1
|
David H, Solomon AP. Molecular association of Candida albicans and vulvovaginal candidiasis: focusing on a solution. Front Cell Infect Microbiol 2023; 13:1245808. [PMID: 37900321 PMCID: PMC10611527 DOI: 10.3389/fcimb.2023.1245808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 09/21/2023] [Indexed: 10/31/2023] Open
Abstract
Candida albicans-mediated vulvovaginal candidiasis (VVC) is a significant challenge in clinical settings, owing to the inefficacy of current antifungals in modulating virulence, development of resistance, and poor penetration into the biofilm matrix. Various predisposition factors are molecular drivers that lead to the dysbiosis of normal microflora of the vagina, upregulation of central metabolic pathways, morphogenesis, hyphal extension, adhesion, invasion, and biofilm formation leading to chronic infection and recurrence. Hence, it is crucial to understand the molecular mechanism behind the virulence pathways driven by those drivers to decode the drug targets. Finding innovative solutions targeting fungal virulence/biofilm may potentiate the antifungals at low concentrations without affecting the recurrence of resistance. With this background, the present review details the critical molecular drivers and associated network of virulence pathways, possible drug targets, target-specific inhibitors, and probable mode of drug delivery to cross the preclinical phase by appropriate in vivo models.
Collapse
Affiliation(s)
| | - Adline Princy Solomon
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India
| |
Collapse
|
2
|
Pinder C, Lebedinec R, Levine TP, Birch M, Oliver JD. Characterisation of putative class 1A DHODH-like proteins from Mucorales and dematiaceous mould species. PLoS One 2023; 18:e0289441. [PMID: 37531380 PMCID: PMC10395836 DOI: 10.1371/journal.pone.0289441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 07/19/2023] [Indexed: 08/04/2023] Open
Abstract
Olorofim is a new antifungal in clinical development which has a novel mechanism of action against dihydroorotate dehydrogenase (DHODH). DHODH form a ubiquitous family of enzymes in the de novo pyrimidine biosynthetic pathway and are split into class 1A, class 1B and class 2. Olorofim specifically targets the fungal class 2 DHODH present in a range of pathogenic moulds. The nature and number of DHODH present in many fungal species have not been addressed for large clades of this kingdom. Mucorales species do not respond to olorofim; previous work suggests they have only class 1A DHODH and so lack the class 2 target that olorofim inhibits. The dematiaceous moulds have mixed susceptibility to olorofim, yet previous analyses imply that they have class 2 DHODH. As this is at odds with their intermediate susceptibility to olorofim, we hypothesised that these pathogens may maintain a second class of DHODH, facilitating pyrimidine biosynthesis in the presence of olorofim. The aim of this study was to investigate the DHODH repertoire of clinically relevant species of Mucorales and dematiaceous moulds to further characterise these pathogens and understand variations in olorofim susceptibility. Using bioinformatic analysis, S. cerevisiae complementation and biochemical assays of recombinant protein, we provide the first evidence that two representative members of the Mucorales have only class 1A DHODH, substantiating a lack of olorofim susceptibility. In contrast, bioinformatic analyses initially suggested that seven dematiaceous species appeared to harbour both class 1A-like and class 2-like DHODH genes. However, further experimental investigation of the putative class 1A-like genes through yeast complementation and biochemical assays characterised them as dihydrouracil oxidases rather than DHODHs. These data demonstrate variation in dematiaceous mould olorofim susceptibility is not due to a secondary DHODH and builds on the growing picture of fungal dihydrouracil oxidases as an example of horizontal gene transfer.
Collapse
Affiliation(s)
| | | | - Tim P Levine
- UCL Institute of Ophthalmology, London, United Kingdom
| | | | | |
Collapse
|
3
|
Sousa FM, Pires P, Barreto A, Refojo PN, Silva MS, Fernandes PB, Carapeto AP, Robalo TT, Rodrigues MS, Pinho MG, Cabrita EJ, Pereira MM. Unveiling the membrane bound dihydroorotate: Quinone oxidoreductase from Staphylococcus aureus. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2023; 1864:148948. [PMID: 36481274 DOI: 10.1016/j.bbabio.2022.148948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 11/23/2022] [Accepted: 11/28/2022] [Indexed: 12/12/2022]
Abstract
Staphylococcus aureus is an opportunistic pathogen and one of the most frequent causes for community acquired and nosocomial bacterial infections. Even so, its energy metabolism is still under explored and its respiratory enzymes have been vastly overlooked. In this work, we unveil the dihydroorotate:quinone oxidoreductase (DHOQO) from S. aureus, the first example of a DHOQO from a Gram-positive organism. This protein was shown to be a FMN containing menaquinone reducing enzyme, presenting a Michaelis-Menten behaviour towards the two substrates, which was inhibited by Brequinar, Leflunomide, Lapachol, HQNO, Atovaquone and TFFA with different degrees of effectiveness. Deletion of the DHOQO coding gene (Δdhoqo) led to lower bacterial growth rates, and effected in cell morphology and metabolism, most importantly in the pyrimidine biosynthesis, here systematized for S. aureus MW2 for the first time. This work unveils the existence of a functional DHOQO in the respiratory chain of the pathogenic bacterium S. aureus, enlarging the understanding of its energy metabolism.
Collapse
Affiliation(s)
- Filipe M Sousa
- Instituto de Tecnologia Química e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157 Oeiras, Portugal; University of Lisbon, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Campo Grande, C8, 1749-016 Lisboa, Portugal
| | - Patrícia Pires
- University of Lisbon, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Campo Grande, C8, 1749-016 Lisboa, Portugal
| | - Andreia Barreto
- University of Lisbon, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Campo Grande, C8, 1749-016 Lisboa, Portugal
| | - Patrícia N Refojo
- Instituto de Tecnologia Química e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157 Oeiras, Portugal
| | - Micael S Silva
- UCIBIO, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
| | - Pedro B Fernandes
- Instituto de Tecnologia Química e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157 Oeiras, Portugal
| | - Ana P Carapeto
- University of Lisbon, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Campo Grande, C8, 1749-016 Lisboa, Portugal; Departamento de Física, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
| | - Tiago T Robalo
- University of Lisbon, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Campo Grande, C8, 1749-016 Lisboa, Portugal; Departamento de Física, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
| | - Mário S Rodrigues
- University of Lisbon, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Campo Grande, C8, 1749-016 Lisboa, Portugal; Departamento de Física, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
| | - Mariana G Pinho
- Instituto de Tecnologia Química e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157 Oeiras, Portugal
| | - Eurico J Cabrita
- UCIBIO, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
| | - Manuela M Pereira
- Instituto de Tecnologia Química e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157 Oeiras, Portugal; University of Lisbon, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Campo Grande, C8, 1749-016 Lisboa, Portugal.
| |
Collapse
|
4
|
Higashimura N, Hamada A, Banba S. Novel fungicide quinofumelin shows selectivity for fungal dihydroorotate dehydrogenase over the corresponding human enzyme. JOURNAL OF PESTICIDE SCIENCE 2023; 48:17-21. [PMID: 36874638 PMCID: PMC9978249 DOI: 10.1584/jpestics.d22-035] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 11/23/2022] [Indexed: 06/18/2023]
Abstract
The species selectivity of class 2 dihydroorotate dehydrogenase (DHODH), a target enzyme for quinofumelin, was examined. The Homo sapiens DHODH (HsDHODH) assay system was developed to compare the selectivity of quinofumelin for fungi with that for mammals. The IC50 values of quinofumelin for Pyricularia oryzae DHODH (PoDHODH) and HsDHODH were 2.8 nM and >100 µM, respectively. Quinofumelin was highly selective for fungal over human DHODH. Additionally, we constructed recombinant P. oryzae mutants where PoDHODH (PoPYR4) or HsDHODH was inserted into the PoPYR4 disruption mutant. At quinofumelin concentration of 0.01-1 ppm, the PoPYR4 insertion mutants could not grow, but the HsDHODH gene-insertion mutants thrived. This indicates that HsDHODH is a substitute for PoDHODH, and quinofumelin could not inhibit HsDHODH as in the HsDHODH enzyme assay. Comparing the amino acid sequences of human and fungal DHODHs indicates that the significant difference at the ubiquinone-binding site contributes to the species selectivity of quinofumelin.
Collapse
Affiliation(s)
| | - Akira Hamada
- Agrochemicals Research Center, Mitsui Chemicals Agro, Inc
| | - Shinichi Banba
- Agrochemicals Research Center, Mitsui Chemicals Agro, Inc
| |
Collapse
|
5
|
Higashimura N, Hamada A, Ohara T, Sakurai S, Ito H, Banba S. The target site of the novel fungicide quinofumelin, Pyricularia oryzae class II dihydroorotate dehydrogenase. JOURNAL OF PESTICIDE SCIENCE 2022; 47:190-196. [PMID: 36514691 PMCID: PMC9716045 DOI: 10.1584/jpestics.d22-027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 08/24/2022] [Indexed: 06/17/2023]
Abstract
The target site of the novel fungicide quinofumelin was investigated in the rice blast fungus Pyricularia oryzae. Quinofumelin-induced mycelial growth inhibition was reversed by orotate but not by dihydroorotate. Recovery tests suggested that the target site of quinofumelin was dihydroorotate dehydrogenase (DHODH), which catalyzes the oxidation of dihydroorotate to orotate. Quinofumelin strongly inhibited P. oryzae class 2 DHODH (DHODH II) (IC50: 2.8 nM). The inhibitory activities of mycelial growth and DHODH II were strongly positively correlated, indicating that DHODH II inhibition by quinofumelin lead to antifungal activity. A P. oryzae DHODH II gene (PoPYR4) disruption mutant (ΔPopyr4), showing the same tendency as the quinofumelin-treated wild strain in recovery tests, was constructed, and disease symptoms were not observed in rice plants infected by ΔPopyr4. Thus, DHODH II, which plays an important role in pathogenicity and mycelial growth, is found to be the target site of quinofumelin.
Collapse
Affiliation(s)
| | - Akira Hamada
- Agrochemicals Research Center, Mitsui Chemicals Agro, Inc
| | - Toshiaki Ohara
- Agrochemicals Research Center, Mitsui Chemicals Agro, Inc
| | | | - Hiroyuki Ito
- Agrochemicals Research Center, Mitsui Chemicals Agro, Inc
| | - Shinichi Banba
- Agrochemicals Research Center, Mitsui Chemicals Agro, Inc
| |
Collapse
|
6
|
Zhen C, Lu H, Jiang Y. Novel Promising Antifungal Target Proteins for Conquering Invasive Fungal Infections. Front Microbiol 2022; 13:911322. [PMID: 35783432 PMCID: PMC9243655 DOI: 10.3389/fmicb.2022.911322] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Accepted: 05/24/2022] [Indexed: 11/26/2022] Open
Abstract
Invasive fungal infections (IFIs) pose a serious clinical problem, but the antifungal arsenal is limited and has many disadvantages, such as drug resistance and toxicity. Hence, there is an urgent need to develop antifungal compounds that target novel target proteins of pathogenic fungi for treating IFIs. This review provides a comprehensive summary of the biological functions of novel promising target proteins for treating IFIs in pathogenic fungi and their inhibitors. Inhibitors of inositol phosphoramide (IPC) synthases (such as Aureobasidin A, Khafrefungin, Galbonolide A, and Pleofungin A) have potent antifungal activities by inhibiting sphingolipid synthesis. Disrupting glycosylphosphatidylinositol (GPI) biosynthesis by Jawsamycin (an inhibitor of Spt14), M720 (an inhibitor of Mcd4), and APX001A (an inhibitor of Gwt1) is a promising strategy for treating IFIs. Turbinmicin is a natural-compound inhibitor of Sec14 and has extraordinary antifungal efficacy, broad-antifungal spectrum, low toxicity, and is a promising new compound for treating IFIs. CMLD013075 targets fungal heat shock protein 90 (Hsp90) and has remarkable antifungal efficacy. Olorofim, as an inhibitor of dihydrolactate dehydrogenase, is a breakthrough drug treatment for IFIs. These novel target proteins and their inhibitors may overcome the limitations of currently available antifungal drugs and improve patient outcomes in the treatment of IFIs.
Collapse
|
7
|
Bouwknegt J, Koster CC, Vos AM, Ortiz-Merino RA, Wassink M, Luttik MAH, van den Broek M, Hagedoorn PL, Pronk JT. Class-II dihydroorotate dehydrogenases from three phylogenetically distant fungi support anaerobic pyrimidine biosynthesis. Fungal Biol Biotechnol 2021; 8:10. [PMID: 34656184 PMCID: PMC8520639 DOI: 10.1186/s40694-021-00117-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 10/02/2021] [Indexed: 11/10/2022] Open
Abstract
Background In most fungi, quinone-dependent Class-II dihydroorotate dehydrogenases (DHODs) are essential for pyrimidine biosynthesis. Coupling of these Class-II DHODHs to mitochondrial respiration makes their in vivo activity dependent on oxygen availability. Saccharomyces cerevisiae and closely related yeast species harbor a cytosolic Class-I DHOD (Ura1) that uses fumarate as electron acceptor and thereby enables anaerobic pyrimidine synthesis. Here, we investigate DHODs from three fungi (the Neocallimastigomycete Anaeromyces robustus and the yeasts Schizosaccharomyces japonicus and Dekkera bruxellensis) that can grow anaerobically but, based on genome analysis, only harbor a Class-II DHOD. Results Heterologous expression of putative Class-II DHOD-encoding genes from fungi capable of anaerobic, pyrimidine-prototrophic growth (Arura9, SjURA9, DbURA9) in an S. cerevisiae ura1Δ strain supported aerobic as well as anaerobic pyrimidine prototrophy. A strain expressing DbURA9 showed delayed anaerobic growth without pyrimidine supplementation. Adapted faster growing DbURA9-expressing strains showed mutations in FUM1, which encodes fumarase. GFP-tagged SjUra9 and DbUra9 were localized to S. cerevisiae mitochondria, while ArUra9, whose sequence lacked a mitochondrial targeting sequence, was localized to the yeast cytosol. Experiments with cell extracts showed that ArUra9 used free FAD and FMN as electron acceptors. Expression of SjURA9 in S. cerevisiae reproducibly led to loss of respiratory competence and mitochondrial DNA. A cysteine residue (C265 in SjUra9) in the active sites of all three anaerobically active Ura9 orthologs was shown to be essential for anaerobic activity of SjUra9 but not of ArUra9. Conclusions Activity of fungal Class-II DHODs was long thought to be dependent on an active respiratory chain, which in most fungi requires the presence of oxygen. By heterologous expression experiments in S. cerevisiae, this study shows that phylogenetically distant fungi independently evolved Class-II dihydroorotate dehydrogenases that enable anaerobic pyrimidine biosynthesis. Further structure–function studies are required to understand the mechanistic basis for the anaerobic activity of Class-II DHODs and an observed loss of respiratory competence in S. cerevisiae strains expressing an anaerobically active DHOD from Sch. japonicus. Supplementary Information The online version contains supplementary material available at 10.1186/s40694-021-00117-4.
Collapse
Affiliation(s)
- Jonna Bouwknegt
- Department of Biotechnology, Delft University of Technology, van der Maasweg 9, 2629 HZ, Delft, The Netherlands
| | - Charlotte C Koster
- Department of Biotechnology, Delft University of Technology, van der Maasweg 9, 2629 HZ, Delft, The Netherlands
| | - Aurin M Vos
- Wageningen Plant Research, Wageningen University and Research, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands
| | - Raúl A Ortiz-Merino
- Department of Biotechnology, Delft University of Technology, van der Maasweg 9, 2629 HZ, Delft, The Netherlands
| | - Mats Wassink
- Department of Biotechnology, Delft University of Technology, van der Maasweg 9, 2629 HZ, Delft, The Netherlands
| | - Marijke A H Luttik
- Department of Biotechnology, Delft University of Technology, van der Maasweg 9, 2629 HZ, Delft, The Netherlands
| | - Marcel van den Broek
- Department of Biotechnology, Delft University of Technology, van der Maasweg 9, 2629 HZ, Delft, The Netherlands
| | - Peter L Hagedoorn
- Department of Biotechnology, Delft University of Technology, van der Maasweg 9, 2629 HZ, Delft, The Netherlands
| | - Jack T Pronk
- Department of Biotechnology, Delft University of Technology, van der Maasweg 9, 2629 HZ, Delft, The Netherlands.
| |
Collapse
|
8
|
Label free-based proteomic analysis of the food spoiler Pseudomonas fluorescens response to lactobionic acid by SWATH-MS. Food Control 2021. [DOI: 10.1016/j.foodcont.2020.107834] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
9
|
Löffler M, Carrey EA, Knecht W. The pathway to pyrimidines: The essential focus on dihydroorotate dehydrogenase, the mitochondrial enzyme coupled to the respiratory chain. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2020; 39:1281-1305. [PMID: 32043431 DOI: 10.1080/15257770.2020.1723625] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
This paper is based on the Anne Simmonds Memorial Lecture, given by Monika Löffler at the International Symposium on Purine and Pyrimidine Metabolism in Man, Lyon 2019. It is dedicated to H. Anne Simmonds (died 2010) - a founding member of the ESSPPMM, since 2003 Purine and Pyrimidine Society - and her outstanding contributions to the identification and study of inborn errors of purine and pyrimidine metabolism. The distinctive intracellular arrangement of pyrimidine de novo synthesis in higher eukaryotes is important to cells with a high demand for nucleic acid synthesis. The proximity of the enzyme active sites and the resulting channeling in CAD and UMP synthase is of kinetic benefit. The intervening enzyme dihydroorotate dehydrogenase (DHODH) is located in the mitochondrion with access to the ubiquinone pool, thus ensuring efficient removal of redox equivalents through the constitutive activity of the respiratory chain, also a mechanism through which the input of 2 ATP for carbamylphosphate synthesis is balanced by Oxphos. The obligatory contribution of O2 to de novo UMP synthesis means that DHODH has a pivotal role in adapting the proliferative capacity of cells to different conditions of oxygenation, such as hypoxia in growing tumors. DHODH also is a validated drug target in inflammatory diseases. This survey of selected topics of personal interest and reflection spans some 40 years of our studies from tumor cell cultures under hypoxia to in vitro assays including purification from mitochondria, localization, cloning, expression, biochemical characterization, crystallisation, kinetics and inhibition patterns of eukaryotic DHODH enzymes.
Collapse
Affiliation(s)
- Monika Löffler
- Institute of Physiological Chemistry, Faculty of Medicine, Philipps-University Marburg, Marburg, Germany
| | | | - Wolfgang Knecht
- Department of Biology & Lund Protein Production Platform, Lund University, Lund, Sweden
| |
Collapse
|
10
|
Dihydroorotate dehydrogenase inhibitors in anti-infective drug research. Eur J Med Chem 2019; 183:111681. [PMID: 31557612 DOI: 10.1016/j.ejmech.2019.111681] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 08/01/2019] [Accepted: 09/05/2019] [Indexed: 01/08/2023]
Abstract
Pyrimidines are essential for the cell survival and proliferation of living parasitic organisms, such as Helicobacter pylori, Plasmodium falciparum and Schistosoma mansoni, that are able to impact upon human health. Pyrimidine building blocks, in human cells, are synthesised via both de novo biosynthesis and salvage pathways, the latter of which is an effective way of recycling pre-existing nucleotides. As many parasitic organisms lack pyrimidine salvage pathways for pyrimidine nucleotides, blocking de novo biosynthesis is seen as an effective therapeutic means to selectively target the parasite without effecting the human host. Dihydroorotate dehydrogenase (DHODH), which is involved in the de novo biosynthesis of pyrimidines, is a validated target for anti-infective drug research. Recent advances in the DHODH microorganism field are discussed herein, as is the potential for the development of DHODH-targeted therapeutics.
Collapse
|
11
|
Garavito MF, Narvaez-Ortiz HY, Pulido DC, Löffler M, Judelson HS, Restrepo S, Zimmermann BH. Phytophthora infestans Dihydroorotate Dehydrogenase Is a Potential Target for Chemical Control - A Comparison With the Enzyme From Solanum tuberosum. Front Microbiol 2019; 10:1479. [PMID: 31316493 PMCID: PMC6611227 DOI: 10.3389/fmicb.2019.01479] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 06/13/2019] [Indexed: 01/04/2023] Open
Abstract
The oomycete Phytophthora infestans is the causal agent of tomato and potato late blight, a disease that causes tremendous economic losses in the production of solanaceous crops. The similarities between oomycetes and the apicomplexa led us to hypothesize that dihydroorotate dehydrogenase (DHODH), the enzyme catalyzing the fourth step in pyrimidine biosynthetic pathway, and a validated drug target in treatment of malaria, could be a potential target for controlling P. infestans growth. In eukaryotes, class 2 DHODHs are mitochondrially associated ubiquinone-linked enzymes that catalyze the fourth, and only redox step of de novo pyrimidine biosynthesis. We characterized the enzymes from both the pathogen and a host, Solanum tuberosum. Plant DHODHs are known to be class 2 enzymes. Sequence analysis suggested that the pathogen enzyme (PiDHODHs) also belongs to this class. We confirmed the mitochondrial localization of GFP-PiDHODH showing colocalization with mCherry-labeled ATPase in a transgenic pathogen. N-terminally truncated versions of the two DHODHs were overproduced in E. coli, purified, and kinetically characterized. StDHODH exhibited a apparent specific activity of 41 ± 1 μmol min-1 mg-1, a kcatapp of 30 ± 1 s-1, and a Kmapp of 20 ± 1 μM for L-dihydroorotate, and a Kmapp= 30 ± 3 μM for decylubiquinone (Qd). PiDHODH exhibited an apparent specific activity of 104 ± 1 μmol min-1 mg-1, a kcatapp of 75 ± 1 s-1, and a Kmapp of 57 ± 3 μM for L-dihydroorotate, and a Kmapp of 15 ± 1 μM for Qd. The two enzymes exhibited different activities with different quinones and napthoquinone derivatives, and different sensitivities to compounds known to cause inhibition of DHODHs from other organisms. The IC50 for A77 1726, a nanomolar inhibitor of human DHODH, was 2.9 ± 0.6 mM for StDHODH, and 79 ± 1 μM for PiDHODH. In vivo, 0.5 mM A77 1726 decreased mycelial growth by approximately 50%, after 92 h. Collectively, our findings suggest that the PiDHODH could be a target for selective inhibitors and we provide a biochemical background for the development of compounds that could be helpful for the control of the pathogen, opening the way to protein crystallization.
Collapse
Affiliation(s)
- Manuel F Garavito
- Departamento de Ciencias Biológicas, Universidad de los Andes, Bogotá, Colombia.,Laboratorio de Micología y Fitopatología, Universidad de los Andes, Bogotá, Colombia
| | | | - Dania Camila Pulido
- Departamento de Ciencias Biológicas, Universidad de los Andes, Bogotá, Colombia
| | - Monika Löffler
- Faculty of Medicine, Department of Biology, University of Marburg, Marburg, Germany
| | - Howard S Judelson
- Department of Microbiology and Plant Pathology, University of California, Riverside, Riverside, CA, United States
| | - Silvia Restrepo
- Laboratorio de Micología y Fitopatología, Universidad de los Andes, Bogotá, Colombia
| | | |
Collapse
|
12
|
Sahu U, Rajendra VKH, Kapnoor SS, Bhagavat R, Chandra N, Rangarajan PN. Methionine synthase is localized to the nucleus in Pichia pastoris and Candida albicans and to the cytoplasm in Saccharomyces cerevisiae. J Biol Chem 2017; 292:14730-14746. [PMID: 28701466 DOI: 10.1074/jbc.m117.783019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 07/10/2017] [Indexed: 11/06/2022] Open
Abstract
Methionine synthase (MS) catalyzes methylation of homocysteine, the last step in the biosynthesis of methionine, which is essential for the regeneration of tetrahydrofolate and biosynthesis of S-adenosylmethionine. Here, we report that MS is localized to the nucleus of Pichia pastoris and Candida albicans but is cytoplasmic in Saccharomyces cerevisiae The P. pastoris strain carrying a deletion of the MET6 gene encoding MS (Ppmet6) exhibits methionine as well as adenine auxotrophy indicating that MS is required for methionine as well as adenine biosynthesis. Nuclear localization of P. pastoris MS (PpMS) was abrogated by the deletion of 107 C-terminal amino acids or the R742A mutation. In silico analysis of the PpMS structure indicated that PpMS may exist in a dimer-like configuration in which Arg-742 of a monomer forms a salt bridge with Asp-113 of another monomer. Biochemical studies indicate that R742A as well as D113R mutations abrogate nuclear localization of PpMS and its ability to reverse methionine auxotrophy of Ppmet6 Thus, association of two PpMS monomers through the interaction of Arg-742 and Asp-113 is essential for catalytic activity and nuclear localization. When PpMS is targeted to the cytoplasm employing a heterologous nuclear export signal, it is expressed at very low levels and is unable to reverse methionine and adenine auxotrophy of Ppmet6 Thus, nuclear localization is essential for the stability and function of MS in P. pastoris. We conclude that nuclear localization of MS is a unique feature of respiratory yeasts such as P. pastoris and C. albicans, and it may have novel moonlighting functions in the nucleus.
Collapse
Affiliation(s)
- Umakant Sahu
- From the Department of Biochemistry, Indian Institute of Science, Bangalore 560012, India
| | - Vinod K H Rajendra
- From the Department of Biochemistry, Indian Institute of Science, Bangalore 560012, India
| | - Shankar S Kapnoor
- From the Department of Biochemistry, Indian Institute of Science, Bangalore 560012, India
| | - Raghu Bhagavat
- From the Department of Biochemistry, Indian Institute of Science, Bangalore 560012, India
| | - Nagasuma Chandra
- From the Department of Biochemistry, Indian Institute of Science, Bangalore 560012, India
| | - Pundi N Rangarajan
- From the Department of Biochemistry, Indian Institute of Science, Bangalore 560012, India
| |
Collapse
|
13
|
Reis RAG, Calil FA, Feliciano PR, Pinheiro MP, Nonato MC. The dihydroorotate dehydrogenases: Past and present. Arch Biochem Biophys 2017; 632:175-191. [PMID: 28666740 DOI: 10.1016/j.abb.2017.06.019] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 06/23/2017] [Accepted: 06/26/2017] [Indexed: 01/24/2023]
Abstract
The flavoenzyme dihydroorotate dehydrogenase catalyzes the stereoselective oxidation of (S)-dihydroorotate to orotate in the fourth of the six conserved enzymatic reactions involved in the de novo pyrimidine biosynthetic pathway. Inhibition of pyrimidine metabolism by selectively targeting DHODHs has been exploited in the development of new therapies against cancer, immunological disorders, bacterial and viral infections, and parasitic diseases. Through a chronological narrative, this review summarizes the efforts of the scientific community to achieve our current understanding of structural and biochemical properties of DHODHs. It also attempts to describe the latest advances in medicinal chemistry for therapeutic development based on the selective inhibition of DHODH, including an overview of the experimental techniques used for ligand screening during the process of drug discovery.
Collapse
Affiliation(s)
- Renata A G Reis
- Department of Chemistry, Georgia State University, Atlanta, GA 30302, United States
| | - Felipe Antunes Calil
- Laboratório de Cristalografia de Proteínas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, 14040-903, Brazil
| | - Patricia Rosa Feliciano
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - Matheus Pinto Pinheiro
- Brazilian Biosciences National Laboratory (LNBio), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, Sao Paulo, 13083-970, Brazil
| | - M Cristina Nonato
- Laboratório de Cristalografia de Proteínas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, 14040-903, Brazil.
| |
Collapse
|
14
|
Fluorescence assay of dihydroorotate dehydrogenase that may become a cancer biomarker. Sci Rep 2017; 7:40670. [PMID: 28084471 PMCID: PMC5233952 DOI: 10.1038/srep40670] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 12/09/2016] [Indexed: 12/03/2022] Open
Abstract
We developed an assay method for measuring dihydroorotate dehydrogenase (DHODH) activity in cultured HeLa cells and fibroblasts, and in stage III stomach cancer and adjacent normal tissues from the same patient. The assay comprised enzymatic reaction of DHODH with a large amount of dihydroorotic acid substrate, followed by fluorescence (FL) detection specific for orotic acid using the 4-trifluoromethyl-benzamidoxime fluorogenic reagent. The DHODH activities in the biologically complex samples were readily measured by the assay method. Our data indicate significantly higher DHODH activity in HeLa cells (340 ± 25.9 pmol/105 cells/h) than in normal fibroblasts (54.1 ± 7.40 pmol/105 cells/h), and in malignant tumour tissue (1.10 ± 0.19 nmol/mg total proteins/h) than in adjacent normal tissue (0.24 ± 0.11 nmol/mg total proteins/h). This is the first report that DHODH activity may be a diagnostic biomarker for cancer.
Collapse
|
15
|
Victoria Castelli M, Gabriel Derita M, Noelí López S. Novel antifungal agents: a patent review (2013 - present). Expert Opin Ther Pat 2016; 27:415-426. [DOI: 10.1080/13543776.2017.1261113] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- María Victoria Castelli
- Universidad Nacional de Rosario, CONICET, Farmacognosia, Facultad de Ciencias Bioquímicas y Farmacéuticas, Rosario, Santa Fe, Argentina
| | - Marcos Gabriel Derita
- Universidad Nacional de Rosario, CONICET, Farmacognosia, Facultad de Ciencias Bioquímicas y Farmacéuticas, Rosario, Santa Fe, Argentina
- Universidad Nacional del Litoral, CONICET, Cátedra de Cultivos Intensivos, Facultad de Ciencias Agrarias, Esperanza, Santa Fe, Argentina
| | - Silvia Noelí López
- Universidad Nacional de Rosario, CONICET, Farmacognosia, Facultad de Ciencias Bioquímicas y Farmacéuticas, Rosario, Santa Fe, Argentina
| |
Collapse
|
16
|
Banerjee D, Umland TC, Panepinto JC. De Novo Pyrimidine Biosynthesis Connects Cell Integrity to Amphotericin B Susceptibility in Cryptococcus neoformans. mSphere 2016; 1:e00191-16. [PMID: 27904878 PMCID: PMC5112334 DOI: 10.1128/msphere.00191-16] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 10/24/2016] [Indexed: 11/20/2022] Open
Abstract
The use of amphotericin B (AmB) in conjunction with 5-fluorocytosine (5-FC) is known to be the optimal therapy for treating cryptococcosis, but the mechanism by which 5-FC synergizes with AmB is unknown. In this study, we generated a Cryptococcus neoformans ura1Δ mutant lacking dihydroorotate dehydrogenase (DHODH), which demonstrated temperature-sensitive growth due to a defect in cell integrity and sensitivity to cell wall-damaging agents. In addition, sensitivity to AmB was greatly increased. Inclusion of uracil or uridine in the medium did not suppress the cell wall or AmB phenotype, whereas complementation with the wild-type URA1 gene complemented the mutant phenotype. As a measure of membrane accessibility, we assayed the rate of association of the lipid-binding dye 3,3'-dihexyloxacarbocyanine iodide (DiOC6) and saw more rapid association in the ura1Δ mutant. We likewise saw an increased rate of DiOC6 association in other AmB-sensitive mutants, including a ura- spontaneous URA5 mutant made by 5-fluoroorotic acid (5-FOA) selection and a bck1Δ mutant defective in cell integrity signaling. Similar results were also obtained by using a specific plasma membrane-binding CellMask live stain, with cell integrity mutants that exhibited increased and faster association of the dye with the membrane. Chitin synthase mutants (chs5Δ and chs6Δ) that lack any reported cell wall defects, in turn, demonstrate neither any increased susceptibility to AmB nor a greater accessibility to either of the dyes. Finally, perturbation of the cell wall of the wild type by treatment with the β-1,6-glucan synthase inhibitor caspofungin was synergistic with AmB in vitro. IMPORTANCE Synergy between AmB and nucleotide biosynthetic pathways has been documented, but the mechanism of this interaction has not been delineated. Results from this study suggest a correlation between uridine nucleotide biosynthesis and cell integrity likely mediated through the pool of nucleotide-sugar conjugates, which are precursor molecules for both capsule and cell wall of C. neoformans. Thus, we propose a mechanism by which structural defects in the cell wall resulting from perturbation of pyrimidine biosynthesis allow faster and increased penetration of AmB molecules into the cell membrane. Overall, our work demonstrates that impairment of pyrimidine biosynthesis in C. neoformans could be a potential target for antifungal therapy, either alone or in combination with AmB.
Collapse
Affiliation(s)
- Dithi Banerjee
- Department of Microbiology and Immunology, Witebsky Center for Microbial Pathogenesis and Immunology, University at Buffalo, The State University of New York, Buffalo, New York, USA
| | - Timothy C. Umland
- Department of Structural Biology, Hauptman Woodward Medical Research Institute, University at Buffalo, The State University of New York, Buffalo, New York, USA
| | - John C. Panepinto
- Department of Microbiology and Immunology, Witebsky Center for Microbial Pathogenesis and Immunology, University at Buffalo, The State University of New York, Buffalo, New York, USA
| |
Collapse
|
17
|
F901318 represents a novel class of antifungal drug that inhibits dihydroorotate dehydrogenase. Proc Natl Acad Sci U S A 2016; 113:12809-12814. [PMID: 27791100 DOI: 10.1073/pnas.1608304113] [Citation(s) in RCA: 161] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
There is an important medical need for new antifungal agents with novel mechanisms of action to treat the increasing number of patients with life-threatening systemic fungal disease and to overcome the growing problem of resistance to current therapies. F901318, the leading representative of a novel class of drug, the orotomides, is an antifungal drug in clinical development that demonstrates excellent potency against a broad range of dimorphic and filamentous fungi. In vitro susceptibility testing of F901318 against more than 100 strains from the four main pathogenic Aspergillus spp. revealed minimal inhibitory concentrations of ≤0.06 µg/mL-greater potency than the leading antifungal classes. An investigation into the mechanism of action of F901318 found that it acts via inhibition of the pyrimidine biosynthesis enzyme dihydroorotate dehydrogenase (DHODH) in a fungal-specific manner. Homology modeling of Aspergillus fumigatus DHODH has identified a predicted binding mode of the inhibitor and important interacting amino acid residues. In a murine pulmonary model of aspergillosis, F901318 displays in vivo efficacy against a strain of A. fumigatus sensitive to the azole class of antifungals and a strain displaying an azole-resistant phenotype. F901318 is currently in late Phase 1 clinical trials, offering hope that the antifungal armamentarium can be expanded to include a class of agent with a mechanism of action distinct from currently marketed antifungals.
Collapse
|
18
|
The mechanistic study of Leishmania major dihydro-orotate dehydrogenase based on steady- and pre-steady-state kinetic analysis. Biochem J 2016; 473:651-60. [DOI: 10.1042/bj20150921] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 12/11/2015] [Indexed: 11/17/2022]
Abstract
Leishmania major dihydro-orotate dehydrogenase (DHODHLm) oxidizes dihydro-orotate to orotate (ORO) in the de novo pyrimidine biosynthetic pathway. The enzyme reaction mechanism was elucidated by steady- and pre-steady-state kinetics. ORO release was found to be the rate-limiting step in the overall catalysis.
Collapse
|
19
|
Pery E, Sheehy A, Miranda Nebane N, Misra V, Mankowski MK, Rasmussen L, Lucile White E, Ptak RG, Gabuzda D. Redoxal, an inhibitor of de novo pyrimidine biosynthesis, augments APOBEC3G antiviral activity against human immunodeficiency virus type 1. Virology 2015; 484:276-287. [PMID: 26141568 DOI: 10.1016/j.virol.2015.06.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 05/05/2015] [Accepted: 06/11/2015] [Indexed: 12/31/2022]
Abstract
APOBEC3G (A3G) is a cytidine deaminase that restricts HIV-1 replication by inducing G-to-A hypermutation in viral DNA; deamination-independent mechanisms are also implicated. HIV-1 Vif protein counteracts A3G by inducing its proteasomal degradation. Thus, the Vif-A3G axis is a potential therapeutic target. To identify compounds that inhibit Vif:A3G interaction, a 307,520 compound library was tested in a TR-FRET screen. Two identified compounds, redoxal and lomofungin, inhibited HIV-1 replication in peripheral blood mononuclear cells. Lomofungin activity was linked to A3G, but not pursued further due to cytotoxicity. Redoxal displayed A3G-dependent restriction, inhibiting viral replication by stabilizing A3G protein levels and increasing A3G in virions. A3G-independent activity was also detected. Treatment with uridine or orotate, intermediates of pyrimidine synthesis, diminished redoxal-induced stabilization of A3G and antiviral activity. These results identify redoxal as an inhibitor of HIV-1 replication and suggest its ability to inhibit pyrimidine biosynthesis suppresses viral replication by augmenting A3G antiviral activity.
Collapse
Affiliation(s)
- Erez Pery
- Department of Cancer Immunology and AIDS, Dana Farber Cancer Institute, Boston, MA 02115, United States; Department of Pathology, Harvard Medical School, Boston, MA 02115, United States
| | - Ann Sheehy
- Department of Biology, College of the Holy Cross, Worcester, MA 01610, United States
| | - N Miranda Nebane
- Southern Research Institute High Throughput Screening Center, Birmingham, AL 35205, United States
| | - Vikas Misra
- Department of Cancer Immunology and AIDS, Dana Farber Cancer Institute, Boston, MA 02115, United States
| | - Marie K Mankowski
- Southern Research Institute, Department of Infectious Disease Research, Frederick, MD 21701, United States
| | - Lynn Rasmussen
- Southern Research Institute High Throughput Screening Center, Birmingham, AL 35205, United States
| | - E Lucile White
- Southern Research Institute High Throughput Screening Center, Birmingham, AL 35205, United States
| | - Roger G Ptak
- Southern Research Institute, Department of Infectious Disease Research, Frederick, MD 21701, United States
| | - Dana Gabuzda
- Department of Cancer Immunology and AIDS, Dana Farber Cancer Institute, Boston, MA 02115, United States; Department of Neurology (Microbiology), Harvard Medical School, Boston, MA 02115, United States.
| |
Collapse
|
20
|
Identification of dihydroorotate dehydrogenase as a relevant drug target for 1-hydroxyquinolones in Toxoplasma gondii. Mol Biochem Parasitol 2013; 190:6-15. [DOI: 10.1016/j.molbiopara.2013.05.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Revised: 05/28/2013] [Accepted: 05/28/2013] [Indexed: 11/20/2022]
|
21
|
Munier-Lehmann H, Vidalain PO, Tangy F, Janin YL. On dihydroorotate dehydrogenases and their inhibitors and uses. J Med Chem 2013; 56:3148-67. [PMID: 23452331 DOI: 10.1021/jm301848w] [Citation(s) in RCA: 151] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Proper nucleosides availability is crucial for the proliferation of living entities (eukaryotic cells, parasites, bacteria, and virus). Accordingly, the uses of inhibitors of the de novo nucleosides biosynthetic pathways have been investigated in the past. In the following we have focused on dihydroorotate dehydrogenase (DHODH), the fourth enzyme in the de novo pyrimidine nucleosides biosynthetic pathway. We first described the different types of enzyme in terms of sequence, structure, and biochemistry, including the reported bioassays. In a second part, the series of inhibitors of this enzyme along with a description of their potential or actual uses were reviewed. These inhibitors are indeed used in medicine to treat autoimmune diseases such as rheumatoid arthritis or multiple sclerosis (leflunomide and teriflunomide) and have been investigated in treatments of cancer, virus, and parasite infections (i.e., malaria) as well as in crop science.
Collapse
Affiliation(s)
- Hélène Munier-Lehmann
- Institut Pasteur, Unité de Chimie et Biocatalyse, Département de Biologie Structurale et Chimie, 28 Rue du Dr. Roux, 75724 Paris Cedex 15, France
| | | | | | | |
Collapse
|
22
|
Cordeiro AT, Feliciano PR, Pinheiro MP, Nonato MC. Crystal structure of dihydroorotate dehydrogenase from Leishmania major. Biochimie 2012; 94:1739-48. [DOI: 10.1016/j.biochi.2012.04.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Accepted: 04/03/2012] [Indexed: 01/09/2023]
|
23
|
Hortua Triana MA, Huynh MH, Garavito MF, Fox BA, Bzik DJ, Carruthers VB, Löffler M, Zimmermann BH. Biochemical and molecular characterization of the pyrimidine biosynthetic enzyme dihydroorotate dehydrogenase from Toxoplasma gondii. Mol Biochem Parasitol 2012; 184:71-81. [PMID: 22580100 DOI: 10.1016/j.molbiopara.2012.04.009] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Revised: 04/20/2012] [Accepted: 04/23/2012] [Indexed: 01/27/2023]
Abstract
The pyrimidine biosynthesis pathway in the protozoan pathogen Toxoplasma gondii is essential for parasite growth during infection. To investigate the properties of dihydroorotate dehydrogenase (TgDHOD), the fourth enzyme in the T. gondii pyrimidine pathway, we expressed and purified recombinant TgDHOD. TgDHOD exhibited a specific activity of 84U/mg, a k(cat) of 89s(-1), a K(m)=60μM for l-dihydroorotate, and a K(m)=29μM for decylubiquinone (Q(D)). Quinones lacking or having short isoprenoid side chains yielded lower k(cat)s than Q(D). As expected, fumarate was a poor electron acceptor for this family 2 DHOD. The IC(50)s determined for A77-1726, the active derivative of the human DHOD inhibitor leflunomide, and related compounds MD249 and MD209 were, 91μM, 96μM, and 60μM, respectively. The enzyme was not significantly affected by brequinar or TTFA, known inhibitors of human DHOD, or by atovaquone. DSM190, a known inhibitor of Plasmodium falciparum DHOD, was a poor inhibitor of TgDHOD. TgDHOD exhibits a lengthy 157-residue N-terminal extension, consistent with a potential organellar targeting signal. We constructed C-terminally c-myc tagged TgDHODs to examine subcellular localization of TgDHOD in transgenic parasites expressing the tagged protein. Using both exogenous and endogenous expression strategies, anti-myc fluorescence signal colocalized with antibodies against the mitochondrial marker ATPase. These findings demonstrate that TgDHOD is associated with the parasite's mitochondrion, revealing this organelle as the site of orotate production in T. gondii. The TgDHOD gene appears to be essential because while gene tagging was successful at the TgDHOD gene locus, attempts to delete the TgDHOD gene were not successful in the KU80 background. Collectively, our study suggests that TgDHOD is an excellent target for the development of anti-Toxoplasma drugs.
Collapse
|
24
|
Swerdlow RH. Does mitochondrial DNA play a role in Parkinson's disease? A review of cybrid and other supportive evidence. Antioxid Redox Signal 2012; 16:950-64. [PMID: 21338319 PMCID: PMC3643260 DOI: 10.1089/ars.2011.3948] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
SIGNIFICANCE Mitochondria are currently believed to play an important role in the neurodysfunction and neurodegeneration that underlie Parkinson's disease (PD). RECENT ADVANCES While it increasingly appears that mitochondrial dysfunction in PD can have different causes, it has been proposed that mitochondrial DNA (mtDNA) may account for or drive mitochondrial dysfunction in the majority of the cases. If correct, the responsible mtDNA signatures could represent acquired mutations, inherited mutations, or population-distributed polymorphisms. CRITICAL ISSUES AND FUTURE DIRECTIONS This review discusses the case for mtDNA as a key mediator of PD, and especially focuses on data from studies of PD cytoplasmic hybrid (cybrid) cell lines.
Collapse
Affiliation(s)
- Russell H Swerdlow
- Departments of Neurology, Biochemistry and Molecular Biology, and Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas, USA.
| |
Collapse
|
25
|
Zameitat E, Pierik AJ, Zocher K, Löffler M. Dihydroorotate dehydrogenase from Saccharomyces cerevisiae: spectroscopic investigations with the recombinant enzyme throw light on catalytic properties and metabolism of fumarate analogues. FEMS Yeast Res 2007; 7:897-904. [PMID: 17617217 DOI: 10.1111/j.1567-1364.2007.00275.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
In all organisms the fourth catalytic step of the pyrimidine biosynthesis is driven by the flavoenzyme dihydroorotate dehydrogenase (DHODH, EC 1.3.99.11). Cytosolic DHODH of the established model organism Saccharomyces cerevisiae catalyses the oxidation of dihydroorotate to orotate and the reduction of fumarate to succinate. Here, we investigate the structure and mechanism of DHODH from S. cerevisiae and show that the recombinant ScDHODH exists as a homodimeric enzyme in vitro. Inhibition of ScDHODH by the reaction product was observed and kinetic studies disclosed affinity for orotate (K(ic)=7.7 microM; K(ic) is the competitive inhibition constant). The binding constant for orotate was measured through comparison of UV-visible spectra of the bound and unbound recombinant enzyme. The midpoint reduction potential of DHODH-bound flavine mononucleotide determined from analysis of spectral changes was -242 mV (vs. NHE) under anaerobic conditions. A search for alternative electron acceptors revealed that homologues such as mesaconate can be used as electron acceptors.
Collapse
Affiliation(s)
- Elke Zameitat
- Institute of Physiological Chemistry, Philipps-University Marburg, Marburg, Germany
| | | | | | | |
Collapse
|
26
|
Zameitat E, Freymark G, Dietz CD, Löffler M, Bölker M. Functional expression of human dihydroorotate dehydrogenase (DHODH) in pyr4 mutants of ustilago maydis allows target validation of DHODH inhibitors in vivo. Appl Environ Microbiol 2007; 73:3371-9. [PMID: 17369345 PMCID: PMC1907109 DOI: 10.1128/aem.02569-06] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Dihydroorotate dehydrogenase (DHODH; EC 1.3.99.11) is a central enzyme of pyrimidine biosynthesis and catalyzes the oxidation of dihydroorotate to orotate. DHODH is an important target for antiparasitic and cytostatic drugs since rapid cell proliferation often depends on the de novo synthesis of pyrimidine nucleotides. We have cloned the pyr4 gene encoding mitochondrial DHODH from the basidiomycetous plant pathogen Ustilago maydis. We were able to show that pyr4 contains a functional mitochondrial targeting signal. The deletion of pyr4 resulted in uracil auxotrophy, enhanced sensitivity to UV irradiation, and a loss of pathogenicity on corn plants. The biochemical characterization of purified U. maydis DHODH overproduced in Escherichia coli revealed that the U. maydis enzyme uses quinone electron acceptor Q6 and is resistant to several commonly used DHODH inhibitors. Here we show that the expression of the human DHODH gene fused to the U. maydis mitochondrial targeting signal is able to complement the auxotrophic phenotype of pyr4 mutants. While U. maydis wild-type cells were resistant to the DHODH inhibitor brequinar, strains expressing the human DHODH gene became sensitive to this cytostatic drug. Such engineered U. maydis strains can be used in sensitive in vivo assays for the development of novel drugs specifically targeted at either human or fungal DHODH.
Collapse
Affiliation(s)
- Elke Zameitat
- Faculty of Medicine, Department of Biology, Philipps University Marburg, Karl-von-Frisch-Str. 8, D-35032 Marburg, Germany
| | | | | | | | | |
Collapse
|
27
|
Current awareness on yeast. Yeast 2007. [DOI: 10.1002/yea.1323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|