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Mok S, Stokes BH, Gnädig NF, Ross LS, Yeo T, Amaratunga C, Allman E, Solyakov L, Bottrill AR, Tripathi J, Fairhurst RM, Llinás M, Bozdech Z, Tobin AB, Fidock DA. Artemisinin-resistant K13 mutations rewire Plasmodium falciparum's intra-erythrocytic metabolic program to enhance survival. Nat Commun 2021; 12:530. [PMID: 33483501 PMCID: PMC7822823 DOI: 10.1038/s41467-020-20805-w] [Citation(s) in RCA: 63] [Impact Index Per Article: 21.0] [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: 07/28/2020] [Accepted: 12/17/2020] [Indexed: 12/15/2022] Open
Abstract
The emergence and spread of artemisinin resistance, driven by mutations in Plasmodium falciparum K13, has compromised antimalarial efficacy and threatens the global malaria elimination campaign. By applying systems-based quantitative transcriptomics, proteomics, and metabolomics to a panel of isogenic K13 mutant or wild-type P. falciparum lines, we provide evidence that K13 mutations alter multiple aspects of the parasite's intra-erythrocytic developmental program. These changes impact cell-cycle periodicity, the unfolded protein response, protein degradation, vesicular trafficking, and mitochondrial metabolism. K13-mediated artemisinin resistance in the Cambodian Cam3.II line was reversed by atovaquone, a mitochondrial electron transport chain inhibitor. These results suggest that mitochondrial processes including damage sensing and anti-oxidant properties might augment the ability of mutant K13 to protect P. falciparum against artemisinin action by helping these parasites undergo temporary quiescence and accelerated growth recovery post drug elimination.
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Affiliation(s)
- Sachel Mok
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY, USA
| | - Barbara H Stokes
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY, USA
| | - Nina F Gnädig
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY, USA
| | - Leila S Ross
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY, USA
| | - Tomas Yeo
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY, USA
| | - Chanaki Amaratunga
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Erik Allman
- Department of Biochemistry & Molecular Biology, Huck Center for Malaria Research, Pennsylvania State University, University Park, PA, USA
| | - Lev Solyakov
- Protein Nucleic Acid Laboratory, University of Leicester, Leicester, UK
| | - Andrew R Bottrill
- Protein Nucleic Acid Laboratory, University of Leicester, Leicester, UK
| | - Jaishree Tripathi
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Rick M Fairhurst
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.,Astra Zeneca, Gaithersburg, MD, 20878, USA
| | - Manuel Llinás
- Department of Biochemistry & Molecular Biology, Huck Center for Malaria Research, Pennsylvania State University, University Park, PA, USA.,Department of Chemistry, Huck Center for Malaria Research, Pennsylvania State University, University Park, PA, USA
| | - Zbynek Bozdech
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Andrew B Tobin
- The Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - David A Fidock
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY, USA. .,Division of Infectious Diseases, Department of Medicine, Columbia University Irving Medical Center, New York, NY, USA.
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2
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Alam MM, Sanchez-Azqueta A, Janha O, Flannery EL, Mahindra A, Mapesa K, Char AB, Sriranganadane D, Brancucci NMB, Antonova-Koch Y, Crouch K, Simwela NV, Millar SB, Akinwale J, Mitcheson D, Solyakov L, Dudek K, Jones C, Zapatero C, Doerig C, Nwakanma DC, Vázquez MJ, Colmenarejo G, Lafuente-Monasterio MJ, Leon ML, Godoi PHC, Elkins JM, Waters AP, Jamieson AG, Álvaro EF, Ranford-Cartwright LC, Marti M, Winzeler EA, Gamo FJ, Tobin AB. Validation of the protein kinase PfCLK3 as a multistage cross-species malarial drug target. Science 2019; 365:365/6456/eaau1682. [PMID: 31467193 DOI: 10.1126/science.aau1682] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 03/15/2019] [Accepted: 07/12/2019] [Indexed: 12/26/2022]
Abstract
The requirement for next-generation antimalarials to be both curative and transmission-blocking necessitates the identification of previously undiscovered druggable molecular pathways. We identified a selective inhibitor of the Plasmodium falciparum protein kinase PfCLK3, which we used in combination with chemogenetics to validate PfCLK3 as a drug target acting at multiple parasite life stages. Consistent with a role for PfCLK3 in RNA splicing, inhibition resulted in the down-regulation of more than 400 essential parasite genes. Inhibition of PfCLK3 mediated rapid killing of asexual liver- and blood-stage P. falciparum and blockade of gametocyte development, thereby preventing transmission, and also showed parasiticidal activity against P. berghei and P. knowlesi Hence, our data establish PfCLK3 as a target for drugs, with the potential to offer a cure-to be prophylactic and transmission blocking in malaria.
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Affiliation(s)
- Mahmood M Alam
- Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow G12 8QQ, UK
| | - Ana Sanchez-Azqueta
- Centre for Translational Pharmacology, Institute of Molecular Cell and Systems Biology, University of Glasgow, Glasgow G12 8QQ, UK
| | - Omar Janha
- Centre for Translational Pharmacology, Institute of Molecular Cell and Systems Biology, University of Glasgow, Glasgow G12 8QQ, UK
| | - Erika L Flannery
- Novartis Institute for Biomedical Research, Emeryville, CA 94608, USA
| | - Amit Mahindra
- School of Chemistry, University of Glasgow, Glasgow G12 8QQ, UK
| | - Kopano Mapesa
- School of Chemistry, University of Glasgow, Glasgow G12 8QQ, UK
| | - Aditya B Char
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Science, University of Glasgow, Glasgow G12 8QQ, UK
| | - Dev Sriranganadane
- Structural Genomics Consortium, Universidade Estadual de Campinas, Campinas, São Paulo 13083-886, Brazil
| | - Nicolas M B Brancucci
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, 4051 Basel, Switzerland
| | - Yevgeniya Antonova-Koch
- Skaggs School of Pharmaceutical Sciences, UC Health Sciences Center for Immunology, Infection and Inflammation, University of California, San Diego, School of Medicine, La Jolla, CA 92093, USA
| | - Kathryn Crouch
- Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow G12 8QQ, UK
| | - Nelson Victor Simwela
- Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow G12 8QQ, UK
| | - Scott B Millar
- Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow G12 8QQ, UK
| | - Jude Akinwale
- Medical Research Council Toxicology Unit, University of Leicester, Leicester LE1 9HN, UK
| | - Deborah Mitcheson
- Department of Molecular Cell Biology, University of Leicester, Leicester LE1 9HN, UK
| | - Lev Solyakov
- Medical Research Council Toxicology Unit, University of Leicester, Leicester LE1 9HN, UK
| | - Kate Dudek
- Medical Research Council Toxicology Unit, University of Leicester, Leicester LE1 9HN, UK
| | - Carolyn Jones
- Medical Research Council Toxicology Unit, University of Leicester, Leicester LE1 9HN, UK
| | - Cleofé Zapatero
- Diseases of the Developing World, GlaxoSmithKline, 28760 Tres Cantos, Madrid, Spain
| | - Christian Doerig
- Biomedical Science Cluster, School of Health and Biomedical Sciences, Royal Melbourne Institute of Technology, Melbourne, VIC 3000, Australia
| | | | - Maria Jesús Vázquez
- Diseases of the Developing World, GlaxoSmithKline, 28760 Tres Cantos, Madrid, Spain
| | - Gonzalo Colmenarejo
- Biostatistics and Bioinformatics Unit, IMDEA Food Institute, 28049 Madrid, Spain
| | | | - Maria Luisa Leon
- Diseases of the Developing World, GlaxoSmithKline, 28760 Tres Cantos, Madrid, Spain
| | - Paulo H C Godoi
- Structural Genomics Consortium, Universidade Estadual de Campinas, Campinas, São Paulo 13083-886, Brazil
| | - Jon M Elkins
- Structural Genomics Consortium, Nuffield Department of Clinical Medicine, University of Oxford, Oxford OX3 7DQ, UK
| | - Andrew P Waters
- Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow G12 8QQ, UK
| | | | | | - Lisa C Ranford-Cartwright
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Science, University of Glasgow, Glasgow G12 8QQ, UK
| | - Matthias Marti
- Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow G12 8QQ, UK
| | - Elizabeth A Winzeler
- Skaggs School of Pharmaceutical Sciences, UC Health Sciences Center for Immunology, Infection and Inflammation, University of California, San Diego, School of Medicine, La Jolla, CA 92093, USA
| | | | - Andrew B Tobin
- Centre for Translational Pharmacology, Institute of Molecular Cell and Systems Biology, University of Glasgow, Glasgow G12 8QQ, UK.
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Graciotti M, Alam M, Solyakov L, Schmid R, Burley G, Bottrill AR, Doerig C, Cullis P, Tobin AB. Malaria protein kinase CK2 (PfCK2) shows novel mechanisms of regulation. PLoS One 2014; 9:e85391. [PMID: 24658579 PMCID: PMC3962329 DOI: 10.1371/journal.pone.0085391] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Accepted: 12/05/2013] [Indexed: 11/19/2022] Open
Abstract
Casein kinase 2 (protein kinase CK2) is a conserved eukaryotic serine/theronine kinase with multiple substrates and roles in the regulation of cellular processes such as cellular stress, cell proliferation and apoptosis. Here we report a detailed analysis of the Plasmodium falciparum CK2, PfCK2, demonstrating that this kinase, like the mammalian orthologue, is a dual specificity kinase able to phosphorylate at both serine and tyrosine. However, unlike the human orthologue that is auto-phosphorylated on tyrosine within the activation loop, PfCK2 shows no activation loop auto-phosphorylation but rather is auto-phosphorylated at threonine 63 within subdomain I. Phosphorylation at this site in PfCK2 is shown here to regulate the intrinsic kinase activity of PfCK2. Furthermore, we generate an homology model of PfCK2 in complex with the known selective protein kinase CK2 inhibitor, quinalizarin, and in so doing identify key co-ordinating residues in the ATP binding pocket that could aid in designing selective inhibitors to PfCK2.
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Affiliation(s)
- Michele Graciotti
- Department of Cell Physiology and Pharmacology, University of Leicester, Leicester, United Kingdom
| | - Mahmood Alam
- Medical Research Council Toxicology Unit, University of Leicester, Leicester, United Kingdom
| | - Lev Solyakov
- Medical Research Council Toxicology Unit, University of Leicester, Leicester, United Kingdom
| | - Ralf Schmid
- Department of Biochemistry, University of Leicester, Leicester, United Kingdom
| | - Glenn Burley
- Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, United Kingdom
| | - Andrew R. Bottrill
- The Protein Nucleic Acid Chemistry Laboratory, University of Leicester, Leicester, United Kingdom
| | - Christian Doerig
- Department of Microbiology, School of Biomedical Sciences, Monash University, Clayton, Victoria, Australia
| | - Paul Cullis
- Department of Chemistry, University of Leicester, Leicester, United Kingdom
| | - Andrew B. Tobin
- Medical Research Council Toxicology Unit, University of Leicester, Leicester, United Kingdom
- * E-mail:
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4
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Hopp CS, Flueck C, Solyakov L, Tobin A, Baker DA. Spatiotemporal and functional characterisation of the Plasmodium falciparum cGMP-dependent protein kinase. PLoS One 2012; 7:e48206. [PMID: 23139764 PMCID: PMC3489689 DOI: 10.1371/journal.pone.0048206] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [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: 08/16/2012] [Accepted: 09/25/2012] [Indexed: 01/18/2023] Open
Abstract
Signalling by 3′–5′-cyclic guanosine monophosphate (cGMP) exists in virtually all eukaryotes. In the apicomplexan parasite Plasmodium, the cGMP-dependent protein kinase (PKG) has previously been reported to play a critical role in four key stages of the life cycle. The Plasmodium falciparum isoform (PfPKG) is essential for the initiation of gametogenesis and for blood stage schizont rupture and work on the orthologue from the rodent malaria parasite P. berghei (PbPKG) has shown additional roles in ookinete differentiation and motility as well as liver stage schizont development. In the present study, PfPKG expression and subcellular location in asexual blood stages was investigated using transgenic epitope-tagged PfPKG-expressing P. falciparum parasites. In Western blotting experiments and immunofluorescence analysis (IFA), maximal PfPKG expression was detected at the late schizont stage. While IFA suggested a cytosolic location, a degree of overlap with markers of the endoplasmic reticulum (ER) was found and subcellular fractionation showed some association with the peripheral membrane fraction. This broad localisation is consistent with the notion that PfPKG, as with the mammalian orthologue, has numerous cellular substrates. This idea is further supported by the global protein phosphorylation pattern of schizonts which was substantially changed following PfPKG inhibition, suggesting a complex role for PfPKG during schizogony.
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Affiliation(s)
- Christine S. Hopp
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Christian Flueck
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Lev Solyakov
- Department of Cell Physiology and Pharmacology, University of Leicester, Leicester, United Kingdom
| | - Andrew Tobin
- Department of Cell Physiology and Pharmacology, University of Leicester, Leicester, United Kingdom
| | - David A. Baker
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
- * E-mail:
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5
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Guttery DS, Poulin B, Ferguson DJP, Szöőr B, Wickstead B, Carroll PL, Ramakrishnan C, Brady D, Patzewitz EM, Straschil U, Solyakov L, Green JL, Sinden RE, Tobin AB, Holder AA, Tewari R. A unique protein phosphatase with kelch-like domains (PPKL) in Plasmodium modulates ookinete differentiation, motility and invasion. PLoS Pathog 2012; 8:e1002948. [PMID: 23028336 PMCID: PMC3447748 DOI: 10.1371/journal.ppat.1002948] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [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: 06/23/2012] [Accepted: 08/22/2012] [Indexed: 12/27/2022] Open
Abstract
Protein phosphorylation and dephosphorylation (catalysed by kinases and phosphatases, respectively) are post-translational modifications that play key roles in many eukaryotic signalling pathways, and are often deregulated in a number of pathological conditions in humans. In the malaria parasite Plasmodium, functional insights into its kinome have only recently been achieved, with over half being essential for blood stage development and another 14 kinases being essential for sexual development and mosquito transmission. However, functions for any of the plasmodial protein phosphatases are unknown. Here, we use reverse genetics in the rodent malaria model, Plasmodium berghei, to examine the role of a unique protein phosphatase containing kelch-like domains (termed PPKL) from a family related to Arabidopsis BSU1. Phylogenetic analysis confirmed that the family of BSU1-like proteins including PPKL is encoded in the genomes of land plants, green algae and alveolates, but not in other eukaryotic lineages. Furthermore, PPKL was observed in a distinct family, separate to the most closely-related phosphatase family, PP1. In our genetic approach, C-terminal GFP fusion with PPKL showed an active protein phosphatase preferentially expressed in female gametocytes and ookinetes. Deletion of the endogenous ppkl gene caused abnormal ookinete development and differentiation, and dissociated apical microtubules from the inner-membrane complex, generating an immotile phenotype and failure to invade the mosquito mid-gut epithelium. These observations were substantiated by changes in localisation of cytoskeletal tubulin and actin, and the micronemal protein CTRP in the knockout mutant as assessed by indirect immunofluorescence. Finally, increased mRNA expression of dozi, a RNA helicase vital to zygote development was observed in ppkl− mutants, with global phosphorylation studies of ookinete differentiation from 1.5–24 h post-fertilisation indicating major changes in the first hours of zygote development. Our work demonstrates a stage-specific essentiality of the unique PPKL enzyme, which modulates parasite differentiation, motility and transmission. Malaria parasites are single-celled organisms, which alternate their life-cycle between vertebrate and mosquito hosts. In the mosquito, the malaria parasite undergoes sexual development, whereby a male and female gamete fuse to form a zygote. This zygote then elongates into an invasive stage, termed an ookinete, which can glide to and penetrate the mosquito's gut wall in order to form a cyst (called an oocyst). Protein phosphorylation is known to play a vital role during this process; however, the role of Plasmodium kinases (which phosphorylate proteins) during zygote/ookinete maturation is better understood than the completely uncharacterised plasmodial phosphatases (which dephosphorylate proteins). Using a malaria parasite which infects mice, Plasmodium berghei, we show that a unique protein phosphatase containing kelch-like domains (called PPKL) plays a vital role in ookinete maturation and motility. Deleting this gene produces ookinetes whose shape is grossly abnormal, resulting in non-motile parasites that cannot penetrate the lining of the mosquito gut wall. Overall, PPKL is an essential phosphatase that is critical to ookinete development, motility and invasion.
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Affiliation(s)
- David S. Guttery
- Centre for Genetics and Genomics, School of Biology, Queens Medical Centre, University of Nottingham, Nottingham, United Kingdom
| | - Benoit Poulin
- Centre for Genetics and Genomics, School of Biology, Queens Medical Centre, University of Nottingham, Nottingham, United Kingdom
| | - David J. P. Ferguson
- Nuffield Department of Clinical Laboratory Science, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
| | - Balázs Szöőr
- Centre for Immunity, Infection and Evolution, Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Bill Wickstead
- Centre for Genetics and Genomics, School of Biology, Queens Medical Centre, University of Nottingham, Nottingham, United Kingdom
| | - Paula L. Carroll
- Centre for Genetics and Genomics, School of Biology, Queens Medical Centre, University of Nottingham, Nottingham, United Kingdom
| | - Chandra Ramakrishnan
- Division of Cell and Molecular Biology, Imperial College London, London, United Kingdom
| | - Declan Brady
- Centre for Genetics and Genomics, School of Biology, Queens Medical Centre, University of Nottingham, Nottingham, United Kingdom
| | - Eva-Maria Patzewitz
- Centre for Genetics and Genomics, School of Biology, Queens Medical Centre, University of Nottingham, Nottingham, United Kingdom
| | - Ursula Straschil
- Division of Cell and Molecular Biology, Imperial College London, London, United Kingdom
| | - Lev Solyakov
- Medical Research Council Toxicology Unit, Leicester, United Kingdom
| | - Judith L. Green
- Division of Parasitology, MRC National Institute for Medical Research, Mill Hill, London, United Kingdom
| | - Robert E. Sinden
- Division of Cell and Molecular Biology, Imperial College London, London, United Kingdom
| | - Andrew B. Tobin
- Medical Research Council Toxicology Unit, Leicester, United Kingdom
| | - Anthony A. Holder
- Division of Parasitology, MRC National Institute for Medical Research, Mill Hill, London, United Kingdom
| | - Rita Tewari
- Centre for Genetics and Genomics, School of Biology, Queens Medical Centre, University of Nottingham, Nottingham, United Kingdom
- * E-mail:
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Guttery DS, Ferguson DJP, Poulin B, Xu Z, Straschil U, Klop O, Solyakov L, Sandrini SM, Brady D, Nieduszynski CA, Janse CJ, Holder AA, Tobin AB, Tewari R. A putative homologue of CDC20/CDH1 in the malaria parasite is essential for male gamete development. PLoS Pathog 2012; 8:e1002554. [PMID: 22383885 PMCID: PMC3285604 DOI: 10.1371/journal.ppat.1002554] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [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: 09/05/2011] [Accepted: 01/12/2012] [Indexed: 11/19/2022] Open
Abstract
Cell-cycle progression is governed by a series of essential regulatory proteins. Two major regulators are cell-division cycle protein 20 (CDC20) and its homologue, CDC20 homologue 1 (CDH1), which activate the anaphase-promoting complex/cyclosome (APC/C) in mitosis, and facilitate degradation of mitotic APC/C substrates. The malaria parasite, Plasmodium, is a haploid organism which, during its life-cycle undergoes two stages of mitosis; one associated with asexual multiplication and the other with male gametogenesis. Cell-cycle regulation and DNA replication in Plasmodium was recently shown to be dependent on the activity of a number of protein kinases. However, the function of cell division cycle proteins that are also involved in this process, such as CDC20 and CDH1 is totally unknown. Here we examine the role of a putative CDC20/CDH1 in the rodent malaria Plasmodium berghei (Pb) using reverse genetics. Phylogenetic analysis identified a single putative Plasmodium CDC20/CDH1 homologue (termed CDC20 for simplicity) suggesting that Plasmodium APC/C has only one regulator. In our genetic approach to delete the endogenous cdc20 gene of P. berghei, we demonstrate that PbCDC20 plays a vital role in male gametogenesis, but is not essential for mitosis in the asexual blood stage. Furthermore, qRT-PCR analysis in parasite lines with deletions of two kinase genes involved in male sexual development (map2 and cdpk4), showed a significant increase in cdc20 transcription in activated gametocytes. DNA replication and ultra structural analyses of cdc20 and map2 mutants showed similar blockage of nuclear division at the nuclear spindle/kinetochore stage. CDC20 was phosphorylated in asexual and sexual stages, but the level of modification was higher in activated gametocytes and ookinetes. Changes in global protein phosphorylation patterns in the Δcdc20 mutant parasites were largely different from those observed in the Δmap2 mutant. This suggests that CDC20 and MAP2 are both likely to play independent but vital roles in male gametogenesis.
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Affiliation(s)
- David S. Guttery
- Centre for Genetics and Genomics, School of Biology Queens Medical Centre, University of Nottingham, Nottingham, United Kingdom
| | - David J. P. Ferguson
- Nuffield Department of Clinical Laboratory Science, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
| | - Benoit Poulin
- Centre for Genetics and Genomics, School of Biology Queens Medical Centre, University of Nottingham, Nottingham, United Kingdom
| | - Zhengyao Xu
- Centre for Genetics and Genomics, School of Biology Queens Medical Centre, University of Nottingham, Nottingham, United Kingdom
| | - Ursula Straschil
- Division of Cell and Molecular Biology, Imperial College London, London, United Kingdom
| | - Onny Klop
- Leiden Malaria Research Group, Department of Parasitology, Leiden University Medical, Leiden, The Netherlands
| | - Lev Solyakov
- Department of Cell Physiology and Pharmacology, College of Medicine, Biological Sciences and Psychology, University of Leicester, Leicester, United Kingdom
| | - Sara M. Sandrini
- Centre for Genetics and Genomics, School of Biology Queens Medical Centre, University of Nottingham, Nottingham, United Kingdom
| | - Declan Brady
- Centre for Genetics and Genomics, School of Biology Queens Medical Centre, University of Nottingham, Nottingham, United Kingdom
| | - Conrad A. Nieduszynski
- Centre for Genetics and Genomics, School of Biology Queens Medical Centre, University of Nottingham, Nottingham, United Kingdom
| | - Chris J. Janse
- Leiden Malaria Research Group, Department of Parasitology, Leiden University Medical, Leiden, The Netherlands
| | - Anthony A. Holder
- Division of Parasitology, MRC National Institute for Medical Research, London, United Kingdom
| | - Andrew B. Tobin
- Department of Cell Physiology and Pharmacology, College of Medicine, Biological Sciences and Psychology, University of Leicester, Leicester, United Kingdom
| | - Rita Tewari
- Centre for Genetics and Genomics, School of Biology Queens Medical Centre, University of Nottingham, Nottingham, United Kingdom
- Division of Cell and Molecular Biology, Imperial College London, London, United Kingdom
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7
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Abstract
The central role played by protein phosphorylation in the regulation of eukaryotic cellular processes calls for detailed investigations of this phenomenon in malaria parasites. Here, we describe protocols to measure the activity of protein kinases (using either recombinant proteins or native enzymes purified from parasite extracts), and outline procedures to identify phosphorylation sites on parasite proteins following a mass spectrometry approach.
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Solyakov L, Sayan E, Riley J, Pointon A, Tobin AB. Regulation of p53 expression, phosphorylation and subcellular localization by a G-protein-coupled receptor. Oncogene 2009; 28:3619-30. [PMID: 19648965 PMCID: PMC2875175 DOI: 10.1038/onc.2009.225] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [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: 12/31/2022]
Abstract
G-protein coupled receptors (GPCRs) have been extremely successful drug targets for a multitude of diseases from heart failure to depression. This super-family of cell surface receptors have not, however, been widely considered as a viable target in cancer treatment. In the current study we demonstrate that a classical Gq/11-coupled GPCR, the M3-muscarinic receptor, was able to regulate apoptosis via receptors that are endogenously expressed in the human neuroblastoma cell line SH-SY5Y and when ectopically expressed in Chinese hamster ovary (CHO) cells. Stimulation of the M3-muscarinic receptor was shown to inhibit the ability of the DNA-damaging chemotherapeutic agent, etoposide, from mediating apoptosis. This protective response in CHO cells correlated with the ability of the receptor to regulate the expression levels of p53. In contrast, stimulation of endogenous muscarinic receptors in SH-SY5Y cells did not regulate p53 expression but rather was able to inhibit p53 translocation to the mitochondria and p53 phosphorylation at serine 15 and 37. This study suggests the possibility that a GPCR can regulate the apoptotic properties of a chemotherapeutic DNA-damaging agent by regulating the expression, sub-cellular trafficking and modification of p53 in a manner that is in part dependent on the cell type.
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Affiliation(s)
- L Solyakov
- Department of Cell Physiology and Pharmacology, University of Leicester, Leicester, UK
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9
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Solyakov L, Cain K, Tracey BM, Jukes R, Riley AM, Potter BVL, Tobin AB. Regulation of Casein Kinase-2 (CK2) Activity by Inositol Phosphates. J Biol Chem 2004; 279:43403-10. [PMID: 15297462 DOI: 10.1074/jbc.m403239200] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Casein kinase 2 (CK2) was one of the first protein kinases to be discovered and has been suggested to be responsible for as much as one-fifth of the eukaryotic phosphoproteome. Despite being responsible for the phosphorylation of a vast array of proteins central to numerous dynamic cellular processes, the activity of CK2 appears to be unregulated. In the current study, we identified a protein kinase activity in rat liver supernatant that is up-regulated by inositol 1,3,4,5-tetrakisphosphate (IP4) and inositol hexakisphosphate (IP6). The substrate for the inositol phosphate-regulated protein kinase was identified as a phosphatidylcholine transfer protein-like protein. Using the phosphorylation of this substrate in an assay, we purified the inositol phosphate-regulated protein kinase and determined it to be CK2. Bacterially expressed recombinant CK2, however, showed very high basal activity and was only modestly activated by IP6 and not regulated by IP. We found that an endogenous component present in rat liver supernatant was able to inhibit both recombinant and liver-purified CK2 basal activity. Under these conditions, recombinant CK2 catalytic activity could be increased substantially by IP4, inositol 1,3,4,5,6-pentakisphosphate (IP5), and IP6. We concluded that, contrary to the previously held view, CK2 can exist in a state of low constitutive activity allowing for its regulation by inositol phosphates. The ability of the higher inositol phosphates to directly stimulate CK2 catalytic activity provides the first evidence that these signaling molecules can operate via a direct control of protein phosphorylation.
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Affiliation(s)
- Lev Solyakov
- Department of Cell Physiology and Pharmacology, Hodgkin Building, Lancaster Road, University of Leicester, LE1 9HN, UK
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Solyakov L, Dobrota D, Drany O, Vachova M, Machac S, Mezesova V, Bachurin S, Lombardi V. Transport mechanism of L-[14C]glutamate in cortical slices and synaptosomes of rabbits exposed to brain ischemia and reperfusion. Mol Chem Neuropathol 1995; 25:123-34. [PMID: 8534315 DOI: 10.1007/bf02960907] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Changes in the functioning of the glutamatergic system in rabbit brain were studied after partial brain ischemia and reperfusion. In vitro studies were conducted relating to the release of L-[14C]glutamate from cortical brain slices, L-[14C]glutamate uptake in synaptosomes, and 45Ca uptake in synaptosomes. It was found that basal release of L-[14C]glutamate from rabbit brain cortical slices after 30 min of partial ischemia and 1 d of reperfusion was essentially without change compared to the control values. After 3 d of reperfusion, there was an increase in basal release of L-[14C]glutamate from rabbit brain cortical slices. K+ stimulated release of L-[14C]glutamate in normal Krebs-Ringer medium was essentially the same in the control group and in the experimental group after 30 min of ischemia. The K+ stimulated release of L-[14C]glutamate independent of calcium was increased to 145% after 30 min of ischemia and 1 d of reperfusion. The decreased Km value at the glutamate transporter may have contributed to this difference. Kinetic parameters of the L-[14C]glutamate uptake (Km and Vmax) in synaptosomes from rabbit brain were significantly lower after 30 min of ischemia. The authors discovered that during the reperfusion period, Vmax was almost the same as in the control group. The activity of the Na+/Ca2+ exchanger in synaptosomes of rat brain was about 70% of the control values after 30 min of ischemia and 72 h of reperfusion. According to our results, increased L-[14C]glutamate release after 30 min of ischemia appears to be the result of higher intracellular calcium concentration and possibly also of a higher uptake of glutamate.
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Affiliation(s)
- L Solyakov
- Russian Academy of Sciences, Institute of Physiologically Active Substances, Moscow, Russia
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