoylation of the N-terminal glycine residue of diverse signaling proteins is required for membrane attachment and proper function of these molecules. The transfer of myristate from myristoyl-coenzyme A (myr-CoA) is catalyzed by the enzyme N-myristoyltransferase (Nmt). Nmt has been implicated in a number of human diseases, including cancer and epilepsy, as well as pathogenic mechanisms such as fungal and virus infections, including HIV and Hepatitis B. Rational design has led to the development of potent competitive inhibitors, including several non-hydrolysable acyl-CoA substrate analogues. However, linear synthetic strategies, following the route of the original CoA synthesis, generate such analogues in very low over all yields that typically are not sufficient for in vivo studies. Here, we present a new, highly convergent synthesis of myristoyl-carba(dethia)-coenzyme A 1 that allows to obtain this substrate analogue in 11-fold increased yield compared to the reported linear synthesis. In addition, enzymatic cleavage of the adenosine-2',3'-cyclophosphate in the last step of the synthesis proved to be an efficient way to obtain the isomerically pure 3'-phosphate 1.
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Wright MH, Heal WP, Mann DJ, Tate EW. Protein myristoylation in health and disease. J Chem Biol 2010; 3:19-35. [PMID: 19898886 PMCID: PMC2816741 DOI: 10.1007/s12154-009-0032-8] [Citation(s) in RCA: 181] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2009] [Revised: 10/05/2009] [Accepted: 10/19/2009] [Indexed: 02/07/2023] Open
Abstract
N-myristoylation is the attachment of a 14-carbon fatty acid, myristate, onto the N-terminal glycine residue of target proteins, catalysed by N-myristoyltransferase (NMT), a ubiquitous and essential enzyme in eukaryotes. Many of the target proteins of NMT are crucial components of signalling pathways, and myristoylation typically promotes membrane binding that is essential for proper protein localisation or biological function. NMT is a validated therapeutic target in opportunistic infections of humans by fungi or parasitic protozoa. Additionally, NMT is implicated in carcinogenesis, particularly colon cancer, where there is evidence for its upregulation in the early stages of tumour formation. However, the study of myristoylation in all organisms has until recently been hindered by a lack of techniques for detection and identification of myristoylated proteins. Here we introduce the chemistry and biology of N-myristoylation and NMT, and discuss new developments in chemical proteomic technologies that are meeting the challenge of studying this important co-translational modification in living systems.
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Affiliation(s)
- Megan H. Wright
- Chemical Biology Centre, Imperial College London, Exhibition Rd., London, SW72AZ UK
- Department of Chemistry, Imperial College London, Exhibition Rd., London, SW72AZ UK
- Department of Life Sciences, Imperial College London, Exhibition Rd., London, SW72AZ UK
| | - William P. Heal
- Department of Chemistry, Imperial College London, Exhibition Rd., London, SW72AZ UK
- Department of Life Sciences, Imperial College London, Exhibition Rd., London, SW72AZ UK
| | - David J. Mann
- Chemical Biology Centre, Imperial College London, Exhibition Rd., London, SW72AZ UK
- Department of Life Sciences, Imperial College London, Exhibition Rd., London, SW72AZ UK
| | - Edward W. Tate
- Chemical Biology Centre, Imperial College London, Exhibition Rd., London, SW72AZ UK
- Department of Chemistry, Imperial College London, Exhibition Rd., London, SW72AZ UK
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Price HP, Güther MLS, Ferguson MAJ, Smith DF. Myristoyl-CoA:protein N-myristoyltransferase depletion in trypanosomes causes avirulence and endocytic defects. Mol Biochem Parasitol 2009; 169:55-8. [PMID: 19782106 PMCID: PMC2789243 DOI: 10.1016/j.molbiopara.2009.09.006] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2009] [Revised: 09/14/2009] [Accepted: 09/17/2009] [Indexed: 12/17/2022]
Abstract
The enzyme myristoyl-CoA:protein N-myristoyltransferase (NMT) catalyses the co-translational covalent attachment of the fatty acid myristate to the N-terminus of target proteins. NMT is known to be essential for viability in Trypanosoma brucei and Leishmania major. Here we describe phenotypic analysis of T. brucei bloodstream form cells following knockdown of NMT expression by tetracycline-inducible RNA interference. Cell death occurs from 72 h post-induction, with approximately 50% of cells displaying a defect in endocytic uptake by this time. The majority of these induced cells do not have an enlarged flagellar pocket typical of a block in endocytosis but vesicle accumulation around the flagellar pocket indicates a defect in vesicular progression following endocytic fusion. Induced parasites have a wild-type or slightly enlarged Golgi apparatus, unlike the phenotype of cells with reduced expression of a major N-myristoylated protein, ARL1. Critically we show that following NMT knockdown, T. brucei bloodstream form cells are unable to establish an infection in a mouse model, therefore providing further validation of this enzyme as a target for drug development.
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Affiliation(s)
- Helen P Price
- Centre for Immunology and Infection, Department of Biology, University of York, UK.
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Sheng C, Ji H, Miao Z, Che X, Yao J, Wang W, Dong G, Guo W, Lü J, Zhang W. Homology modeling and molecular dynamics simulation of N-myristoyltransferase from protozoan parasites: active site characterization and insights into rational inhibitor design. J Comput Aided Mol Des 2009; 23:375-89. [PMID: 19370313 DOI: 10.1007/s10822-009-9267-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2008] [Accepted: 03/26/2009] [Indexed: 11/25/2022]
Abstract
Myristoyl-CoA:protein N-myristoyltransferase (NMT) is a cytosolic monomeric enzyme that catalyzes the transfer of the myristoyl group from myristoyl-CoA to the N-terminal glycine of a number of eukaryotic cellular and viral proteins. Recent experimental data suggest NMT from parasites could be a promising new target for the design of novel antiparasitic agents with new mode of action. However, the active site topology and inhibitor specificity of these enzymes remain unclear. In this study, three-dimensional models of NMT from Plasmodium falciparum (PfNMT), Leishmania major (LmNMT) and Trypanosoma brucei (TbNMT) were constructed on the basis of the crystal structures of fungal NMTs using homology modeling method. The models were further refined by energy minimization and molecular dynamics simulations. The active sites of PfNMT, LmNMT and TbNMT were characterized by multiple copy simultaneous search (MCSS). MCSS functional maps reveal that PfNMT, LmNMT and TbNMT share a similar active site topology, which is defined by two hydrophobic pockets, a hydrogen-bonding (HB) pocket, a negatively-charged HB pocket and a positively-charged HB pocket. Flexible docking approaches were then employed to dock known inhibitors into the active site of PfNMT. The binding mode, structure-activity relationships and selectivity of inhibitors were investigated in detail. From the results of molecular modeling, the active site architecture and certain key residues responsible for inhibitor binding were identified, which provided insights for the design of novel inhibitors of parasitic NMTs.
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Affiliation(s)
- Chunquan Sheng
- School of Pharmacy, Military Key Laboratory of Medicinal Chemistry, Second Military Medical University, Shanghai, People's Republic of China
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38
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Ruff JA, Lodge JK, Baker LG. Three galactose inducible promoters for use in C. neoformans var. grubii. Fungal Genet Biol 2008; 46:9-16. [PMID: 18952189 DOI: 10.1016/j.fgb.2008.10.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2008] [Revised: 10/07/2008] [Accepted: 10/07/2008] [Indexed: 10/21/2022]
Abstract
Cryptococcus neoformans is the causative agent of cryptococcal meningoencephalitis, most frequently occurring in immunocompromised individuals. There are three varieties of C. neoformans, var. grubii, var. neoformans, and var. gatti. Worldwide var. grubii is the most prevalent clinical isolate. However, few tools for the study of essential genes in var. grubii exist. Here we describe three endogenous inducible promoters for use in the study of this important opportunistic pathogen. We identified eight potential homologs of S. cerevisiae galactose genes in var. grubii. We found that GAL1, GAL7, and UGE2 were regulated by glucose and galactose and can be used successfully during mating. Our analysis indicated these promoters should prove to be excellent tools for analysis of genes in var. grubii.
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Affiliation(s)
- Jack A Ruff
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, 1100 S. Grand Boulevard, Saint Louis, MO 63104, USA
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Islam NN, Igarashi K, Tachibana T, Ooshima H, Azuma M. Synthesis and degradation of acyl peptide using enzyme from Pseudomonas aeruginosa. J Biosci Bioeng 2008; 105:282-7. [PMID: 18397780 DOI: 10.1263/jbb.105.282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2007] [Accepted: 12/22/2007] [Indexed: 11/17/2022]
Abstract
The detailed properties of the enzyme from Pseudomonas aeruginosa, which catalyzes the N-acyl linkage between myristic acid and the N-terminal glycine residue of the octapeptide GNAAAARR-NH(2) (PKA) in aqueous solution without ATP and CoA, were studied. The substrate specificity for the acyl peptide in the synthetic reaction was examined, and it was found that at least eight amino acid residues are required for the reaction and that the N-terminal glycine residue is not absolutely essential for the reaction because the activity was detected using the octapeptide that has an N-terminal alanine. The activity was also strongly affected by the amino acid sequence because the activity was very weak in the reaction using GARASVLS-NH(2) (HIV-1p17(gag)). The substrate specificity for fatty acids was also examined. In the reactions using lauric acid and decanoic acid, only slight activities were detected; however, those activities were very small compared with the activity in the reaction using myristic acid. In addition, the degradation of myristoyl PKA by the enzyme was detected, although there are only a few reports on demyristoylation. The optimum pH and temperature of the degradation reaction were consistent with those of the synthetic reaction. The degradation reaction was inhibited by divalent cations.
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Affiliation(s)
- Nazneen Naher Islam
- Department of Applied Chemistry and Bioengineering, Graduate School of Engineering, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan
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40
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Bowyer P, Gunaratne R, Grainger M, Withers-Martinez C, Wickramsinghe S, Tate E, Leatherbarrow R, Brown K, Holder A, Smith D. Molecules incorporating a benzothiazole core scaffold inhibit the N-myristoyltransferase of Plasmodium falciparum. Biochem J 2007; 408:173-80. [PMID: 17714074 PMCID: PMC2267354 DOI: 10.1042/bj20070692] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Recombinant N-myristoyltransferase of Plasmodium falciparum (termed PfNMT) has been used in the development of a SPA (scintillation proximity assay) suitable for automation and high-throughput screening of inhibitors against this enzyme. The ability to use the SPA has been facilitated by development of an expression and purification system which yields considerably improved quantities of soluble active recombinant PfNMT compared with previous studies. Specifically, yields of pure protein have been increased from 12 microg x l(-1) to >400 microg x l(-1) by use of a synthetic gene with codon usage optimized for expression in an Escherichia coli host. Preliminary small-scale 'piggyback' inhibitor studies using the SPA have identified a family of related molecules containing a core benzothiazole scaffold with IC50 values <50 microM, which demonstrate selectivity over human NMT1. Two of these compounds, when tested against cultured parasites in vitro, reduced parasitaemia by >80% at a concentration of 10 microM.
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Affiliation(s)
- Paul W. Bowyer
- *Wellcome Trust Laboratories for Molecular Parasitology, Imperial College London, London SW7 2AZ, U.K
- †Division of Cell and Molecular Biology, Centre for Molecular Microbiology and Infection, Imperial College London, London SW7 2AZ, U.K
- ‡Department of Chemistry, Imperial College London, London SW7 2AZ, U.K
| | - Ruwani S. Gunaratne
- §Division of Parasitology, MRC National Institute for Medical Research, Mill Hill, London NW7 1AA, U.K
| | - Munira Grainger
- §Division of Parasitology, MRC National Institute for Medical Research, Mill Hill, London NW7 1AA, U.K
| | | | | | - Edward W. Tate
- ‡Department of Chemistry, Imperial College London, London SW7 2AZ, U.K
| | | | - Katherine A. Brown
- †Division of Cell and Molecular Biology, Centre for Molecular Microbiology and Infection, Imperial College London, London SW7 2AZ, U.K
| | - Anthony A. Holder
- §Division of Parasitology, MRC National Institute for Medical Research, Mill Hill, London NW7 1AA, U.K
- Correspondence can be addressed to either of these authors (email or )
| | - Deborah F. Smith
- *Wellcome Trust Laboratories for Molecular Parasitology, Imperial College London, London SW7 2AZ, U.K
- †Division of Cell and Molecular Biology, Centre for Molecular Microbiology and Infection, Imperial College London, London SW7 2AZ, U.K
- ∥Immunology and Infection Unit, Department of Biology/Hull York Medical School, University of York, Heslington, York YO10 5YW, U.K
- Correspondence can be addressed to either of these authors (email or )
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42
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Lee SC, Shaw BD. A novel interaction between N-myristoylation and the 26S proteasome during cell morphogenesis. Mol Microbiol 2007; 63:1039-53. [PMID: 17238925 DOI: 10.1111/j.1365-2958.2006.05575.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
N-myristoylation is a protein lipidation event in which myristate is covalently linked to the N-terminal glycine of target proteins. In Aspergillus nidulans, the N-myristoylation deficient swoF1 mutant was previously shown to lose cell polarity during the early morphogenic event of germ tube emergence. To further investigate this defect, we mutagenized swoF1 and recovered six partial suppressors designated ssf (suppressor of swoF1). The secondary mutations enabled swoF1 to partially bypass its growth defect. We characterized a frame-shift mutation in ssfA1, which encodes an alpha subunit of the 20S core particle of the 26S proteasome. Fewer ubiquitinated proteins accumulated in the swoF1 mutant compared with wild-type. In contrast, the swoF1;ssfA1 mutant accumulated higher levels of ubiquitinated proteins than wild-type. The swoF1 mutant was bypassed in the presence of the proteasome inhibitor, MG132. These results demonstrate that the swoF1 phenotype was caused, at least in part, by an increased activity of 26S proteasome-dependent proteolysis and suppression occurred by attenuating the 26S proteasome activity. This is the first report linking N-myristoylation and ubiquitin-proteasome-dependent proteolysis during morphogenesis.
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Affiliation(s)
- Soo Chan Lee
- Program for the Biology of Filamentous Fungi, Department of Plant Pathology and Microbiology, Texas A&M University, 2132 TAMU, College Station, TX 77843, USA
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43
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Wu J, Tao Y, Zhang M, Howard MH, Gutteridge S, Ding J. Crystal structures of Saccharomyces cerevisiae N-myristoyltransferase with bound myristoyl-CoA and inhibitors reveal the functional roles of the N-terminal region. J Biol Chem 2007; 282:22185-94. [PMID: 17513302 DOI: 10.1074/jbc.m702696200] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Protein N-myristoylation catalyzed by myristoyl-CoA:protein N-myristoyltransferase (NMT) plays an important role in a variety of critical cellular processes and thus is an attractive target for development of antifungal drugs. We report here three crystal structures of Saccharomyces cerevisiae NMT: in binary complex with myristoyl-CoA (MYA) alone and in two ternary complexes involving MYA and two different non-peptidic inhibitors. In all three structures, the majority of the N-terminal region, absent in all previously reported structures, forms a well defined motif that is located in the vicinity of the peptide substrate-binding site and is involved in the binding of MYA. The Ab loop, which might be involved in substrate recognition, adopts an open conformation, whereas a loop of the N-terminal region (residues 22-24) that covers the top of the substrate-binding site is in the position occupied by the Ab loop when in the closed conformation. Structural comparisons with other NMTs, together with mutagenesis data, suggest that the N-terminal region of NMT plays an important role in the binding of both MYA and peptide substrate, but not in subsequent steps of the catalytic mechanism. The two inhibitors occupy the peptide substrate-binding site and interact with the protein through primarily hydrophobic contacts. Analyses of the inhibitorenzyme interactions provide valuable information for further improvement of antifungal inhibitors targeting NMT.
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Affiliation(s)
- Jian Wu
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
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44
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Sheng C, Zhu J, Zhang W, Zhang M, Ji H, Song Y, Xu H, Yao J, Miao Z, Zhou Y, Zhu J, Lü J. 3D-QSAR and molecular docking studies on benzothiazole derivatives as Candida albicans N-myristoyltransferase inhibitors. Eur J Med Chem 2006; 42:477-86. [PMID: 17349719 DOI: 10.1016/j.ejmech.2006.11.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2006] [Revised: 10/13/2006] [Accepted: 11/07/2006] [Indexed: 10/23/2022]
Abstract
N-Myristoyltransferase has been a promising new target for the design of novel antifungal agents with new mode of action. Molecular docking and three-dimensional quantitative structure-activity relationship (3D-QSAR) methods, CoMFA and CoMSIA, were applied to a set of novel benzothiazole Candida albicans N-myristoyltransferase (CaNmt) inhibitors. The binding mode of the compounds at the active site of CaNmt was explored using flexible docking method and various hydrophobic and hydrogen-bonding interactions were observed between the benzothiazole inhibitors and the target enzyme. The best CoMFA and CoMSIA models had a cross-validated coefficient q(2) of 0.733 and 0.738, respectively, which showed high correlative and predictive abilities on both the test set and training set. The 3D contour maps of CoMFA and CoMSIA provided smooth and interpretable explanation of the structure-activity relationship for the compounds. The analysis of the 3D contour plots permitted interesting conclusions about the effects of different substituent groups at different position of the benzothiazole ring, which will guide the design of novel CaNmt inhibitors with higher activity.
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Affiliation(s)
- Chunquan Sheng
- School of Pharmacy, Military Key Laboratory of Medicinal Chemistry, Second Military Medical University, 325 Guohe Road, Shanghai 200433, People's Republic of China
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45
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Walton FJ, Heitman J, Idnurm A. Conserved elements of the RAM signaling pathway establish cell polarity in the basidiomycete Cryptococcus neoformans in a divergent fashion from other fungi. Mol Biol Cell 2006; 17:3768-80. [PMID: 16775005 PMCID: PMC1556378 DOI: 10.1091/mbc.e06-02-0125] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2006] [Revised: 05/16/2006] [Accepted: 06/07/2006] [Indexed: 12/21/2022] Open
Abstract
In eukaryotes the complex processes of development, differentiation, and proliferation require carefully orchestrated changes in cellular morphology. Single-celled eukaryotes provide tractable models for the elucidation of signaling pathways involved in morphogenesis. Here we describe a pathway regulating cell polarization and separation in the human pathogenic fungus Cryptococcus neoformans. An insertional mutagenesis screen identified roles for the ARF1, CAP60, NDH1, KIC1, CBK1, SOG2, and TAO3 genes in establishing normal colony morphology. ARF1 and CAP60 are also required for capsule production, a virulence factor, and ARF1 confers resistance to the antifungal fluconazole. KIC1, CBK1, SOG2, and TAO3 are homologues of genes conserved in other eukaryotes; in Saccharomyces cerevisiae they constitute components of the RAM (regulation of Ace2p activity and cellular morphogenesis) signaling pathway. A targeted deletion of a fifth component of RAM (MOB2) conferred identical phenotypes to kic1, cbk1, sog2, or tao3 mutations. Characterization of these genes in C. neoformans revealed unique features of the RAM pathway in this organism. Loss of any of these genes caused constitutive hyperpolarization instead of the loss of polarity seen in S. cerevisiae. Furthermore, sensitivity to the drugs FK506 and cyclosporin A demonstrates that the RAM pathway acts in parallel with the protein phosphatase calcineurin in C. neoformans but not in S. cerevisiae. These results indicate that conserved signaling pathways serve both similar and divergent cellular roles in morphogenesis in these divergent organisms.
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Affiliation(s)
- Felicia J. Walton
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710
| | - Joseph Heitman
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710
| | - Alexander Idnurm
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710
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46
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Abstract
The ability of fungi to grow well at mammalian body temperatures is a fundamental characteristic of invasive human fungal pathogens. Cryptococcus neoformans, with its genetics, molecular biology, robust animal models and clinical importance, has become a premier fungal model system for molecular fungal pathogenesis studies. There has been over a half century of study into how C. neoformans grows at high temperatures. However, recently the understanding of high-temperature growth at a molecular level has dramatically accelerated. Many strategies have been used to identify genes and over a dozen genes have already been identified to be necessary for high-temperature growth. It is likely that there are many more to discover. It is clear that, as further studies understand how this encapsulated yeast is able to withstand the stresses of high temperature at a genetic and molecular basis, we will also know more about how it and other fungal pathogens have evolved into well-established human pathogens.
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Affiliation(s)
- John R Perfect
- Division of Infectious Diseases, Department of Medicine, Duke University Medical Center Durham, NC 27710, USA.
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47
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Goins CL, Gerik KJ, Lodge JK. Improvements to gene deletion in the fungal pathogen Cryptococcus neoformans: absence of Ku proteins increases homologous recombination, and co-transformation of independent DNA molecules allows rapid complementation of deletion phenotypes. Fungal Genet Biol 2006; 43:531-44. [PMID: 16714127 DOI: 10.1016/j.fgb.2006.02.007] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2005] [Revised: 02/25/2006] [Accepted: 02/28/2006] [Indexed: 11/20/2022]
Abstract
Cryptococcus neoformans is a pathogenic fungus that is relatively amenable to molecular genetic analysis, including gene deletion. However, rates of homologous recombination can be low, so obtaining specific gene deletion transformants is challenging. We have utilized two new technologies, cku deletion strains to improve the efficiency of gene deletions in this organism, and co-transformations. The Ku70-Ku80 heterodimer is predicted to be an essential part of the non-homologous end-joining process in C. neoformans. Here we show that a deletion in one or both of these proteins results in an increase in the rates of homologous recombination. Importantly, we demonstrate that after generation of a strain with a particular deletion of interest, the cku deletion can be removed by mating and segregation. We also utilize co-transformation of wild-type genes and selectable markers on separate linear DNA molecules to complement a deletion event. We show that co-transformation results in the successful restoration of wild-type phenotype, though variations in this phenotype often occur.
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Affiliation(s)
- Chelsey L Goins
- Edward A Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, 1402 S Grand Boulevard, MO 63104, USA
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48
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Hu G, Kronstad JW. Gene disruption in Cryptococcus neoformans and Cryptococcus gattii by in vitro transposition. Curr Genet 2006; 49:341-50. [PMID: 16397763 DOI: 10.1007/s00294-005-0054-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2005] [Revised: 12/07/2005] [Accepted: 12/10/2005] [Indexed: 01/19/2023]
Abstract
Cryptococcus neoformans and Cryptococcus gattii are basidiomycetous fungi that infect immunocompromised and immunocompetent people. We developed an insertional mutagenesis strategy for these species based on in vitro transposition and we tested the method by disrupting the URA5 gene in a strain of C. neoformans and the CAP10 gene in three strains of C. gattii. We targeted plasmid DNA containing the URA5 gene or plasmid DNA containing the CAP10 gene from genomic libraries from the shotgun sequencing project for the C. gatti strain WM276. In the latter case, the availability of the end sequences of the clones from the assembled genomic sequence allows rapid selection of target genes for disruption. Modified transposons containing the nourseothricin (NAT) or neomycin (Neo) resistance cassettes were randomly inserted into the target DNA by in vitro transposition. The disrupted genes were used for biolistic transformation and homologous integration was subsequently confirmed by PCR and Southern blot analysis. These results demonstrate that the emerging genomic resources, combined with in vitro transposition into plasmid DNAs from shotgun sequencing libraries or cloned PCR products, will facilitate high-throughput genetic analysis in Cryptococcus species.
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Affiliation(s)
- Guanggan Hu
- The Michael Smith Laboratories, The University of British Columbia, 2185 East Mall, Vancouver, BC, Canada, V6T 1Z4.
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49
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Abstract
Comparative analyses of fungal genomes and molecular research on genes associated with fungal viability and virulence has led to the identification of many putative targets for novel antifungal agents. So far the rational approach to antifungal discovery, in which compounds are optimized against an individual target then progressed to efficacy against intact fungi and ultimately to infected humans has delivered no new agents. However, the approach continues to hold promise for the future. This review critically assesses the molecular target-based approach to antifungal discovery, outlines problems and pitfalls inherent in the genomics and target discovery strategies and describes the status of heavily investigated examples of target-based research.
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Affiliation(s)
- Frank C Odds
- Aberdeen Fungal Group, Institute of Medical Sciences, Department of Molecular and Cell Biology, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, Scotland, UK.
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50
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Idnurm A, Bahn YS, Nielsen K, Lin X, Fraser JA, Heitman J. Deciphering the model pathogenic fungus Cryptococcus neoformans. Nat Rev Microbiol 2005; 3:753-64. [PMID: 16132036 DOI: 10.1038/nrmicro1245] [Citation(s) in RCA: 244] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cryptococcus neoformans is a basidiomycete fungal pathogen of humans that has diverged considerably from other model fungi such as Neurospora crassa, Aspergillus nidulans, Saccharomyces cerevisiae and the common human fungal pathogen Candida albicans. The recent completion of the genome sequences of two related C. neoformans strains and the ongoing genome sequencing of three other divergent Cryptococcus strains with different virulence phenotypes and environmental distributions should improve our understanding of this important pathogen. We discuss the biology of C. neoformans in light of this genomic data, with a special emphasis on the role that evolution and sexual reproduction have in the complex relationships of the fungus with the environment and the host.
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Affiliation(s)
- Alexander Idnurm
- Department of Molecular Genetics and Microbiology, Howard Hughes Medical Institute, Duke University Medical Center, Durham, North Carolina 27710, USA
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