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Verhoef JM, Boshoven C, Evers F, Akkerman LJ, Gijsbrechts BC, van de Vegte-Bolmer M, van Gemert GJ, Vaidya AB, Kooij TW. Detailing organelle division and segregation in Plasmodium falciparum. bioRxiv 2024:2024.01.30.577899. [PMID: 38352445 PMCID: PMC10862848 DOI: 10.1101/2024.01.30.577899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
The malaria causing parasite, P. falciparum, replicates through a tightly orchestrated process termed schizogony, where approximately 32 daughter parasites are formed in a single infected red blood cell and thousands of daughter cells in mosquito- or liver-stages. One-per-cell organelles, such as the mitochondrion and apicoplast, need to be properly divided and segregated to ensure a complete set of organelles per daughter parasites. Although this is highly essential, details about the processes and mechanisms involved remain unknown. We developed a new reporter parasite line that allows visualization of the mitochondrion in blood- and mosquito stages. Using high-resolution 3D-imaging, we found that the mitochondrion orients in a cartwheel structure, prior to stepwise, non-geometric division during the last stage of schizogony. Analysis of focused ion beam scanning electron microscopy (FIB-SEM) data confirmed these mitochondrial division stages. Furthermore, these data allowed us to elucidate apicoplast division steps, highlighted its close association with the mitochondrion, and showed putative roles of the centriolar plaques (CPs) in apicoplast segregation. These observations form the foundation for a new detailed model of mitochondrial and apicoplast division and segregation during P. falciparum schizogony and pave the way for future studies into the mechanisms of organelle division and segregation.
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Affiliation(s)
- Julie M.J. Verhoef
- Department of Medical Microbiology, Radboudumc Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Cas Boshoven
- Department of Medical Microbiology, Radboudumc Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Felix Evers
- Department of Medical Microbiology, Radboudumc Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Laura J. Akkerman
- Department of Medical Microbiology, Radboudumc Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Barend C.A. Gijsbrechts
- Department of Medical Microbiology, Radboudumc Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Marga van de Vegte-Bolmer
- Department of Medical Microbiology, Radboudumc Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Geert-Jan van Gemert
- Department of Medical Microbiology, Radboudumc Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Akhil B. Vaidya
- Center for Molecular Parasitology, Institute for Molecular Medicine and Infectious Disease, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, USA
| | - Taco W.A. Kooij
- Department of Medical Microbiology, Radboudumc Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, The Netherlands
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Lamb IM, Okoye IC, Mather MW, Vaidya AB. Unique Properties of Apicomplexan Mitochondria. Annu Rev Microbiol 2023; 77:541-560. [PMID: 37406344 DOI: 10.1146/annurev-micro-032421-120540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/07/2023]
Abstract
Apicomplexan parasites constitute more than 6,000 species infecting a wide range of hosts. These include important pathogens such as those causing malaria and toxoplasmosis. Their evolutionary emergence coincided with the dawn of animals. Mitochondrial genomes of apicomplexan parasites have undergone dramatic reduction in their coding capacity, with genes for only three proteins and ribosomal RNA genes present in scrambled fragments originating from both strands. Different branches of the apicomplexans have undergone rearrangements of these genes, with Toxoplasma having massive variations in gene arrangements spread over multiple copies. The vast evolutionary distance between the parasite and the host mitochondria has been exploited for the development of antiparasitic drugs, especially those used to treat malaria, wherein inhibition of the parasite mitochondrial respiratory chain is selectively targeted with little toxicity to the host mitochondria. We describe additional unique characteristics of the parasite mitochondria that are being investigated and provide greater insights into these deep-branching eukaryotic pathogens.
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Affiliation(s)
- Ian M Lamb
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA;
| | - Ijeoma C Okoye
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA;
| | - Michael W Mather
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA;
| | - Akhil B Vaidya
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA;
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Vaidya AB. Inducing indigestion in malaria parasites: Genetic manipulations of a proton pump. Proc Natl Acad Sci U S A 2023; 120:e2310870120. [PMID: 37556486 PMCID: PMC10450399 DOI: 10.1073/pnas.2310870120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/11/2023] Open
Affiliation(s)
- Akhil B. Vaidya
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA19129
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Tewari SG, Elahi R, Kwan B, Rajaram K, Bhatnagar S, Reifman J, Prigge ST, Vaidya AB, Wallqvist A. Metabolic responses in blood-stage malaria parasites associated with increased and decreased sensitivity to PfATP4 inhibitors. Malar J 2023; 22:56. [PMID: 36788578 PMCID: PMC9930341 DOI: 10.1186/s12936-023-04481-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 02/03/2023] [Indexed: 02/16/2023] Open
Abstract
BACKGROUND Spiroindolone and pyrazoleamide antimalarial compounds target Plasmodium falciparum P-type ATPase (PfATP4) and induce disruption of intracellular Na+ homeostasis. Recently, a PfATP4 mutation was discovered that confers resistance to a pyrazoleamide while increasing sensitivity to a spiroindolone. Transcriptomic and metabolic adaptations that underlie this seemingly contradictory response of P. falciparum to sublethal concentrations of each compound were examined to understand the different cellular accommodation to PfATP4 disruptions. METHODS A genetically engineered P. falciparum Dd2 strain (Dd2A211V) carrying an Ala211Val (A211V) mutation in PfATP4 was used to identify metabolic adaptations associated with the mutation that results in decreased sensitivity to PA21A092 (a pyrazoleamide) and increased sensitivity to KAE609 (a spiroindolone). First, sublethal doses of PA21A092 and KAE609 causing substantial reduction (30-70%) in Dd2A211V parasite replication were identified. Then, at this sublethal dose of PA21A092 (or KAE609), metabolomic and transcriptomic data were collected during the first intraerythrocytic developmental cycle. Finally, the time-resolved data were integrated with a whole-genome metabolic network model of P. falciparum to characterize antimalarial-induced physiological adaptations. RESULTS Sublethal treatment with PA21A092 caused significant (p < 0.001) alterations in the abundances of 91 Plasmodium gene transcripts, whereas only 21 transcripts were significantly altered due to sublethal treatment with KAE609. In the metabolomic data, a substantial alteration (≥ fourfold) in the abundances of carbohydrate metabolites in the presence of either compound was found. The estimated rates of macromolecule syntheses between the two antimalarial-treated conditions were also comparable, except for the rate of lipid synthesis. A closer examination of parasite metabolism in the presence of either compound indicated statistically significant differences in enzymatic activities associated with synthesis of phosphatidylcholine, phosphatidylserine, and phosphatidylinositol. CONCLUSION The results of this study suggest that malaria parasites activate protein kinases via phospholipid-dependent signalling in response to the ionic perturbation induced by the Na+ homeostasis disruptor PA21A092. Therefore, targeted disruption of phospholipid signalling in PA21A092-resistant parasites could be a means to block the emergence of resistance to PA21A092.
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Affiliation(s)
- Shivendra G Tewari
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Development Command, Fort Detrick, MD, USA. .,The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, USA.
| | - Rubayet Elahi
- Department of Molecular Microbiology and Immunology, Johns Hopkins University, Baltimore, MD, USA
| | - Bobby Kwan
- Department of Molecular Microbiology and Immunology, Johns Hopkins University, Baltimore, MD, USA
| | - Krithika Rajaram
- Department of Molecular Microbiology and Immunology, Johns Hopkins University, Baltimore, MD, USA
| | - Suyash Bhatnagar
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, USA.,Office of Vaccines Research and Review, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, USA
| | - Jaques Reifman
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Development Command, Fort Detrick, MD, USA
| | - Sean T Prigge
- Department of Molecular Microbiology and Immunology, Johns Hopkins University, Baltimore, MD, USA
| | - Akhil B Vaidya
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Anders Wallqvist
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Development Command, Fort Detrick, MD, USA.
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Dass S, Mather MW, Morrisey JM, Ling L, Vaidya AB, Ke H. Transcriptional changes in Plasmodium falciparum upon conditional knock down of mitochondrial ribosomal proteins RSM22 and L23. PLoS One 2022; 17:e0274993. [PMID: 36201550 PMCID: PMC9536634 DOI: 10.1371/journal.pone.0274993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 09/07/2022] [Indexed: 11/23/2022] Open
Abstract
The mitochondrion of malaria parasites is an attractive antimalarial drug target, which require mitoribosomes to translate genes encoded in the mitochondrial (mt) DNA. Plasmodium mitoribosomes are composed of highly fragmented ribosomal RNA (rRNA) encoded in the mtDNA. All mitoribosomal proteins (MRPs) and other assembly factors are encoded in the nuclear genome. Here, we have studied one putative assembly factor, RSM22 (Pf3D7_1027200) and one large subunit (LSU) MRP, L23 (Pf3D7_1239100) in Plasmodium falciparum. We show that both proteins localize to the mitochondrion. Conditional knock down (KD) of PfRSM22 or PfMRPL23 leads to reduced cytochrome bc1 complex activity and increased sensitivity to bc1 inhibitors such as atovaquone and ELQ-300. Using RNA sequencing as a tool, we reveal the transcriptomic changes of nuclear and mitochondrial genomes upon KD of these two proteins. In the early phase of KD, while most mt rRNAs and transcripts of putative MRPs were downregulated in the absence of PfRSM22, many mt rRNAs and several MRPs were upregulated after KD of PfMRPL23. The contrast effects in the early phase of KD likely suggests non-redundant roles of PfRSM22 and PfMRPL23 in the assembly of P. falciparum mitoribosomes. At the late time points of KD, loss of PfRSM22 and PfMRPL23 caused defects in many essential metabolic pathways and transcripts related to essential mitochondrial functions, leading to parasite death. In addition, we enlist mitochondrial proteins of unknown function that are likely novel Plasmodium MRPs based on their structural similarity to known MRPs as well as their expression profiles in KD parasites.
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Affiliation(s)
- Swati Dass
- Center for Molecular Parasitology, Department of Microbiology and Immunology Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Michael W. Mather
- Center for Molecular Parasitology, Department of Microbiology and Immunology Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Joanne M. Morrisey
- Center for Molecular Parasitology, Department of Microbiology and Immunology Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Liqin Ling
- Center for Molecular Parasitology, Department of Microbiology and Immunology Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Akhil B. Vaidya
- Center for Molecular Parasitology, Department of Microbiology and Immunology Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Hangjun Ke
- Center for Molecular Parasitology, Department of Microbiology and Immunology Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
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Lamb IM, Rios KT, Shukla A, Ahiya AI, Morrisey J, Mell JC, Lindner SE, Mather MW, Vaidya AB. Mitochondrially targeted proximity biotinylation and proteomic analysis in Plasmodium falciparum. PLoS One 2022; 17:e0273357. [PMID: 35984838 PMCID: PMC9390924 DOI: 10.1371/journal.pone.0273357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 08/08/2022] [Indexed: 01/26/2023] Open
Abstract
Despite ongoing efforts to control malaria infection, progress in lowering the number of deaths and infections appears to have stalled. The continued high incidence of malaria infection and mortality is in part due to emergence of parasites resistant to frontline antimalarials. This highlights the need for continued identification of novel protein drug targets. Mitochondrial functions in Plasmodium falciparum, the deadliest species of human malaria parasite, are targets of validated antimalarials including atovaquone and proguanil (Malarone). Thus, there has been great interest in identifying other essential mitochondrial proteins as candidates for novel drug targets. Garnering an increased understanding of the proteomic landscape inside the P. falciparum mitochondrion will also allow us to learn about the basic biology housed within this unique organelle. We employed a proximity biotinylation technique and mass spectrometry to identify novel P. falciparum proteins putatively targeted to the mitochondrion. We fused the leader sequence of a mitochondrially targeted chaperone, Hsp60, to the promiscuous biotin ligase TurboID. Through these experiments, we generated a list of 122 "putative mitochondrial" proteins. To verify whether these proteins were indeed mitochondrial, we chose five candidate proteins of interest for localization studies using ectopic expression and tagging of each full-length protein. This allowed us to localize four candidate proteins of unknown function to the mitochondrion, three of which have previously been assessed to be essential. We suggest that phenotypic characterization of these and other proteins from this list of 122 could be fruitful in understanding the basic mitochondrial biology of these parasites and aid antimalarial drug discovery efforts.
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Affiliation(s)
- Ian M. Lamb
- Center for Molecular Parasitology, Institute for Molecular Medicine and Infectious Disease, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, United States of America
| | - Kelly T. Rios
- Department of Biochemistry and Molecular Biology, The Huck Center for Malaria Research, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Anurag Shukla
- Center for Molecular Parasitology, Institute for Molecular Medicine and Infectious Disease, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, United States of America
| | - Avantika I. Ahiya
- Center for Molecular Parasitology, Institute for Molecular Medicine and Infectious Disease, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, United States of America
| | - Joanne Morrisey
- Center for Molecular Parasitology, Institute for Molecular Medicine and Infectious Disease, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, United States of America
| | - Joshua C. Mell
- Center for Molecular Parasitology, Institute for Molecular Medicine and Infectious Disease, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, United States of America
| | - Scott E. Lindner
- Department of Biochemistry and Molecular Biology, The Huck Center for Malaria Research, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Michael W. Mather
- Center for Molecular Parasitology, Institute for Molecular Medicine and Infectious Disease, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, United States of America
| | - Akhil B. Vaidya
- Center for Molecular Parasitology, Institute for Molecular Medicine and Infectious Disease, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, United States of America
- * E-mail:
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7
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Tewari SG, Kwan B, Elahi R, Rajaram K, Reifman J, Prigge ST, Vaidya AB, Wallqvist A. Metabolic adjustments of blood-stage Plasmodium falciparum in response to sublethal pyrazoleamide exposure. Sci Rep 2022; 12:1167. [PMID: 35064153 PMCID: PMC8782945 DOI: 10.1038/s41598-022-04985-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 01/04/2022] [Indexed: 11/08/2022] Open
Abstract
Due to the recurring loss of antimalarial drugs to resistance, there is a need for novel targets, drugs, and combination therapies to ensure the availability of current and future countermeasures. Pyrazoleamides belong to a novel class of antimalarial drugs that disrupt sodium ion homeostasis, although the exact consequences of this disruption in Plasmodium falciparum remain under investigation. In vitro experiments demonstrated that parasites carrying mutations in the metabolic enzyme PfATP4 develop resistance to pyrazoleamide compounds. However, the underlying mechanisms that allow mutant parasites to evade pyrazoleamide treatment are unclear. Here, we first performed experiments to identify the sublethal dose of a pyrazoleamide compound (PA21A092) that caused a significant reduction in growth over one intraerythrocytic developmental cycle (IDC). At this drug concentration, we collected transcriptomic and metabolomic data at multiple time points during the IDC to quantify gene- and metabolite-level alterations in the treated parasites. To probe the effects of pyrazoleamide treatment on parasite metabolism, we coupled the time-resolved omics data with a metabolic network model of P. falciparum. We found that the drug-treated parasites adjusted carbohydrate metabolism to enhance synthesis of myoinositol-a precursor for phosphatidylinositol biosynthesis. This metabolic adaptation caused a decrease in metabolite flux through the pentose phosphate pathway, causing a decreased rate of RNA synthesis and an increase in oxidative stress. Our model analyses suggest that downstream consequences of enhanced myoinositol synthesis may underlie adjustments that could lead to resistance emergence in P. falciparum exposed to a sublethal dose of a pyrazoleamide drug.
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Affiliation(s)
- Shivendra G Tewari
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Development Command, Fort Detrick, MD, USA.
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, USA.
| | - Bobby Kwan
- Department of Molecular Microbiology and Immunology, Johns Hopkins University, Baltimore, MD, USA
| | - Rubayet Elahi
- Department of Molecular Microbiology and Immunology, Johns Hopkins University, Baltimore, MD, USA
| | - Krithika Rajaram
- Department of Molecular Microbiology and Immunology, Johns Hopkins University, Baltimore, MD, USA
| | - Jaques Reifman
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Development Command, Fort Detrick, MD, USA
| | - Sean T Prigge
- Department of Molecular Microbiology and Immunology, Johns Hopkins University, Baltimore, MD, USA
| | - Akhil B Vaidya
- Department of Microbiology and Immunology, Center for Molecular Parasitology, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Anders Wallqvist
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Development Command, Fort Detrick, MD, USA.
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Kreutzfeld O, Rasmussen SA, Ramanathan AA, Tumwebaze PK, Byaruhanga O, Katairo T, Asua V, Okitwi M, Orena S, Legac J, Conrad MD, Nsobya SL, Aydemir O, Bailey J, Duffey M, Bayles BR, Vaidya AB, Cooper RA, Rosenthal PJ. Associations between Varied Susceptibilities to PfATP4 Inhibitors and Genotypes in Ugandan Plasmodium falciparum Isolates. Antimicrob Agents Chemother 2021; 65:e0077121. [PMID: 34339273 PMCID: PMC8448140 DOI: 10.1128/aac.00771-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 07/22/2021] [Indexed: 11/20/2022] Open
Abstract
Among novel compounds under recent investigation as potential new antimalarial drugs are three independently developed inhibitors of the Plasmodium falciparum P-type ATPase (PfATP4): KAE609 (cipargamin), PA92, and SJ733. We assessed ex vivo susceptibilities to these compounds of 374 fresh P. falciparum isolates collected in Tororo and Busia districts, Uganda, from 2016 to 2019. Median IC50s were 65 nM for SJ733, 9.1 nM for PA92, and 0.5 nM for KAE609. Sequencing of pfatp4 for 218 of these isolates demonstrated many nonsynonymous single nucleotide polymorphisms; the most frequent mutations were G1128R (69% of isolates mixed or mutant), Q1081K/R (68%), G223S (25%), N1045K (16%), and D1116G/N/Y (16%). The G223S mutation was associated with decreased susceptibility to SJ733, PA92, and KAE609. The D1116G/N/Y mutations were associated with decreased susceptibility to SJ733, and the presence of mutations at both codons 223 and 1116 was associated with decreased susceptibility to PA92 and SJ733. In all of these cases, absolute differences in susceptibilities of wild-type (WT) and mutant parasites were modest. Analysis of clones separated from mixed field isolates consistently identified mutant clones as less susceptible than WT. Analysis of isolates from other sites demonstrated the presence of the G223S and D1116G/N/Y mutations across Uganda. Our results indicate that malaria parasites circulating in Uganda have a number of polymorphisms in PfATP4 and that modestly decreased susceptibility to PfATP4 inhibitors is associated with some mutations now present in Ugandan parasites.
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Affiliation(s)
- Oriana Kreutzfeld
- Department of Medicine, University of California, San Francisco, California, USA
| | | | - Aarti A. Ramanathan
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | | | | | - Thomas Katairo
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Victor Asua
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Martin Okitwi
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Stephen Orena
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Jennifer Legac
- Department of Medicine, University of California, San Francisco, California, USA
| | - Melissa D. Conrad
- Department of Medicine, University of California, San Francisco, California, USA
| | | | | | | | | | - Brett R. Bayles
- Dominican University of California, San Rafael, California, USA
| | - Akhil B. Vaidya
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | | | - Philip J. Rosenthal
- Department of Medicine, University of California, San Francisco, California, USA
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Bhatnagar S, Nicklas S, Morrisey JM, Goldberg DE, Vaidya AB. Diverse Chemical Compounds Target Plasmodium falciparum Plasma Membrane Lipid Homeostasis. ACS Infect Dis 2019; 5:550-558. [PMID: 30638365 DOI: 10.1021/acsinfecdis.8b00277] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Lipid homeostasis is essential to the maintenance of life. We previously reported that disruptions of the parasite Na+ homeostasis via inhibition of PfATP4 resulted in elevated cholesterol within the parasite plasma membrane as assessed by saponin sensitivity. A large number of compounds have been shown to target the parasite Na+ homeostasis. We screened 800 compounds from the Malaria and Pathogen Boxes to identify chemotypes that disrupted the parasite plasma membrane lipid homeostasis. Here, we show that the compounds disrupting parasite Na+ homeostasis also induced saponin sensitivity, an indication of parasite lipid homeostasis disruption. Remarkably, 13 compounds were identified that altered the plasma membrane lipid composition independently of the Na+ homeostasis disruption. Further studies suggest that these compounds target the Plasmodium falciparum Niemann-Pick type C1-related (PfNCR1) protein, which is hypothesized to be involved in maintaining plasma membrane lipid composition. PfNCR1, like PfATP4, appears to be targeted by multiple chemotypes with the potential for drug discovery.
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Affiliation(s)
- Suyash Bhatnagar
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, Pennsylvania 19129, United States of America
| | - Sezin Nicklas
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, Pennsylvania 19129, United States of America
| | - Joanne M. Morrisey
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, Pennsylvania 19129, United States of America
| | - Daniel E. Goldberg
- Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, 4990 Children’s Place, St. Louis, Missouri 63110, United States of America
| | - Akhil B. Vaidya
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, Pennsylvania 19129, United States of America
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Ke H, Ganesan SM, Dass S, Morrisey JM, Pou S, Nilsen A, Riscoe MK, Mather MW, Vaidya AB. Mitochondrial type II NADH dehydrogenase of Plasmodium falciparum (PfNDH2) is dispensable in the asexual blood stages. PLoS One 2019; 14:e0214023. [PMID: 30964863 PMCID: PMC6456166 DOI: 10.1371/journal.pone.0214023] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Accepted: 03/05/2019] [Indexed: 11/23/2022] Open
Abstract
The battle against malaria has been substantially impeded by the recurrence of drug resistance in Plasmodium falciparum, the deadliest human malaria parasite. To counter the problem, novel antimalarial drugs are urgently needed, especially those that target unique pathways of the parasite, since they are less likely to have side effects. The mitochondrial type II NADH dehydrogenase (NDH2) of P. falciparum, PfNDH2 (PF3D7_0915000), has been considered a good prospective antimalarial drug target for over a decade, since malaria parasites lack the conventional multi-subunit NADH dehydrogenase, or Complex I, present in the mammalian mitochondrial electron transport chain (mtETC). Instead, Plasmodium parasites contain a single subunit NDH2, which lacks proton pumping activity and is absent in humans. A significant amount of effort has been expended to develop PfNDH2 specific inhibitors, yet the essentiality of PfNDH2 has not been convincingly verified. Herein, we knocked out PfNDH2 in P. falciparum via a CRISPR/Cas9 mediated approach. Deletion of PfNDH2 does not alter the parasite’s susceptibility to multiple mtETC inhibitors, including atovaquone and ELQ-300. We also show that the antimalarial activity of the fungal NDH2 inhibitor HDQ and its new derivative CK-2-68 is due to inhibition of the parasite cytochrome bc1 complex rather than PfNDH2. These compounds directly inhibit the ubiquinol-cytochrome c reductase activity of the malarial bc1 complex. Our results suggest that PfNDH2 is not likely a good antimalarial drug target.
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Affiliation(s)
- Hangjun Ke
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
- * E-mail:
| | - Suresh M. Ganesan
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Swati Dass
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Joanne M. Morrisey
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Sovitj Pou
- Portland VA Medical Center, Portland, Oregon, United States of America
| | - Aaron Nilsen
- Portland VA Medical Center, Portland, Oregon, United States of America
| | - Michael K. Riscoe
- Portland VA Medical Center, Portland, Oregon, United States of America
| | - Michael W. Mather
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Akhil B. Vaidya
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
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11
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Istvan ES, Das S, Bhatnagar S, Beck JR, Owen E, Llinas M, Ganesan SM, Niles JC, Winzeler E, Vaidya AB, Goldberg DE. Plasmodium Niemann-Pick type C1-related protein is a druggable target required for parasite membrane homeostasis. eLife 2019; 8:40529. [PMID: 30888318 PMCID: PMC6424564 DOI: 10.7554/elife.40529] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 02/05/2019] [Indexed: 01/05/2023] Open
Abstract
Plasmodium parasites possess a protein with homology to Niemann-Pick Type C1 proteins (Niemann-Pick Type C1-Related protein, NCR1). We isolated parasites with resistance-conferring mutations in Plasmodium falciparum NCR1 (PfNCR1) during selections with three diverse small-molecule antimalarial compounds and show that the mutations are causative for compound resistance. PfNCR1 protein knockdown results in severely attenuated growth and confers hypersensitivity to the compounds. Compound treatment or protein knockdown leads to increased sensitivity of the parasite plasma membrane (PPM) to the amphipathic glycoside saponin and engenders digestive vacuoles (DVs) that are small and malformed. Immuno-electron microscopy and split-GFP experiments localize PfNCR1 to the PPM. Our experiments show that PfNCR1 activity is critically important for the composition of the PPM and is required for DV biogenesis, suggesting PfNCR1 as a novel antimalarial drug target. Editorial note: This article has been through an editorial process in which the authors decide how to respond to the issues raised during peer review. The Reviewing Editor's assessment is that all the issues have been addressed (see decision letter).
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Affiliation(s)
- Eva S Istvan
- Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, Saint Louis, United States.,Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, United States
| | - Sudipta Das
- Department of Microbiology and Immunology, Center for Molecular Parasitology, Drexel University College of Medicine, Philadelphia, United States
| | - Suyash Bhatnagar
- Department of Microbiology and Immunology, Center for Molecular Parasitology, Drexel University College of Medicine, Philadelphia, United States
| | - Josh R Beck
- Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, Saint Louis, United States.,Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, United States
| | - Edward Owen
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, United States.,Huck Center for Malaria Research, Pennsylvania State University, University Park, United States.,Department of Chemistry, Pennsylvania State University, University Park, United States
| | - Manuel Llinas
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, United States.,Huck Center for Malaria Research, Pennsylvania State University, University Park, United States.,Department of Chemistry, Pennsylvania State University, University Park, United States
| | - Suresh M Ganesan
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, United States
| | - Jacquin C Niles
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, United States
| | - Elizabeth Winzeler
- Department of Pediatrics, University of California San Diego School of Medicine, La Jolla, United States
| | - Akhil B Vaidya
- Department of Microbiology and Immunology, Center for Molecular Parasitology, Drexel University College of Medicine, Philadelphia, United States
| | - Daniel E Goldberg
- Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, Saint Louis, United States.,Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, United States
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12
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Ke H, Dass S, Morrisey JM, Mather MW, Vaidya AB. The mitochondrial ribosomal protein L13 is critical for the structural and functional integrity of the mitochondrion in Plasmodium falciparum. J Biol Chem 2018; 293:8128-8137. [PMID: 29626096 DOI: 10.1074/jbc.ra118.002552] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 04/02/2018] [Indexed: 12/22/2022] Open
Abstract
The phylum Apicomplexa contains a group of protozoa causing diseases in humans and livestock. Plasmodium spp., the causative agent of malaria, contains a mitochondrion that is very divergent from that of their hosts. The malarial mitochondrion is a clinically validated target for the antimalarial drug atovaquone, which specifically blocks the electron transfer activity of the bc1 complex of the mitochondrial electron transport chain (mtETC). Most mtETC proteins are nuclear-encoded and imported from the cytosol, but three key protein subunits are encoded in the Plasmodium mitochondrial genome: cyt b, COXI, and COXIII. They are translated inside the mitochondrion by mitochondrial ribosomes (mitoribosomes). Here, we characterize the function of one large mitoribosomal protein in Plasmodium falciparum, PfmRPL13. We found that PfmRPL13 localizes to the parasite mitochondrion and is refractory to genetic knockout. Ablation of PfmRPL13 using a conditional knockdown system (TetR-DOZI-aptamer) caused a series of adverse events in the parasite, including mtETC deficiency, loss of mitochondrial membrane potential (Δψm), and death. The PfmRPL13 knockdown parasite also became hypersensitive to proguanil, a drug proposed to target an alternative process for maintaining Δψm Surprisingly, transmission EM revealed that PfmRPL13 disruption also resulted in an unusually elongated and branched mitochondrion. The growth arrest of the knockdown parasite could be rescued with a second copy of PfmRPL13, but not by supplementation with decylubiquinone or addition of a yeast dihydroorotate dehydrogenase gene. In summary, we provide first and direct evidence that mitoribosomes are essential for malaria parasites to maintain the structural and functional integrity of the mitochondrion.
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Affiliation(s)
- Hangjun Ke
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19129.
| | - Swati Dass
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19129
| | - Joanne M Morrisey
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19129
| | - Michael W Mather
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19129
| | - Akhil B Vaidya
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19129
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13
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Frueh L, Li Y, Mather MW, Li Q, Pou S, Nilsen A, Winter RW, Forquer IP, Pershing AM, Xie LH, Smilkstein MJ, Caridha D, Koop DR, Campbell RF, Sciotti RJ, Kreishman-Deitrick M, Kelly JX, Vesely B, Vaidya AB, Riscoe MK. Alkoxycarbonate Ester Prodrugs of Preclinical Drug Candidate ELQ-300 for Prophylaxis and Treatment of Malaria. ACS Infect Dis 2017; 3:728-735. [PMID: 28927276 DOI: 10.1021/acsinfecdis.7b00062] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
ELQ-300 is a preclinical antimalarial drug candidate that is active against liver, blood, and transmission stages of Plasmodium falciparum. While ELQ-300 is highly effective when administered in a low multidose regimen, poor aqueous solubility and high crystallinity have hindered its clinical development. To overcome its challenging physiochemical properties, a number of bioreversible alkoxycarbonate ester prodrugs of ELQ-300 were synthesized. These bioreversible prodrugs are converted to ELQ-300 by host and parasite esterase action in the liver and bloodstream of the host. One such alkoxycarbonate prodrug, ELQ-331, is curative against Plasmodium yoelii with a single low dose of 3 mg/kg in a murine model of patent malaria infection. ELQ-331 is at least as fully protective as ELQ-300 in a murine malaria prophylaxis model when delivered 24 h before sporozoite inoculation at an oral dose of 1 mg/kg. Here, we show that ELQ-331 is a promising prodrug of ELQ-300 with improved physiochemical and metabolic properties and excellent potential for clinical formulation.
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Affiliation(s)
- Lisa Frueh
- Experimental Chemotherapy Laboratory, VA Medical Center (Mail code RD-33), 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, United States
- Department of Molecular Microbiology and
Immunology, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97239, United States
| | - Yuexin Li
- Experimental Chemotherapy Laboratory, VA Medical Center (Mail code RD-33), 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, United States
| | - Michael W. Mather
- Department
of Microbiology and Immunology, Drexel University, 2900 W. Queen Lane, Philadelphia, Pennsylvania 19129, United States
| | - Qigui Li
- Experimental
Therapeutics Branch, Military Malaria Research Program (MMRP), Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, Maryland 20910, United States
| | - Sovitj Pou
- Department of Molecular Microbiology and
Immunology, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97239, United States
| | - Aaron Nilsen
- Experimental Chemotherapy Laboratory, VA Medical Center (Mail code RD-33), 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, United States
| | - Rolf W. Winter
- Experimental Chemotherapy Laboratory, VA Medical Center (Mail code RD-33), 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, United States
| | - Isaac P. Forquer
- Experimental Chemotherapy Laboratory, VA Medical Center (Mail code RD-33), 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, United States
| | - April M. Pershing
- Department
of Microbiology and Immunology, Drexel University, 2900 W. Queen Lane, Philadelphia, Pennsylvania 19129, United States
| | - Lisa H. Xie
- Experimental
Therapeutics Branch, Military Malaria Research Program (MMRP), Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, Maryland 20910, United States
| | - Martin J. Smilkstein
- Experimental Chemotherapy Laboratory, VA Medical Center (Mail code RD-33), 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, United States
| | - Diana Caridha
- Experimental
Therapeutics Branch, Military Malaria Research Program (MMRP), Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, Maryland 20910, United States
| | - Dennis R. Koop
- Department of Physiology and Pharmacology, Oregon Health & Science University, 3181 S.W. Sam Jackson Park Road, Portland, Oregon 97239, United States
| | - Robert F. Campbell
- Experimental
Therapeutics Branch, Military Malaria Research Program (MMRP), Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, Maryland 20910, United States
| | - Richard J. Sciotti
- Experimental
Therapeutics Branch, Military Malaria Research Program (MMRP), Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, Maryland 20910, United States
| | - Mara Kreishman-Deitrick
- Experimental
Therapeutics Branch, Military Malaria Research Program (MMRP), Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, Maryland 20910, United States
| | - Jane X. Kelly
- Experimental Chemotherapy Laboratory, VA Medical Center (Mail code RD-33), 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, United States
| | - Brian Vesely
- Experimental
Therapeutics Branch, Military Malaria Research Program (MMRP), Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, Maryland 20910, United States
| | - Akhil B. Vaidya
- Department
of Microbiology and Immunology, Drexel University, 2900 W. Queen Lane, Philadelphia, Pennsylvania 19129, United States
| | - Michael K. Riscoe
- Experimental Chemotherapy Laboratory, VA Medical Center (Mail code RD-33), 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, United States
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14
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Bushell E, Gomes AR, Sanderson T, Anar B, Girling G, Herd C, Metcalf T, Modrzynska K, Schwach F, Martin RE, Mather MW, McFadden GI, Parts L, Rutledge GG, Vaidya AB, Wengelnik K, Rayner JC, Billker O. Functional Profiling of a Plasmodium Genome Reveals an Abundance of Essential Genes. Cell 2017; 170:260-272.e8. [PMID: 28708996 PMCID: PMC5509546 DOI: 10.1016/j.cell.2017.06.030] [Citation(s) in RCA: 340] [Impact Index Per Article: 48.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 04/13/2017] [Accepted: 06/19/2017] [Indexed: 12/12/2022]
Abstract
The genomes of malaria parasites contain many genes of unknown function. To assist drug development through the identification of essential genes and pathways, we have measured competitive growth rates in mice of 2,578 barcoded Plasmodium berghei knockout mutants, representing >50% of the genome, and created a phenotype database. At a single stage of its complex life cycle, P. berghei requires two-thirds of genes for optimal growth, the highest proportion reported from any organism and a probable consequence of functional optimization necessitated by genomic reductions during the evolution of parasitism. In contrast, extreme functional redundancy has evolved among expanded gene families operating at the parasite-host interface. The level of genetic redundancy in a single-celled organism may thus reflect the degree of environmental variation it experiences. In the case of Plasmodium parasites, this helps rationalize both the relative successes of drugs and the greater difficulty of making an effective vaccine. Two-thirds of Plasmodium berghei genes contribute to normal blood stage growth The core genome of malaria parasites is highly optimized for rapid host colonization Essential parasite genes and pathways are identified for drug target prioritization Low functional redundancy reflects the constant environment encountered by a parasite
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Affiliation(s)
- Ellen Bushell
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, UK
| | - Ana Rita Gomes
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, UK
| | - Theo Sanderson
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, UK
| | - Burcu Anar
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, UK
| | - Gareth Girling
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, UK
| | - Colin Herd
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, UK
| | - Tom Metcalf
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, UK
| | - Katarzyna Modrzynska
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, UK
| | - Frank Schwach
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, UK
| | - Rowena E Martin
- Research School of Biology, Australian National University, Canberra, Australia
| | | | - Geoffrey I McFadden
- School of Biosciences, University of Melbourne, Royal Parade, Parkville, Australia
| | - Leopold Parts
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, UK
| | - Gavin G Rutledge
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, UK
| | - Akhil B Vaidya
- Drexel University College of Medicine, Philadelphia, PA, USA
| | - Kai Wengelnik
- DIMNP, CNRS, INSERM, University Montpellier, Montpellier, France
| | - Julian C Rayner
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, UK.
| | - Oliver Billker
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, UK.
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15
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Paradkar PH, Mishra LS, Joshi JV, Dandekar SP, Vaidya RA, Vaidya AB. In vitro macrophage activation: A technique for screening anti-inflammatory, immunomodulatory and anticancer activity of phytomolecules. Indian J Exp Biol 2017; 55:133-141. [PMID: 30184414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Macrophage activation plays a significant role in homeostasis of organisms. Various internal and external stress factors may affect their function, leading to adverse effects on the body. ‘In vitro macrophage activation techniques provide us with a window to understand the mechanisms of inflammation and response of macrophages to the modulating interventions. Apart from infectious diseases, inflammation is also the major culprit in pathogenesis of many noncommunicable diseases such as arthritis, obesity, metabolic syndrome, diabetes, cancer, cardiovascular disease etc. In vitro macrophage activation allows us to study the role of polarized macrophages in the process of pathogenesis. This emerging technique leads to newer diagnostics, understanding pathophysiological mechanism/s, drug development and management of chronic inflammatory diseases. We, at MRC-KHS, use this technique for screening of medicinal plant-derived phytomolecules for their anti-inflammatory, immunomodulatory and anticancer activities. This review briefly outlines the different experimental models of in vitro macrophage activation and their applications for understanding the pathophysiological mechanisms of underlying chronic inflammation and screening of therapeutic activity of plant-based phytomolecules.
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16
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Jaiswal YS, Tatke PA, Gabhe SY, Vaidya AB. Antidiabetic activity of extracts of Anacardium occidentale Linn. leaves on n-streptozotocin diabetic rats. J Tradit Complement Med 2016; 7:421-427. [PMID: 29034189 PMCID: PMC5634720 DOI: 10.1016/j.jtcme.2016.11.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 11/29/2016] [Indexed: 02/07/2023] Open
Abstract
Anacardium occidentale L. (Anacardiaceae) is used in South Cameroon as well as in other tropical countries by traditional practitioners as a folk remedy for treatment of diabetes mellitus. We demonstrated the antidiabetic potential of the plant extracts in n-streptozotocin diabetic rats. The aim of the current study was to investigate the antidiabetic effects of ethanol extract of leaves of A. occidentale on neonatal streptozotocin diabetic rats. Two day old neonates were injected with 100 mg/kg of streptozotocin. At the end of the experimental period of 30 days, reduction in the fasting blood glucose levels, serum insulin, glycated hemoglobin levels, serum lipid parameters, and renal function biomarkers were estimated in the control and treated rats. Histopathological examination of liver, kidney and pancreas were also carried out. On administration of 100 mg/kg of plant extract, blood glucose levels of the rats showed 8.01% and 19.25% decrease in the fasting blood glucose levels on day 15 and day 30, respectively. The administration of extract showed that the effects of extract treatment are comparable to treatment with the standard drug Pioglitazone. These results demonstrate significant antidiabetic potential of the ethanol extract of leaves of A. occidentale, justifying the use of plant in the indigenous system of medicine. Further studies for investigating the specific compound(s) responsible for such beneficial role in diabetes would open new outlook in the therapy of type 2 diabetes.
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Affiliation(s)
- Y S Jaiswal
- C.U.Shah College of Pharmacy, S.N.D.T Women's University, Mumbai 400049, India
| | - P A Tatke
- C.U.Shah College of Pharmacy, S.N.D.T Women's University, Mumbai 400049, India
| | - S Y Gabhe
- C.U.Shah College of Pharmacy, S.N.D.T Women's University, Mumbai 400049, India
| | - A B Vaidya
- ICMR Advanced Centre of Reverse Pharmacology in Traditional Medicine, Kasturba Health Society, Vile Parle-(W), Mumbai 400 056, India
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17
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Godse CS, Tathed PS, Talwalkar SS, Vaidya RA, Amonkar AJ, Vaidya AB, Vaidya ADB. Antiparasitic and disease-modifying activity of Nyctanthes arbor-tristis Linn. in malaria: An exploratory clinical study. J Ayurveda Integr Med 2016; 7:238-248. [PMID: 27914754 PMCID: PMC5192257 DOI: 10.1016/j.jaim.2016.08.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 08/04/2016] [Accepted: 08/06/2016] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND An unceasing threat of drug resistance continuously poses demand for new antimalarial drugs. A scientific assessment of traditionally used antimalarial plants through reverse pharmacology is crucial for a fast track drug discovery. An Ayurvedic plant Nyctanthes arbor-tristis Linn. - (Parijat) is being used in clinical practice and had shown antimalarial activity, with a parasite clearance in 76.6% of 120 patients, in an earlier clinical study. OBJECTIVE To further explore antimalarial potential of the plant through additional objective markers. MATERIALS AND METHODS An open-labelled observational study was conducted at M.A. Podar Hospital - Ayurveda (MAPH-A) after ethics committee approval. Administration of a paste of 5 fresh leaves, thrice a day for a week was a standard practice for management of malaria at MAPH-A. Clinical activity of N. arbor-tristis was evaluated by monitoring pyrexia, parasitemia and morbidity score (MS) in twenty patients. In addition, immune and biochemical markers and organ functions were monitored for objective markers of response. Student's paired-'t' test was applied to assess statistical significance. RESULTS Ten out of 20 patients showed both fever and parasite clearance, which was confirmed by polymerase chain reaction. Remaining ten patients had persistent but decreasing parasitemia. Four of them needed chloroquine as a fail-safe procedure. Irrespective of the degree of parasitemia all the patients showed decrease in MS. There was also an increase in platelet count and normalization of plasma lactic acid. There was a good clinical tolerability and an improvement in organ function. The inflammatory cytokines showed a reduction; particularly in TNF-α within a day. CONCLUSIONS At the given dosage, N. arbor-tristis showed disease-modifying activity; early clinical recovery with a decline of TNF-α and a gradual parasite clearance. Further studies with a standardised formulation for dose-searching and optimizing the treatment schedule are needed in a larger sample size. CLINICAL TRIAL REGISTRATION NO The process of trial registration had not begun when the study was conducted in 2000.
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Affiliation(s)
- Chhaya S Godse
- ICMR Advanced Centre of Reverse Pharmacology in Traditional Medicine, Medical Research Centre, Kasturba Health Society, Vile Parle (West), Mumbai 400056, India.
| | - Prakash S Tathed
- Yerala Medical Trust's Ayurvedic Medical College and Hospital (YMTA), Sector 4, Kharghar, Navi Mumbai 410210, India
| | - Sameer S Talwalkar
- CPA Lab, Hematopathology and Molecular Diagnostics Division, Louisville, KY 40220, USA
| | - Rama A Vaidya
- ICMR Advanced Centre of Reverse Pharmacology in Traditional Medicine, Medical Research Centre, Kasturba Health Society, Vile Parle (West), Mumbai 400056, India
| | - Ashok J Amonkar
- ICMR Advanced Centre of Reverse Pharmacology in Traditional Medicine, Medical Research Centre, Kasturba Health Society, Vile Parle (West), Mumbai 400056, India
| | - Akhil B Vaidya
- Centre for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA 19129, USA; ICMR Advanced Centre of Reverse Pharmacology in Traditional Medicine, Medical Research Centre, Kasturba Health Society, Vile Parle (West), Mumbai 400056, India
| | - Ashok D B Vaidya
- ICMR Advanced Centre of Reverse Pharmacology in Traditional Medicine, Medical Research Centre, Kasturba Health Society, Vile Parle (West), Mumbai 400056, India
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18
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Jenkins BJ, Daly TM, Morrisey JM, Mather MW, Vaidya AB, Bergman LW. Characterization of a Plasmodium falciparum Orthologue of the Yeast Ubiquinone-Binding Protein, Coq10p. PLoS One 2016; 11:e0152197. [PMID: 27015086 PMCID: PMC4807763 DOI: 10.1371/journal.pone.0152197] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 03/10/2016] [Indexed: 11/18/2022] Open
Abstract
Coenzyme Q (CoQ, ubiquinone) is a central electron carrier in mitochondrial respiration. CoQ is synthesized through multiple steps involving a number of different enzymes. The prevailing view that the CoQ used in respiration exists as a free pool that diffuses throughout the mitochondrial inner membrane bilayer has recently been challenged. In the yeast Saccharomyces cerevisiae, deletion of the gene encoding Coq10p results in respiration deficiency without inhibiting the synthesis of CoQ, suggesting that the Coq10 protein is critical for the delivery of CoQ to the site(s) of respiration. The precise mechanism by which this is achieved remains unknown at present. We have identified a Plasmodium orthologue of Coq10 (PfCoq10), which is predominantly expressed in trophozoite-stage parasites, and localizes to the parasite mitochondrion. Expression of PfCoq10 in the S. cerevisiae coq10 deletion strain restored the capability of the yeast to grow on respiratory substrates, suggesting a remarkable functional conservation of this protein over a vast evolutionary distance, and despite a relatively low level of amino acid sequence identity. As the antimalarial drug atovaquone acts as a competitive inhibitor of CoQ, we assessed whether over-expression of PfCoq10 altered the atovaquone sensitivity in parasites and in yeast mitochondria, but found no alteration of its activity.
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Affiliation(s)
- Bethany J. Jenkins
- Center for Molecular Parasitology, Drexel University College of Medicine, Philadelphia, PA, United States of America
| | - Thomas M. Daly
- Center for Molecular Parasitology, Drexel University College of Medicine, Philadelphia, PA, United States of America
| | - Joanne M. Morrisey
- Center for Molecular Parasitology, Drexel University College of Medicine, Philadelphia, PA, United States of America
| | - Michael W. Mather
- Center for Molecular Parasitology, Drexel University College of Medicine, Philadelphia, PA, United States of America
| | - Akhil B. Vaidya
- Center for Molecular Parasitology, Drexel University College of Medicine, Philadelphia, PA, United States of America
| | - Lawrence W. Bergman
- Center for Molecular Parasitology, Drexel University College of Medicine, Philadelphia, PA, United States of America
- * E-mail:
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19
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Stickles AM, Ting LM, Morrisey JM, Li Y, Mather MW, Meermeier E, Pershing AM, Forquer IP, Miley GP, Pou S, Winter RW, Hinrichs DJ, Kelly JX, Kim K, Vaidya AB, Riscoe MK, Nilsen A. Inhibition of cytochrome bc1 as a strategy for single-dose, multi-stage antimalarial therapy. Am J Trop Med Hyg 2015; 92:1195-201. [PMID: 25918204 PMCID: PMC4458825 DOI: 10.4269/ajtmh.14-0553] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Accepted: 02/13/2015] [Indexed: 11/07/2022] Open
Abstract
Single-dose therapies for malaria have been proposed as a way to reduce the cost and increase the effectiveness of antimalarial treatment. However, no compound to date has shown single-dose activity against both the blood-stage Plasmodium parasites that cause disease and the liver-stage parasites that initiate malaria infection. Here, we describe a subset of cytochrome bc1 (cyt bc1) inhibitors, including the novel 4(1H)-quinolone ELQ-400, with single-dose activity against liver, blood, and transmission-stage parasites in mouse models of malaria. Although cyt bc1 inhibitors are generally classified as slow-onset antimalarials, we found that a single dose of ELQ-400 rapidly induced stasis in blood-stage parasites, which was associated with a rapid reduction in parasitemia in vivo. ELQ-400 also exhibited a low propensity for drug resistance and was active against atovaquone-resistant P. falciparum strains with point mutations in cyt bc1. Ultimately, ELQ-400 shows that cyt bc1 inhibitors can function as single-dose, blood-stage antimalarials and is the first compound to provide combined treatment, prophylaxis, and transmission blocking activity for malaria after a single oral administration. This remarkable multi-stage efficacy suggests that metabolic therapies, including cyt bc1 inhibitors, may be valuable additions to the collection of single-dose antimalarials in current development.
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Affiliation(s)
- Allison M Stickles
- Departments of Physiology and Pharmacology, Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, Oregon; Departments of Medicine, Pathology, and Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York; Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania; VA Medical Center, Portland, Oregon
| | - Li-Min Ting
- Departments of Physiology and Pharmacology, Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, Oregon; Departments of Medicine, Pathology, and Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York; Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania; VA Medical Center, Portland, Oregon
| | - Joanne M Morrisey
- Departments of Physiology and Pharmacology, Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, Oregon; Departments of Medicine, Pathology, and Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York; Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania; VA Medical Center, Portland, Oregon
| | - Yuexin Li
- Departments of Physiology and Pharmacology, Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, Oregon; Departments of Medicine, Pathology, and Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York; Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania; VA Medical Center, Portland, Oregon
| | - Michael W Mather
- Departments of Physiology and Pharmacology, Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, Oregon; Departments of Medicine, Pathology, and Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York; Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania; VA Medical Center, Portland, Oregon
| | - Erin Meermeier
- Departments of Physiology and Pharmacology, Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, Oregon; Departments of Medicine, Pathology, and Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York; Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania; VA Medical Center, Portland, Oregon
| | - April M Pershing
- Departments of Physiology and Pharmacology, Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, Oregon; Departments of Medicine, Pathology, and Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York; Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania; VA Medical Center, Portland, Oregon
| | - Isaac P Forquer
- Departments of Physiology and Pharmacology, Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, Oregon; Departments of Medicine, Pathology, and Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York; Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania; VA Medical Center, Portland, Oregon
| | - Galen P Miley
- Departments of Physiology and Pharmacology, Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, Oregon; Departments of Medicine, Pathology, and Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York; Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania; VA Medical Center, Portland, Oregon
| | - Sovitj Pou
- Departments of Physiology and Pharmacology, Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, Oregon; Departments of Medicine, Pathology, and Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York; Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania; VA Medical Center, Portland, Oregon
| | - Rolf W Winter
- Departments of Physiology and Pharmacology, Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, Oregon; Departments of Medicine, Pathology, and Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York; Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania; VA Medical Center, Portland, Oregon
| | - David J Hinrichs
- Departments of Physiology and Pharmacology, Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, Oregon; Departments of Medicine, Pathology, and Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York; Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania; VA Medical Center, Portland, Oregon
| | - Jane X Kelly
- Departments of Physiology and Pharmacology, Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, Oregon; Departments of Medicine, Pathology, and Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York; Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania; VA Medical Center, Portland, Oregon
| | - Kami Kim
- Departments of Physiology and Pharmacology, Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, Oregon; Departments of Medicine, Pathology, and Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York; Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania; VA Medical Center, Portland, Oregon
| | - Akhil B Vaidya
- Departments of Physiology and Pharmacology, Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, Oregon; Departments of Medicine, Pathology, and Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York; Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania; VA Medical Center, Portland, Oregon
| | - Michael K Riscoe
- Departments of Physiology and Pharmacology, Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, Oregon; Departments of Medicine, Pathology, and Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York; Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania; VA Medical Center, Portland, Oregon
| | - Aaron Nilsen
- Departments of Physiology and Pharmacology, Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, Oregon; Departments of Medicine, Pathology, and Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York; Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania; VA Medical Center, Portland, Oregon
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20
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Ke H, Lewis IA, Morrisey JM, McLean KJ, Ganesan SM, Painter HJ, Mather MW, Jacobs-Lorena M, Llinás M, Vaidya AB. Genetic investigation of tricarboxylic acid metabolism during the Plasmodium falciparum life cycle. Cell Rep 2015; 11:164-74. [PMID: 25843709 DOI: 10.1016/j.celrep.2015.03.011] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Revised: 02/11/2015] [Accepted: 03/04/2015] [Indexed: 12/24/2022] Open
Abstract
New antimalarial drugs are urgently needed to control drug-resistant forms of the malaria parasite Plasmodium falciparum. Mitochondrial electron transport is the target of both existing and new antimalarials. Herein, we describe 11 genetic knockout (KO) lines that delete six of the eight mitochondrial tricarboxylic acid (TCA) cycle enzymes. Although all TCA KOs grew normally in asexual blood stages, these metabolic deficiencies halted life-cycle progression in later stages. Specifically, aconitase KO parasites arrested as late gametocytes, whereas α-ketoglutarate-dehydrogenase-deficient parasites failed to develop oocysts in the mosquitoes. Mass spectrometry analysis of (13)C-isotope-labeled TCA mutant parasites showed that P. falciparum has significant flexibility in TCA metabolism. This flexibility manifested itself through changes in pathway fluxes and through altered exchange of substrates between cytosolic and mitochondrial pools. Our findings suggest that mitochondrial metabolic plasticity is essential for parasite development.
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Affiliation(s)
- Hangjun Ke
- Center for Molecular Parasitology, Drexel University College of Medicine, Philadelphia, PA 19129, USA
| | - Ian A Lewis
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
| | - Joanne M Morrisey
- Center for Molecular Parasitology, Drexel University College of Medicine, Philadelphia, PA 19129, USA
| | - Kyle J McLean
- Department of Molecular Microbiology and Immunology, Johns Hopkins School of Public Health, Baltimore, MD 21205, USA
| | - Suresh M Ganesan
- Center for Molecular Parasitology, Drexel University College of Medicine, Philadelphia, PA 19129, USA
| | - Heather J Painter
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
| | - Michael W Mather
- Center for Molecular Parasitology, Drexel University College of Medicine, Philadelphia, PA 19129, USA
| | - Marcelo Jacobs-Lorena
- Department of Molecular Microbiology and Immunology, Johns Hopkins School of Public Health, Baltimore, MD 21205, USA
| | - Manuel Llinás
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Akhil B Vaidya
- Center for Molecular Parasitology, Drexel University College of Medicine, Philadelphia, PA 19129, USA.
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21
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Vaidya AB, Morrisey JM, Zhang Z, Das S, Daly TM, Otto TD, Spillman NJ, Wyvratt M, Siegl P, Marfurt J, Wirjanata G, Sebayang BF, Price RN, Chatterjee A, Nagle A, Stasiak M, Charman SA, Angulo-Barturen I, Ferrer S, Belén Jiménez-Díaz M, Martínez MS, Gamo FJ, Avery VM, Ruecker A, Delves M, Kirk K, Berriman M, Kortagere S, Burrows J, Fan E, Bergman LW. Pyrazoleamide compounds are potent antimalarials that target Na+ homeostasis in intraerythrocytic Plasmodium falciparum. Nat Commun 2014; 5:5521. [PMID: 25422853 PMCID: PMC4263321 DOI: 10.1038/ncomms6521] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2014] [Accepted: 10/09/2014] [Indexed: 01/01/2023] Open
Abstract
The quest for new antimalarial drugs, especially those with novel modes of action, is essential in the face of emerging drug-resistant parasites. Here we describe a new chemical class of molecules, pyrazoleamides, with potent activity against human malaria parasites and showing remarkably rapid parasite clearance in an in vivo model. Investigations involving pyrazoleamide-resistant parasites, whole-genome sequencing and gene transfers reveal that mutations in two proteins, a calcium-dependent protein kinase (PfCDPK5) and a P-type cation-ATPase (PfATP4), are necessary to impart full resistance to these compounds. A pyrazoleamide compound causes a rapid disruption of Na+ regulation in blood-stage Plasmodium falciparum parasites. Similar effect on Na+ homeostasis was recently reported for spiroindolones, which are antimalarials of a chemical class quite distinct from pyrazoleamides. Our results reveal that disruption of Na+ homeostasis in malaria parasites is a promising mode of antimalarial action mediated by at least two distinct chemical classes. Novel antimalarial drugs are urgently needed to combat parasite drug resistance. Here, Vaidya et al. describe a new chemical class of potent antimalarial compounds that act by disrupting the parasite's sodium homeostasis.
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Affiliation(s)
- Akhil B Vaidya
- Department of Microbiology and Immunology, Center for Molecular Parasitology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, Pennsylvania 190129, USA
| | - Joanne M Morrisey
- Department of Microbiology and Immunology, Center for Molecular Parasitology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, Pennsylvania 190129, USA
| | - Zhongsheng Zhang
- Department of Biochemistry, University of Washington, Box 357350, Seattle, Washington 98195, USA
| | - Sudipta Das
- Department of Microbiology and Immunology, Center for Molecular Parasitology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, Pennsylvania 190129, USA
| | - Thomas M Daly
- Department of Microbiology and Immunology, Center for Molecular Parasitology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, Pennsylvania 190129, USA
| | - Thomas D Otto
- Wellcome Trust Sanger Institute, Hinxton, Cambridge CB101SA, UK
| | - Natalie J Spillman
- Research School of Biology, The Australian National University, Canberra, Australian Capital Territory 0200, Australia
| | - Matthew Wyvratt
- Medicines for Malaria Venture, PO Box 1826, 20Rt de Pr-Bois, Geneva 15 1215, Switzerland
| | - Peter Siegl
- Medicines for Malaria Venture, PO Box 1826, 20Rt de Pr-Bois, Geneva 15 1215, Switzerland
| | - Jutta Marfurt
- Division of Global and Tropical Health, Menzies School of Health Research and Charles Darwin University, PO Box 41096, Casuarina, Northern Territory 0811, Australia
| | - Grennady Wirjanata
- Division of Global and Tropical Health, Menzies School of Health Research and Charles Darwin University, PO Box 41096, Casuarina, Northern Territory 0811, Australia
| | - Boni F Sebayang
- Eijkman Institute for Molecular Biology, Jl. Diponegoro 69, Jakarta 10430, Indonesia
| | - Ric N Price
- 1] Division of Global and Tropical Health, Menzies School of Health Research and Charles Darwin University, PO Box 41096, Casuarina, Northern Territory 0811, Australia [2] Nuffield Department of Clinical Medicine, Centre for Tropical Medicine, University of Oxford, Oxford OX3 7LJ, UK
| | - Arnab Chatterjee
- Genomics Institute of the Novartis Research Foundation, 10675 John Jay Hopkins Drive, San Diego, California 92121, USA
| | - Advait Nagle
- Genomics Institute of the Novartis Research Foundation, 10675 John Jay Hopkins Drive, San Diego, California 92121, USA
| | - Marcin Stasiak
- Department of Biochemistry, University of Washington, Box 357350, Seattle, Washington 98195, USA
| | - Susan A Charman
- Center for Drug Candidate Optimisation, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Iñigo Angulo-Barturen
- GlaxoSmithKline, Malaria Support Group, Calle Severo Ochoa 2, Tres Cantos 28760, Spain
| | - Santiago Ferrer
- GlaxoSmithKline, Malaria Support Group, Calle Severo Ochoa 2, Tres Cantos 28760, Spain
| | | | - María Santos Martínez
- GlaxoSmithKline, Malaria Support Group, Calle Severo Ochoa 2, Tres Cantos 28760, Spain
| | - Francisco Javier Gamo
- GlaxoSmithKline, Malaria Support Group, Calle Severo Ochoa 2, Tres Cantos 28760, Spain
| | - Vicky M Avery
- Eskitis Institute, Griffith University, Don Young Road, Nathan, Queensland 4111, Australia
| | - Andrea Ruecker
- Department of Life Sciences, South Kensington Campus, Imperial College, London SW7 2AZ, UK
| | - Michael Delves
- Department of Life Sciences, South Kensington Campus, Imperial College, London SW7 2AZ, UK
| | - Kiaran Kirk
- Research School of Biology, The Australian National University, Canberra, Australian Capital Territory 0200, Australia
| | | | - Sandhya Kortagere
- Department of Microbiology and Immunology, Center for Molecular Parasitology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, Pennsylvania 190129, USA
| | - Jeremy Burrows
- Medicines for Malaria Venture, PO Box 1826, 20Rt de Pr-Bois, Geneva 15 1215, Switzerland
| | - Erkang Fan
- Department of Biochemistry, University of Washington, Box 357350, Seattle, Washington 98195, USA
| | - Lawrence W Bergman
- Department of Microbiology and Immunology, Center for Molecular Parasitology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, Pennsylvania 190129, USA
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22
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Ke H, Sigala PA, Miura K, Morrisey JM, Mather MW, Crowley JR, Henderson JP, Goldberg DE, Long CA, Vaidya AB. The heme biosynthesis pathway is essential for Plasmodium falciparum development in mosquito stage but not in blood stages. J Biol Chem 2014; 289:34827-37. [PMID: 25352601 DOI: 10.1074/jbc.m114.615831] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Heme is an essential cofactor for aerobic organisms. Its redox chemistry is central to a variety of biological functions mediated by hemoproteins. In blood stages, malaria parasites consume most of the hemoglobin inside the infected erythrocytes, forming nontoxic hemozoin crystals from large quantities of heme released during digestion. At the same time, the parasites possess a heme de novo biosynthetic pathway. This pathway in the human malaria parasite Plasmodium falciparum has been considered essential and is proposed as a potential drug target. However, we successfully disrupted the first and last genes of the pathway, individually and in combination. These knock-out parasite lines, lacking 5-aminolevulinic acid synthase and/or ferrochelatase (FC), grew normally in blood-stage culture and exhibited no changes in sensitivity to heme-related antimalarial drugs. We developed a sensitive LC-MS/MS assay to monitor stable isotope incorporation into heme from its precursor 5-[(13)C4]aminolevulinic acid, and this assay confirmed that de novo heme synthesis was ablated in FC knock-out parasites. Disrupting the FC gene also caused no defects in gametocyte generation or maturation but resulted in a greater than 70% reduction in male gamete formation and completely prevented oocyst formation in female Anopheles stephensi mosquitoes. Our data demonstrate that the heme biosynthesis pathway is not essential for asexual blood-stage growth of P. falciparum parasites but is required for mosquito transmission. Drug inhibition of pathway activity is therefore unlikely to provide successful antimalarial therapy. These data also suggest the existence of a parasite mechanism for scavenging host heme to meet metabolic needs.
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Affiliation(s)
- Hangjun Ke
- From the Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19129
| | - Paul A Sigala
- the Department of Molecular Microbiology and the Howard Hughes Medical Institute, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Kazutoyo Miura
- the Laboratory of Malaria and Vector Research, NIAID, National Institutes of Health, Rockville, Maryland 20852, and
| | - Joanne M Morrisey
- From the Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19129
| | - Michael W Mather
- From the Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19129
| | - Jan R Crowley
- the Center for Women's Infectious Disease Research and
| | - Jeffrey P Henderson
- the Center for Women's Infectious Disease Research and Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Daniel E Goldberg
- the Department of Molecular Microbiology and the Howard Hughes Medical Institute, Washington University School of Medicine, St. Louis, Missouri 63110, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Carole A Long
- the Laboratory of Malaria and Vector Research, NIAID, National Institutes of Health, Rockville, Maryland 20852, and
| | - Akhil B Vaidya
- From the Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19129,
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23
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Nilsen A, Miley GP, Forquer IP, Mather MW, Katneni K, Li Y, Pou S, Pershing AM, Stickles AM, Ryan E, Kelly JX, Doggett JS, White KL, Hinrichs DJ, Winter RW, Charman SA, Zakharov LN, Bathurst I, Burrows JN, Vaidya AB, Riscoe MK. Discovery, synthesis, and optimization of antimalarial 4(1H)-quinolone-3-diarylethers. J Med Chem 2014; 57:3818-34. [PMID: 24720377 PMCID: PMC4018401 DOI: 10.1021/jm500147k] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
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The
historical antimalarial compound endochin served as a structural lead
for optimization. Endochin-like quinolones (ELQ) were prepared by
a novel chemical route and assessed for in vitro activity against
multidrug resistant strains of Plasmodium falciparum and against malaria infections in mice. Here we describe the pathway
to discovery of a potent class of orally active antimalarial 4(1H)-quinolone-3-diarylethers. The initial prototype, ELQ-233,
exhibited low nanomolar IC50 values against all tested
strains including clinical isolates harboring resistance to atovaquone.
ELQ-271 represented the next critical step in the iterative optimization
process, as it was stable to metabolism and highly effective in vivo.
Continued analoging revealed that the substitution pattern on the
benzenoid ring of the quinolone core significantly influenced reactivity
with the host enzyme. This finding led to the rational design of highly
selective ELQs with outstanding oral efficacy against murine malaria
that is superior to established antimalarials chloroquine and atovaquone.
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Affiliation(s)
- Aaron Nilsen
- VA Medical Center , 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, United States
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24
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Nilsen A, LaCrue AN, White KL, Forquer IP, Cross RM, Marfurt J, Mather MW, Delves MJ, Shackleford DM, Saenz FE, Morrisey JM, Steuten J, Mutka T, Li Y, Wirjanata G, Ryan E, Duffy S, Kelly JX, Sebayang BF, Zeeman AM, Noviyanti R, Sinden RE, Kocken CHM, Price RN, Avery VM, Angulo-Barturen I, Jiménez-Díaz MB, Ferrer S, Herreros E, Sanz LM, Gamo FJ, Bathurst I, Burrows JN, Siegl P, Guy RK, Winter RW, Vaidya AB, Charman SA, Kyle DE, Manetsch R, Riscoe MK. Quinolone-3-diarylethers: a new class of antimalarial drug. Sci Transl Med 2013; 5:177ra37. [PMID: 23515079 DOI: 10.1126/scitranslmed.3005029] [Citation(s) in RCA: 164] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The goal for developing new antimalarial drugs is to find a molecule that can target multiple stages of the parasite's life cycle, thus impacting prevention, treatment, and transmission of the disease. The 4(1H)-quinolone-3-diarylethers are selective potent inhibitors of the parasite's mitochondrial cytochrome bc1 complex. These compounds are highly active against the human malaria parasites Plasmodium falciparum and Plasmodium vivax. They target both the liver and blood stages of the parasite as well as the forms that are crucial for disease transmission, that is, the gametocytes, the zygote, the ookinete, and the oocyst. Selected as a preclinical candidate, ELQ-300 has good oral bioavailability at efficacious doses in mice, is metabolically stable, and is highly active in blocking transmission in rodent models of malaria. Given its predicted low dose in patients and its predicted long half-life, ELQ-300 has potential as a new drug for the treatment, prevention, and, ultimately, eradication of human malaria.
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Affiliation(s)
- Aaron Nilsen
- VA Medical Center, 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, USA
| | - Alexis N LaCrue
- Department of Global Health, College of Public Health, 3720 Spectrum Blvd. (Ste 304), Tampa, FL 33612, USA
| | - Karen L White
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | - Isaac P Forquer
- VA Medical Center, 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, USA
| | - Richard M Cross
- Department of Chemistry, University of South Florida, 4202 E. Fowler Avenue, Tampa, FL 33620-5250, USA
| | - Jutta Marfurt
- Global Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia
| | - Michael W Mather
- Department of Microbiology and Immunology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, PA 19129, USA
| | - Michael J Delves
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - David M Shackleford
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | - Fabian E Saenz
- Department of Global Health, College of Public Health, 3720 Spectrum Blvd. (Ste 304), Tampa, FL 33612, USA
| | - Joanne M Morrisey
- Department of Microbiology and Immunology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, PA 19129, USA
| | - Jessica Steuten
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | - Tina Mutka
- Department of Global Health, College of Public Health, 3720 Spectrum Blvd. (Ste 304), Tampa, FL 33612, USA
| | - Yuexin Li
- VA Medical Center, 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, USA
| | - Grennady Wirjanata
- Global Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia
| | - Eileen Ryan
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | - Sandra Duffy
- Eskitis Institute for Cell & Molecular Therapies, Brisbane Innovation Park, Nathan campus, Griffith University, QLD 4111, Australia
| | - Jane Xu Kelly
- VA Medical Center, 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, USA
| | - Boni F Sebayang
- Eijkman Institute for Molecular Biology, Jl. Diponegoro 69, Jakarta 10430, Indonesia
| | - Anne-Marie Zeeman
- Department of Parasitology, Biomedical Primate Research Centre, P.O. Box 3306, 2280 GH Rijswijk, The Netherlands
| | - Rintis Noviyanti
- Eijkman Institute for Molecular Biology, Jl. Diponegoro 69, Jakarta 10430, Indonesia
| | - Robert E Sinden
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Clemens H M Kocken
- Department of Parasitology, Biomedical Primate Research Centre, P.O. Box 3306, 2280 GH Rijswijk, The Netherlands
| | - Ric N Price
- Global Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia.,Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, University of Oxford, Oxford OX3 7LJ, UK
| | - Vicky M Avery
- Eskitis Institute for Cell & Molecular Therapies, Brisbane Innovation Park, Nathan campus, Griffith University, QLD 4111, Australia
| | - Iñigo Angulo-Barturen
- GlaxoSmithKline, Medicines Development Campus, Diseases of the Developing World, Severo Ochoa 2, Tres Cantos 28760, Madrid, Spain
| | - María Belén Jiménez-Díaz
- GlaxoSmithKline, Medicines Development Campus, Diseases of the Developing World, Severo Ochoa 2, Tres Cantos 28760, Madrid, Spain
| | - Santiago Ferrer
- GlaxoSmithKline, Medicines Development Campus, Diseases of the Developing World, Severo Ochoa 2, Tres Cantos 28760, Madrid, Spain
| | - Esperanza Herreros
- GlaxoSmithKline, Medicines Development Campus, Diseases of the Developing World, Severo Ochoa 2, Tres Cantos 28760, Madrid, Spain
| | - Laura M Sanz
- GlaxoSmithKline, Medicines Development Campus, Diseases of the Developing World, Severo Ochoa 2, Tres Cantos 28760, Madrid, Spain
| | - Francisco-Javier Gamo
- GlaxoSmithKline, Medicines Development Campus, Diseases of the Developing World, Severo Ochoa 2, Tres Cantos 28760, Madrid, Spain
| | - Ian Bathurst
- Medicines for Malaria Venture, 20, route de Pré-Bois, PO Box 1826, 1215 Geneva 15, Switzerland
| | - Jeremy N Burrows
- Medicines for Malaria Venture, 20, route de Pré-Bois, PO Box 1826, 1215 Geneva 15, Switzerland
| | - Peter Siegl
- Siegl Pharma Consulting LLC, Blue Bell, PA, USA
| | - R Kiplin Guy
- Chemical Biology & Therapeutics, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105-3678 USA
| | - Rolf W Winter
- VA Medical Center, 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, USA
| | - Akhil B Vaidya
- Department of Microbiology and Immunology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, PA 19129, USA
| | - Susan A Charman
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | - Dennis E Kyle
- Department of Global Health, College of Public Health, 3720 Spectrum Blvd. (Ste 304), Tampa, FL 33612, USA
| | - Roman Manetsch
- Department of Chemistry, University of South Florida, 4202 E. Fowler Avenue, Tampa, FL 33620-5250, USA
| | - Michael K Riscoe
- VA Medical Center, 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, USA.,Department of Molecular Microbiology and Immunology, 3181 Sam Jackson Blvd., Portland, Oregon 97239, USA
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25
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Sheiner L, Vaidya AB, McFadden GI. The metabolic roles of the endosymbiotic organelles of Toxoplasma and Plasmodium spp. Curr Opin Microbiol 2013; 16:452-8. [PMID: 23927894 DOI: 10.1016/j.mib.2013.07.003] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 07/02/2013] [Accepted: 07/04/2013] [Indexed: 11/29/2022]
Abstract
The apicoplast and the mitochondrion of Apicomplexa cooperate in providing essential metabolites. Their co-evolution during the ancestral acquisition of a plastid and subsequent loss of photosynthesis resulted in divergent metabolic pathways compared with mammals and plants. This is most evident in their chimerical haem synthesis pathway. Toxoplasma and Plasmodium mitochondria operate canonical tricarboxylic acid (TCA) cycles and electron transport chains, although the roles differ between Toxoplasma tachyzoites and Plasmodium erythrocytic stages. Glutamine catabolism provides TCA intermediates in both parasites. Isoprenoid precursor synthesis is the only essential role of the apicoplast in Plasmodium erythrocytic stages. An apicoplast-located fatty acid synthesis is dispensable in these stages, which instead predominantly salvage fatty acids, while in Plasmodium liver stages and in Toxoplasma tachyzoites fatty acid synthesis is an essential role of the plastid.
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Affiliation(s)
- Lilach Sheiner
- Center for Tropical and Emerging Global Diseases & Department of Cellular Biology, University of Georgia, 500 D.W. Brooks Drive, Athens, GA 30602, USA.
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Olszewski KL, Mather MW, Morrisey JM, Garcia BA, Vaidya AB, Rabinowitz JD, Llinás M. Retraction: Branched tricarboxylic acid metabolism in Plasmodium falciparum. Nature 2013; 497:652. [PMID: 23615611 DOI: 10.1038/nature12164] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Cernetich-Ott A, Daly TM, Vaidya AB, Bergman LW, Burns JM. Remarkable stability in patterns of blood-stage gene expression during episodes of non-lethal Plasmodium yoelii malaria. Malar J 2012; 11:265. [PMID: 22866913 PMCID: PMC3489522 DOI: 10.1186/1475-2875-11-265] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2012] [Accepted: 07/22/2012] [Indexed: 11/12/2022] Open
Abstract
Background Microarray studies using in vitro cultures of synchronized, blood-stage Plasmodium falciparum malaria parasites have revealed a ‘just-in-time’ cascade of gene expression with some indication that these transcriptional patterns remain stable even in the presence of external stressors. However, direct analysis of transcription in P. falciparum blood-stage parasites obtained from the blood of infected patients suggests that parasite gene expression may be modulated by factors present in the in vivo environment of the host. The aim of this study was to examine changes in gene expression of the rodent malaria parasite, Plasmodium yoelii 17X, while varying the in vivo setting of replication. Methods Using P. yoelii 17X parasites replicating in vivo, differential gene expression in parasites isolated from individual mice, from independent infections, during ascending, peak and descending parasitaemia and in the presence and absence of host antibody responses was examined using P. yoelii DNA microarrays. A genome-wide analysis to identify coordinated changes in groups of genes associated with specific biological pathways was a primary focus, although an analysis of the expression patterns of two multi-gene families in P. yoelii, the yir and pyst-a families, was also completed. Results Across experimental conditions, transcription was surprisingly stable with little evidence for distinct transcriptional states or for consistent changes in specific pathways. Differential gene expression was greatest when comparing differences due to parasite load and/or host cell availability. However, the number of differentially expressed genes was generally low. Of genes that were differentially expressed, many involved biologically diverse pathways. There was little to no differential expression of members of the yir and pyst-a multigene families that encode polymorphic proteins associated with the membrane of infected erythrocytes. However, a relatively large number of these genes were expressed during blood-stage infection regardless of experimental condition. Conclusions Taken together, these results indicate that 1) P. yoelii gene expression remains stable in the presence of a changing host environment, and 2) concurrent expression of a large number of the polymorphic yir and pyst-a genes, rather than differential expression in response to specific host factors, may in itself limit the effectiveness of host immune responses.
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Affiliation(s)
- Amy Cernetich-Ott
- Centre for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, PA 19129, USA
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Ke H, Morrisey JM, Ganesan SM, Mather MW, Vaidya AB. Mitochondrial RNA polymerase is an essential enzyme in erythrocytic stages of Plasmodium falciparum. Mol Biochem Parasitol 2012; 185:48-51. [PMID: 22640832 DOI: 10.1016/j.molbiopara.2012.05.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2011] [Revised: 05/07/2012] [Accepted: 05/16/2012] [Indexed: 11/27/2022]
Abstract
We have shown that transgenic Plasmodium falciparum parasites expressing the yeast DHODH (dihydroorotate dehydrogenase) are independent of the mtETC (mitochondrial electron transport chain), suggesting that they might not need the mitochondrial genome (mtDNA), since it only encodes three protein subunits belonging to the mtETC and fragmentary ribosomal RNA molecules. Disrupting the mitochondrial RNA polymerase (mtRNAP), which is critical for mtDNA replication and transcription, might then cause the generation of a ρ(0) parasite line lacking mtDNA. We made multiple attempts to disrupt the mtRNAP gene by double crossover recombination methods in parasite lines expressing yDHODH either episomally or integrated in the genome, but were unable to produce the desired knockout. We verified that the mtRNAP gene was accessible to recombination by successfully integrating a triple HA tag at the 3' end via single cross-over recombination. These studies suggest that mtRNAP is essential even in mtETC-independent P. falciparum parasites.
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Affiliation(s)
- Hangjun Ke
- Center for Molecular Parasitology and Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA 19129, USA
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Bosch J, Paige MH, Vaidya AB, Bergman LW, Hol WGJ. Crystal structure of GAP50, the anchor of the invasion machinery in the inner membrane complex of Plasmodium falciparum. J Struct Biol 2012; 178:61-73. [PMID: 22387043 DOI: 10.1016/j.jsb.2012.02.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2011] [Revised: 02/08/2012] [Accepted: 02/10/2012] [Indexed: 10/28/2022]
Abstract
The glideosome associated protein GAP50 is an essential protein in apicomplexan parasites such as Plasmodium, Toxoplasma and Cryptosporidium, several species of which are important human pathogens. The 44.6kDa protein is part of a multi-protein complex known as the invasion machinery or glideosome, which is required for cell invasion and substrate gliding motility empowered by an actin-myosin motor. GAP50 is anchored through its C-terminal transmembrane helix into the inner membrane complex and interacts via a short six residue C-terminal tail with other proteins of the invasion machinery in the pellicle of the parasite. In this paper we describe the 1.7Å resolution crystal structure of the soluble GAP50 domain from the malaria parasite Plasmodium falciparum. The structure shows an αßßα fold with overall similarity to purple acid phosphatases with, however, little homology regarding the nature of the residues in the active site region of the latter enzyme. While purple acid phosphatases contain a phosphate bridged binuclear Fe-site coordinated by seven side chains with the Fe-ions 3.2Å apart, GAP50 in our crystals contains two cobalt ions each with one protein ligand and a distance between the Co(2+) ions of 18Å.
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Affiliation(s)
- Jürgen Bosch
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA
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Nam TG, McNamara CW, Bopp S, Dharia NV, Meister S, Bonamy GMC, Plouffe DM, Kato N, McCormack S, Bursulaya B, Ke H, Vaidya AB, Schultz PG, Winzeler EA. A chemical genomic analysis of decoquinate, a Plasmodium falciparum cytochrome b inhibitor. ACS Chem Biol 2011; 6:1214-22. [PMID: 21866942 PMCID: PMC3220786 DOI: 10.1021/cb200105d] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
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Decoquinate has single-digit nanomolar activity against in vitro blood stage Plasmodium falciparum parasites, the causative agent of human malaria. In vitro evolution of decoquinate-resistant parasites and subsequent comparative genomic analysis to the drug-sensitive parental strain revealed resistance was conferred by two nonsynonymous single nucleotide polymorphisms in the gene encoding cytochrome b. The resultant amino acid mutations, A122T and Y126C, reside within helix C in the ubiquinol-binding pocket of cytochrome b, an essential subunit of the cytochrome bc1 complex. As with other cytochrome bc1 inhibitors, such as atovaquone, decoquinate has low nanomolar activity against in vitro liver stage P. yoelii and provides partial prophylaxis protection when administered to infected mice at 50 mg kg–1. In addition, transgenic parasites expressing yeast dihydroorotate dehydrogenase are >200-fold less sensitive to decoquinate, which provides additional evidence that this drug inhibits the parasite’s mitochondrial electron transport chain. Importantly, decoquinate exhibits limited cross-resistance to a panel of atovaquone-resistant parasites evolved to harbor various mutations in cytochrome b. The basis for this difference was revealed by molecular docking studies, in which both of these inhibitors were shown to have distinctly different modes of binding within the ubiquinol-binding site of cytochrome b.
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Affiliation(s)
| | - Case W. McNamara
- Genomics Institute of the Novartis Research Foundation, 10675 John Jay Hopkins Drive, San Diego, California 92121, United States
| | | | | | | | - Ghislain M. C. Bonamy
- Genomics Institute of the Novartis Research Foundation, 10675 John Jay Hopkins Drive, San Diego, California 92121, United States
| | - David M. Plouffe
- Genomics Institute of the Novartis Research Foundation, 10675 John Jay Hopkins Drive, San Diego, California 92121, United States
| | - Nobutaka Kato
- Genomics Institute of the Novartis Research Foundation, 10675 John Jay Hopkins Drive, San Diego, California 92121, United States
| | - Susan McCormack
- Genomics Institute of the Novartis Research Foundation, 10675 John Jay Hopkins Drive, San Diego, California 92121, United States
| | - Badry Bursulaya
- Genomics Institute of the Novartis Research Foundation, 10675 John Jay Hopkins Drive, San Diego, California 92121, United States
| | - Hangjun Ke
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19129, United States
| | - Akhil B. Vaidya
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19129, United States
| | - Peter G. Schultz
- Genomics Institute of the Novartis Research Foundation, 10675 John Jay Hopkins Drive, San Diego, California 92121, United States
| | - Elizabeth A. Winzeler
- Genomics Institute of the Novartis Research Foundation, 10675 John Jay Hopkins Drive, San Diego, California 92121, United States
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Coyne RS, Hannick L, Shanmugam D, Hostetler JB, Brami D, Joardar VS, Johnson J, Radune D, Singh I, Badger JH, Kumar U, Saier M, Wang Y, Cai H, Gu J, Mather MW, Vaidya AB, Wilkes DE, Rajagopalan V, Asai DJ, Pearson CG, Findly RC, Dickerson HW, Wu M, Martens C, Van de Peer Y, Roos DS, Cassidy-Hanley DM, Clark TG. Comparative genomics of the pathogenic ciliate Ichthyophthirius multifiliis, its free-living relatives and a host species provide insights into adoption of a parasitic lifestyle and prospects for disease control. Genome Biol 2011; 12:R100. [PMID: 22004680 PMCID: PMC3341644 DOI: 10.1186/gb-2011-12-10-r100] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Revised: 09/15/2011] [Accepted: 10/17/2011] [Indexed: 01/09/2023] Open
Abstract
Background Ichthyophthirius multifiliis, commonly known as Ich, is a highly pathogenic ciliate responsible for 'white spot', a disease causing significant economic losses to the global aquaculture industry. Options for disease control are extremely limited, and Ich's obligate parasitic lifestyle makes experimental studies challenging. Unlike most well-studied protozoan parasites, Ich belongs to a phylum composed primarily of free-living members. Indeed, it is closely related to the model organism Tetrahymena thermophila. Genomic studies represent a promising strategy to reduce the impact of this disease and to understand the evolutionary transition to parasitism. Results We report the sequencing, assembly and annotation of the Ich macronuclear genome. Compared with its free-living relative T. thermophila, the Ich genome is reduced approximately two-fold in length and gene density and three-fold in gene content. We analyzed in detail several gene classes with diverse functions in behavior, cellular function and host immunogenicity, including protein kinases, membrane transporters, proteases, surface antigens and cytoskeletal components and regulators. We also mapped by orthology Ich's metabolic pathways in comparison with other ciliates and a potential host organism, the zebrafish Danio rerio. Conclusions Knowledge of the complete protein-coding and metabolic potential of Ich opens avenues for rational testing of therapeutic drugs that target functions essential to this parasite but not to its fish hosts. Also, a catalog of surface protein-encoding genes will facilitate development of more effective vaccines. The potential to use T. thermophila as a surrogate model offers promise toward controlling 'white spot' disease and understanding the adaptation to a parasitic lifestyle.
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Affiliation(s)
- Robert S Coyne
- Genomic Medicine, J Craig Venter Institute, Rockville, MD 20850, USA.
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Nina PB, Morrisey JM, Ganesan SM, Ke H, Pershing AM, Mather MW, Vaidya AB. ATP synthase complex of Plasmodium falciparum: dimeric assembly in mitochondrial membranes and resistance to genetic disruption. J Biol Chem 2011; 286:41312-41322. [PMID: 21984828 DOI: 10.1074/jbc.m111.290973] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The rotary nanomotor ATP synthase is a central player in the bioenergetics of most organisms. Yet the role of ATP synthase in malaria parasites has remained unclear, as blood stages of Plasmodium falciparum appear to derive ATP largely through glycolysis. Also, genes for essential subunits of the F(O) sector of the complex could not be detected in the parasite genomes. Here, we have used molecular genetic and immunological tools to investigate the localization, complex formation, and functional significance of predicted ATP synthase subunits in P. falciparum. We generated transgenic P. falciparum lines expressing seven epitope-tagged canonical ATP synthase subunits, revealing localization of all but one of the subunits to the mitochondrion. Blue native gel electrophoresis of P. falciparum mitochondrial membranes suggested the molecular mass of the ATP synthase complex to be greater than 1 million daltons. This size is consistent with the complex being assembled as a dimer in a manner similar to the complexes observed in other eukaryotic organisms. This observation also suggests the presence of previously unknown subunits in addition to the canonical subunits in P. falciparum ATP synthase complex. Our attempts to disrupt genes encoding β and γ subunits were unsuccessful, suggesting an essential role played by the ATP synthase complex in blood stages of P. falciparum. These studies suggest that, despite some unconventional features and its minimal contribution to ATP synthesis, P. falciparum ATP synthase is localized to the parasite mitochondrion, assembled as a large dimeric complex, and is likely essential for parasite survival.
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Affiliation(s)
- Praveen Balabaskaran Nina
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19129
| | - Joanne M Morrisey
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19129
| | - Suresh M Ganesan
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19129
| | - Hangjun Ke
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19129
| | - April M Pershing
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19129
| | - Michael W Mather
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19129
| | - Akhil B Vaidya
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19129.
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Joshi JV, Paradkar PH, Jagtap SS, Agashe SV, Soman G, Vaidya AB. Chemopreventive potential and safety profile of a Curcuma longa extract in women with cervical low-grade squamous intraepithelial neoplasia. Asian Pac J Cancer Prev 2011; 12:3305-3311. [PMID: 22471471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023] Open
Abstract
OBJECTIVE To determine whether Curcuma longa Linn extract, NBFR-03, can arrest low-grade squamous intraepithelial neoplasia (LSIL) a 12 week intervention study was performed. METHODS Of a total of 1473 women undergoing Pap smear screening, 88 cases had LSIL. Only those with persistent LSIL subsequent to antimicrobial therapy, and willing to follow the protocol (N=21), were included for clinical examination, Pap smears, colposcopy, clinical biochemistry, urinalysis and assessment of serum IL-6, being conducted before and after treatment. Standardised NBFR-03 (0.2gm) capsules were administered, twice daily, for 12 weeks. RESULTS None progressed to higher grade lesion as assessed by Pap smears and colposcopy. Sixteen cases regressed to atypia, ASCUS or inflammatory pattern; 3 persisted as LSIL, 1 discontinued early because of itching, and 1 did not start. None developed any significant abnormality clinically or biochemically. Micrometry showed a significant reduction in nuclear diameter and nucleocytoplasmic ratio after treatment (p<0.02, and <0.05 respectively). Serum IL-6 levels showed a significant decline (mean 248∓ 156 (SEM) vs 27.7∓ 10.5 (SEM) pg/ ml; p<0.05). CONCLUSION Use of NBFR-03 for 12 weeks was associated with an arrest or regression of LSIL in Pap smears and colposcopy, with reduction in the circulating IL-6 levels.
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Affiliation(s)
- J V Joshi
- Medical Research Center, Kasturba, India
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Olszewski KL, Mather MW, Morrisey JM, Garcia BA, Vaidya AB, Rabinowitz JD, Llinás M. Erratum: Branched tricarboxylic acid metabolism in Plasmodium falciparum. Nature 2011. [DOI: 10.1038/nature09712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Kortagere S, Welsh WJ, Morrisey JM, Daly T, Ejigiri I, Sinnis P, Vaidya AB, Bergman LW. Structure-based design of novel small-molecule inhibitors of Plasmodium falciparum. J Chem Inf Model 2010; 50:840-9. [PMID: 20426475 DOI: 10.1021/ci100039k] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Malaria is endemic in most developing countries, with nearly 500 million cases estimated to occur each year. The need to design a new generation of antimalarial drugs that can combat the most drug-resistant forms of the malarial parasite is well recognized. In this study, we wanted to develop inhibitors of key proteins that form the invasion machinery of the malarial parasite. A critical feature of host-cell invasion by apicomplexan parasites is the interaction between the carboxy terminal tail of myosin A (MyoA) and the myosin tail interacting protein (MTIP). Using the cocrystal structure of the Plasmodium knowlesi MTIP and the MyoA tail peptide as input to the hybrid structure-based virtual screening approach, we identified a series of small molecules as having the potential to inhibit MTIP-MyoA interactions. Of the initial 15 compounds tested, a pyrazole-urea compound inhibited P. falciparum growth with an EC(50) value of 145 nM. We screened an additional 51 compounds belonging to the same chemical class and identified 8 compounds with EC(50) values less than 400 nM. Interestingly, the compounds appeared to act at several stages of the parasite's life cycle to block growth and development. The pyrazole-urea compounds identified in this study could be effective antimalarial agents because they competitively inhibit a key protein-protein interaction between MTIP and MyoA responsible for the gliding motility and the invasive features of the malarial parasite.
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Affiliation(s)
- Sandhya Kortagere
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, Pennsylvania, USA.
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Olszewski KL, Mather MW, Morrisey JM, Garcia BA, Vaidya AB, Rabinowitz JD, Llinás M. Branched tricarboxylic acid metabolism in Plasmodium falciparum. Nature 2010; 466:774-8. [PMID: 20686576 PMCID: PMC2917841 DOI: 10.1038/nature09301] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Accepted: 06/11/2010] [Indexed: 12/25/2022]
Abstract
A central hub of carbon metabolism is the tricarboxylic acid cycle, which serves to connect the processes of glycolysis, gluconeogenesis, respiration, amino acid synthesis and other biosynthetic pathways. The protozoan intracellular malaria parasites (Plasmodium spp.), however, have long been suspected of possessing a significantly streamlined carbon metabolic network in which tricarboxylic acid metabolism plays a minor role. Blood-stage Plasmodium parasites rely almost entirely on glucose fermentation for energy and consume minimal amounts of oxygen, yet the parasite genome encodes all of the enzymes necessary for a complete tricarboxylic acid cycle. Here, by tracing (13)C-labelled compounds using mass spectrometry we show that tricarboxylic acid metabolism in the human malaria parasite Plasmodium falciparum is largely disconnected from glycolysis and is organized along a fundamentally different architecture from the canonical textbook pathway. We find that this pathway is not cyclic, but rather is a branched structure in which the major carbon sources are the amino acids glutamate and glutamine. As a consequence of this branched architecture, several reactions must run in the reverse of the standard direction, thereby generating two-carbon units in the form of acetyl-coenzyme A. We further show that glutamine-derived acetyl-coenzyme A is used for histone acetylation, whereas glucose-derived acetyl-coenzyme A is used to acetylate amino sugars. Thus, the parasite has evolved two independent production mechanisms for acetyl-coenzyme A with different biological functions. These results significantly clarify our understanding of the Plasmodium metabolic network and highlight the ability of altered variants of central carbon metabolism to arise in response to unique environments.
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Affiliation(s)
- Kellen L. Olszewski
- Department of Molecular Biology & Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544
| | - Michael W. Mather
- Center for Molecular Parasitology, Drexel University College of Medicine, Philadelphia, PA 19129
| | - Joanne M. Morrisey
- Center for Molecular Parasitology, Drexel University College of Medicine, Philadelphia, PA 19129
| | - Benjamin A. Garcia
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544
| | - Akhil B. Vaidya
- Center for Molecular Parasitology, Drexel University College of Medicine, Philadelphia, PA 19129
| | - Joshua D. Rabinowitz
- Department of Chemistry & Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544
| | - Manuel Llinás
- Department of Molecular Biology & Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544
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Mather MW, Morrisey JM, Vaidya AB. Hemozoin-free Plasmodium falciparum mitochondria for physiological and drug susceptibility studies. Mol Biochem Parasitol 2010; 174:150-3. [PMID: 20674615 DOI: 10.1016/j.molbiopara.2010.07.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Revised: 07/19/2010] [Accepted: 07/22/2010] [Indexed: 11/18/2022]
Abstract
Isolation of mitochondria of high purity and with intact enzymatic activities from malaria parasites has proven to be a major obstacle in characterizing the parasite mitochondrial physiology. We describe here an improved procedure for the isolation of a mitochondrially enriched preparation from the trophozoite stage of erythrocytic Plasmodium falciparum, combining disruption by N(2) cavitation and differential centrifugation with magnetic removal of hemozoin-associated material. These mitochondrial preparations may be used to assay various mitochondrial enzyme activities, such as succinate and dihydroorotate dehydrogenases, ubiquinol-cytochrome c oxidoreductase, and cytochrome c oxidase. They also exhibit a low level of ATPase activity, which is only marginally inhibited by classical inhibitors. We have used this preparation to determine the susceptibility of mitochondrial activities to drugs and drug candidate compounds in both "wild type" and transgenic parasites.
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Affiliation(s)
- Michael W Mather
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA 19129, USA.
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Balabaskaran Nina P, Dudkina NV, Kane LA, van Eyk JE, Boekema EJ, Mather MW, Vaidya AB. Highly divergent mitochondrial ATP synthase complexes in Tetrahymena thermophila. PLoS Biol 2010; 8:e1000418. [PMID: 20644710 PMCID: PMC2903591 DOI: 10.1371/journal.pbio.1000418] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2010] [Accepted: 06/01/2010] [Indexed: 12/28/2022] Open
Abstract
The F-type ATP synthase complex is a rotary nano-motor driven by proton motive force to synthesize ATP. Its F(1) sector catalyzes ATP synthesis, whereas the F(o) sector conducts the protons and provides a stator for the rotary action of the complex. Components of both F(1) and F(o) sectors are highly conserved across prokaryotes and eukaryotes. Therefore, it was a surprise that genes encoding the a and b subunits as well as other components of the F(o) sector were undetectable in the sequenced genomes of a variety of apicomplexan parasites. While the parasitic existence of these organisms could explain the apparent incomplete nature of ATP synthase in Apicomplexa, genes for these essential components were absent even in Tetrahymena thermophila, a free-living ciliate belonging to a sister clade of Apicomplexa, which demonstrates robust oxidative phosphorylation. This observation raises the possibility that the entire clade of Alveolata may have invented novel means to operate ATP synthase complexes. To assess this remarkable possibility, we have carried out an investigation of the ATP synthase from T. thermophila. Blue native polyacrylamide gel electrophoresis (BN-PAGE) revealed the ATP synthase to be present as a large complex. Structural study based on single particle electron microscopy analysis suggested the complex to be a dimer with several unique structures including an unusually large domain on the intermembrane side of the ATP synthase and novel domains flanking the c subunit rings. The two monomers were in a parallel configuration rather than the angled configuration previously observed in other organisms. Proteomic analyses of well-resolved ATP synthase complexes from 2-D BN/BN-PAGE identified orthologs of seven canonical ATP synthase subunits, and at least 13 novel proteins that constitute subunits apparently limited to the ciliate lineage. A mitochondrially encoded protein, Ymf66, with predicted eight transmembrane domains could be a substitute for the subunit a of the F(o) sector. The absence of genes encoding orthologs of the novel subunits even in apicomplexans suggests that the Tetrahymena ATP synthase, despite core similarities, is a unique enzyme exhibiting dramatic differences compared to the conventional complexes found in metazoan, fungal, and plant mitochondria, as well as in prokaryotes. These findings have significant implications for the origins and evolution of a central player in bioenergetics.
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Affiliation(s)
- Praveen Balabaskaran Nina
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Natalya V. Dudkina
- Department of Biophysical Chemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, The Netherlands
| | - Lesley A. Kane
- Department of Medicine, The Johns Hopkins University, Baltimore, Maryland, United States of America
- Department of Biological Chemistry, The Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Jennifer E. van Eyk
- Department of Medicine, The Johns Hopkins University, Baltimore, Maryland, United States of America
- Department of Biological Chemistry, The Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Egbert J. Boekema
- Department of Biophysical Chemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, The Netherlands
| | - Michael W. Mather
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Akhil B. Vaidya
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
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39
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Affiliation(s)
- Akhil B. Vaidya
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19129;
| | - Michael W. Mather
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19129;
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40
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Olszewski KL, Morrisey JM, Wilinski D, Burns JM, Vaidya AB, Rabinowitz JD, Llinás M. Host-parasite interactions revealed by Plasmodium falciparum metabolomics. Cell Host Microbe 2009; 5:191-9. [PMID: 19218089 DOI: 10.1016/j.chom.2009.01.004] [Citation(s) in RCA: 207] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2008] [Revised: 12/19/2008] [Accepted: 01/22/2009] [Indexed: 01/25/2023]
Abstract
Intracellular pathogens have devised mechanisms to exploit their host cells to ensure their survival and replication. The malaria parasite Plasmodium falciparum relies on an exchange of metabolites with the host for proliferation. Here we describe a mass spectrometry-based metabolomic analysis of the parasite throughout its 48 hr intraerythrocytic developmental cycle. Our results reveal a general modulation of metabolite levels by the parasite, with numerous metabolites varying in phase with the developmental cycle. Others differed from uninfected cells irrespective of the developmental stage. Among these was extracellular arginine, which was specifically converted to ornithine by the parasite. To identify the biochemical basis for this effect, we disrupted the plasmodium arginase gene in the rodent malaria model P. berghei. These parasites were viable but did not convert arginine to ornithine. Our results suggest that systemic arginine depletion by the parasite may be a factor in human malarial hypoargininemia associated with cerebral malaria pathogenesis.
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Affiliation(s)
- Kellen L Olszewski
- Department of Molecular Biology, 2Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
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41
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Alkhalil A, Pillai AD, Bokhari AAB, Vaidya AB, Desai SA. Complex inheritance of the plasmodial surface anion channel in a Plasmodium falciparum genetic cross. Mol Microbiol 2009; 72:459-69. [PMID: 19320831 DOI: 10.1111/j.1365-2958.2009.06661.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Human erythrocytes infected with the malaria parasite Plasmodium falciparum have increased permeabilities to many solutes. The plasmodial surface anion channel (PSAC) may mediate these changes. Despite good understanding of the biochemical and biophysical properties, the genetic basis of PSAC activity remains unknown. Functional polymorphisms in laboratory isolates and two mutants generated by in vitro selection implicate a parasite-encoded channel, although parasite-induced modifications of endogenous channels have not been formally excluded. Here, we identified stable differences in furosemide efficacy against PSAC activity induced by HB3 and 3D7A parasites. This difference was apparent in both single PSAC patch-clamp recordings and in sorbitol-mediated osmotic lysis measurements, confirming that Cl(-) and sorbitol are transported by a single-channel type. Examination of 19 progeny from a genetic cross between HB3 and 3D7A revealed complex inheritance with some cloned progeny exhibiting furosemide affinities outside the range of parental values. Isolates generated by selfing of the 3D7A clone also exhibited altered furosemide affinities, implicating changes in one or more alleles during meiosis or passage through a primate host. PSAC may be encoded by multiple parasite genes (e.g. a multi-gene family or multiple genes that encode distinct channel subunits) or a single polymorphic gene under strong selective pressure.
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Affiliation(s)
- Abdulnaser Alkhalil
- The Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, NIH, Rockville, MD 20852, USA
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42
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Mather MW, Vaidya AB. Mitochondria in malaria and related parasites: ancient, diverse and streamlined. J Bioenerg Biomembr 2008; 40:425-33. [PMID: 18814021 DOI: 10.1007/s10863-008-9176-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2008] [Accepted: 08/23/2008] [Indexed: 10/21/2022]
Abstract
Parasitic organisms have emerged from nearly every corner of the eukaryotic kingdom and hence display tremendous diversity of form and function. This diversity extends to their mitochondria and mitochondrion-derived organelles. While the principles of the chemiosmotic theory apply to all these pathogens, the differences from their hosts provide opportunities for therapeutic development. In this review we discuss examples of mitochondrial systems from a deep-branching phylum, Apicomplexa. Many important human pathogens, such as malaria parasites, belong to this phylum. Unique features of their mitochondria are validated targets for drugs that are selectively toxic to the parasites.
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Affiliation(s)
- Michael W Mather
- Department of Microbiology and Immunology, Center for Molecular Parasitology, Drexel University College of Medicine, Philadelphia, PA 19129, USA.
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43
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Vaidya AB, Painter HJ, Morrisey JM, Mather MW. The validity of mitochondrial dehydrogenases as antimalarial drug targets. Trends Parasitol 2008; 24:8-9. [DOI: 10.1016/j.pt.2007.10.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2007] [Revised: 09/07/2007] [Accepted: 10/11/2007] [Indexed: 11/26/2022]
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Abstract
In evolutionary terms, mitochondria in apicomplexan parasites appear to be "relicts-in-the-making": they possess the smallest mitochondrial genomes known, encoding only three proteins, and in one genus, Cryptosporidium, the genome is eliminated altogether. Several features of mitochondrial physiology provide validated or potential targets for antiparasitic drugs. Atovaquone, a broad spectrum antiparasitic drug, selectively inhibits mitochondrial electron transport at the cytochrome bc(1) complex and collapses mitochondrial membrane potential. Recent investigations using model systems provide important insights into the mechanism of action for this drug, which may prove valuable for development of other selective inhibitors of mitochondrial electron transport. Although mitochondria do not appear to be a source of ATP during the erythrocytic stages in Plasmodium species, they do serve other critical functions, including the assembly of iron-sulfur clusters and various other biosynthetic processes depending on the species. To serve these metabolic functions, parasites need to maintain the apparatus for mitochondrial genome replication, repair, recombination, transcription, and translation, components of which are encoded in the nucleus and imported into the mitochondrion. Several unusual aspects of the components of this apparatus are coming to light through genome sequence analyses, and could provide potential targets for antiparasitic drug discovery and development.
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Affiliation(s)
- Michael W Mather
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, Pennsylvania 19129, USA
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45
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Painter HJ, Morrisey JM, Mather MW, Vaidya AB. Specific role of mitochondrial electron transport in blood-stage Plasmodium falciparum. Nature 2007; 446:88-91. [PMID: 17330044 DOI: 10.1038/nature05572] [Citation(s) in RCA: 333] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2006] [Accepted: 01/05/2007] [Indexed: 11/08/2022]
Abstract
The origin of all mitochondria can be traced to the symbiotic arrangement that resulted in the emergence of eukaryotes in a world that was exclusively populated by prokaryotes. This arrangement, however, has been in continuous genetic flux: the varying degrees of gene loss and transfer from the mitochondrial genome in different eukaryotic lineages seem to signify an ongoing 'conflict' between the host and the symbiont. Eukaryotic parasites belonging to the phylum Apicomplexa provide an excellent example to support this view. These organisms contain the smallest mitochondrial genomes known, with an organization that differs among various genera; one genus, Cryptosporidium, seems to have lost the entire mitochondrial genome. Here we show that erythrocytic stages of the human malaria parasite Plasmodium falciparum seem to maintain an active mitochondrial electron transport chain to serve just one metabolic function: regeneration of ubiquinone required as the electron acceptor for dihydroorotate dehydrogenase, an essential enzyme for pyrimidine biosynthesis. Transgenic P. falciparum parasites expressing Saccharomyces cerevisiae dihydroorotate dehydrogenase, which does not require ubiquinone as an electron acceptor, were completely resistant to inhibitors of mitochondrial electron transport. Maintenance of mitochondrial membrane potential, however, was essential in these parasites, as indicated by their hypersensitivity to proguanil, a drug that collapsed the membrane potential in the presence of electron transport inhibitors. Thus, acquisition of just one enzyme can render mitochondrial electron transport nonessential in erythrocytic stages of P. falciparum.
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Affiliation(s)
- Heather J Painter
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19129, USA
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46
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Gogtay NJ, Kshirsagar NA, Vaidya AB. Current challenges in drug-resistant malaria. J Postgrad Med 2006; 52:241-2. [PMID: 17102539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023] Open
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Abstract
Mitochondria in Plasmodium parasites have many characteristics that distinguish them from mammalian mitochondria. Selective targeting of malaria parasite mitochondrial physiology has been exploited in successful antimalarial chemotherapy. At present, our understanding of the functions served by the parasite mitochondrion is somewhat limited, but the availability of the genomic sequences makes it possible to develop a framework of possible mitochondrial functions by providing information on genes encoding mitochondrially targeted proteins. This review aims to provide an overview of mitochondrial physiology in this post-genomic era. Although in many cases direct experimental proof for their mitochondrial functions may not be available at present, descriptions of these potential mitochondrial proteins can provide a basis for experimental approaches.
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Affiliation(s)
- A B Vaidya
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, PA 19129, USA.
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48
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Bosch J, Turley S, Daly TM, Bogh SM, Villasmil ML, Roach C, Zhou N, Morrisey JM, Vaidya AB, Bergman LW, Hol WGJ. Structure of the MTIP-MyoA complex, a key component of the malaria parasite invasion motor. Proc Natl Acad Sci U S A 2006; 103:4852-7. [PMID: 16547135 PMCID: PMC1458759 DOI: 10.1073/pnas.0510907103] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2005] [Indexed: 11/18/2022] Open
Abstract
The causative agents of malaria have developed a sophisticated machinery for entering multiple cell types in the human and insect hosts. In this machinery, a critical interaction occurs between the unusual myosin motor MyoA and the MyoA-tail Interacting Protein (MTIP). Here we present one crystal structure that shows three different conformations of Plasmodium MTIP, one of these in complex with the MyoA-tail, which reveal major conformational changes in the C-terminal domain of MTIP upon binding the MyoA-tail helix, thereby creating several hydrophobic pockets in MTIP that are the recipients of key hydrophobic side chains of MyoA. Because we also show that the MyoA helix is able to block parasite growth, this provides avenues for designing antimalarials.
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Affiliation(s)
- Jürgen Bosch
- Departments of *Biochemistry and Biological Structure and
- Structural Genomics of Pathogenic Protozoa (SGPP), and
| | - Stewart Turley
- Departments of *Biochemistry and Biological Structure and
- Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195; and
| | - Thomas M. Daly
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA 19129
| | - Stephen M. Bogh
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA 19129
| | - Michelle L. Villasmil
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA 19129
| | - Claudia Roach
- Departments of *Biochemistry and Biological Structure and
- Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195; and
| | - Na Zhou
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA 19129
| | - Joanne M. Morrisey
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA 19129
| | - Akhil B. Vaidya
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA 19129
| | - Lawrence W. Bergman
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA 19129
| | - Wim G. J. Hol
- Departments of *Biochemistry and Biological Structure and
- Structural Genomics of Pathogenic Protozoa (SGPP), and
- Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195; and
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49
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Shi Q, Cernetich A, Daly TM, Galvan G, Vaidya AB, Bergman LW, Burns JM. Alteration in host cell tropism limits the efficacy of immunization with a surface protein of malaria merozoites. Infect Immun 2005; 73:6363-71. [PMID: 16177307 PMCID: PMC1230925 DOI: 10.1128/iai.73.10.6363-6371.2005] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Immunization with Plasmodium yoelii merozoite surface protein-8 (PyMSP-8) has been shown to protect mice against lethal P. yoelii 17XL malaria. Here we demonstrate that PyMSP-8-specific antibodies preferentially suppress P. yoelii 17XL growth in mature erythrocytes compared to growth in reticulocytes and do not suppress the growth of nonlethal P. yoelii 17X, a parasite that primarily replicates in reticulocytes. The protection against normocyte-associated P. yoelii malaria parasites is mediated by antibodies that recognize conformational epitopes of PyMSP-8 that are nonpolymorphic. We examined changes in gene expression in reticulocyte-restricted P. yoelii 17XL parasites that escaped neutralization by PyMSP-8-specific antibodies using P. yoelii DNA microarrays. Of interest, Pymsp-8 gene expression decreased, while the expression of msp-1, msp-7, and several rhoptry protein genes increased. Breakthrough parasites also exhibited increases in the expression of a subset of yir and Pyst-a genes that are predicted to encode polymorphic antigens expressed on the surface of infected erythrocytes. These data suggest that changes in the expression of parasite proteins expressed on the merozoite surface, as well as the surface of infected erythrocytes, may alter host cell tropism and contribute to the ability of malaria parasites to evade merozoite-specific, neutralizing antibodies.
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Affiliation(s)
- Qifang Shi
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19129, USA
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50
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Furuya T, Mu J, Hayton K, Liu A, Duan J, Nkrumah L, Joy DA, Fidock DA, Fujioka H, Vaidya AB, Wellems TE, Su XZ. Disruption of a Plasmodium falciparum gene linked to male sexual development causes early arrest in gametocytogenesis. Proc Natl Acad Sci U S A 2005; 102:16813-8. [PMID: 16275909 PMCID: PMC1277966 DOI: 10.1073/pnas.0501858102] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A male gametocyte defect in the Plasmodium falciparum Dd2 parasite was previously discovered through the observation that all progeny clones in a Dd2 x HB3 genetic cross were the result of fertilization events between Dd2 female and HB3 male gametes. A determinant linked to the defect in Dd2 was subsequently mapped to an 800-kb segment on chromosome 12. Here, we report further mapping of the determinant to an 82-kb region and the identification of a candidate gene, P. falciparum male development gene 1 (pfmdv-1), that is expressed at a lower level in Dd2 compared with the wild-type normal male gametocyte-producing ancestor W2. Pfmdv-1 protein is sexual-stage specific and is located on the gametocyte plasma membrane, parasitophorous vacuole membrane, and the membranes of cleft-like structures within the erythrocyte. Disruption of pfmdv-1 results in a dramatic reduction in mature gametocytes, especially functional male gametocytes, with the majority of sexually committed parasites developmentally arrested at stage I. The pfmdv-1-knockout parasites show disturbed membrane structures, particularly multimembrane vesicles/tubes that likely derive from deformed cleft-like structures. Mosquito infectivity of the knockout parasites was also greatly reduced but not completely lost. The results suggest that pfmdv-1 plays a key role in gametocyte membrane formation and integrity.
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Affiliation(s)
- Tetsuya Furuya
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892-8132, USA
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