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Lebepe CM, Matambanadzo PR, Makhoba XH, Achilonu I, Zininga T, Shonhai A. Comparative Characterization of Plasmodium falciparum Hsp70-1 Relative to E. coli DnaK Reveals the Functional Specificity of the Parasite Chaperone. Biomolecules 2020; 10:biom10060856. [PMID: 32512819 PMCID: PMC7356358 DOI: 10.3390/biom10060856] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 05/21/2020] [Accepted: 06/01/2020] [Indexed: 12/20/2022] Open
Abstract
Hsp70 is a conserved molecular chaperone. How Hsp70 exhibits specialized functions across species remains to be understood. Plasmodium falciparum Hsp70-1 (PfHsp70-1) and Escherichia coli DnaK are cytosol localized molecular chaperones that are important for the survival of these two organisms. In the current study, we investigated comparative structure-function features of PfHsp70-1 relative to DnaK and a chimeric protein, KPf, constituted by the ATPase domain of DnaK and the substrate binding domain (SBD) of PfHsp70-1. Recombinant forms of the three Hsp70s exhibited similar secondary and tertiary structural folds. However, compared to DnaK, both KPf and PfHsp70-1 were more stable to heat stress and exhibited higher basal ATPase activity. In addition, PfHsp70-1 preferentially bound to asparagine rich peptide substrates, as opposed to DnaK. Recombinant P. falciparum adenosylmethionine decarboxylase (PfAdoMetDC) co-expressed in E. coli with either KPf or PfHsp70-1 was produced as a fully folded product. Co-expression of PfAdoMetDC with heterologous DnaK in E. coli did not promote folding of the former. However, a combination of supplementary GroEL plus DnaK improved folding of PfAdoMetDC. These findings demonstrated that the SBD of PfHsp70-1 regulates several functional features of the protein and that this molecular chaperone is tailored to facilitate folding of plasmodial proteins.
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Affiliation(s)
- Charity Mekgwa Lebepe
- Department of Biochemistry, School of Mathematical & Natural Sciences, University of Venda, Thohoyandou 0950, South Africa; (C.M.L.); (P.R.M.); (T.Z.)
| | - Pearl Rutendo Matambanadzo
- Department of Biochemistry, School of Mathematical & Natural Sciences, University of Venda, Thohoyandou 0950, South Africa; (C.M.L.); (P.R.M.); (T.Z.)
| | - Xolani Henry Makhoba
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria 0028, South Africa;
| | - Ikechukwu Achilonu
- Protein Structure-Function Research Unit, School of Molecular and Cell Biology, University of the Witwatersrand, Johannesburg 2050, South Africa;
| | - Tawanda Zininga
- Department of Biochemistry, School of Mathematical & Natural Sciences, University of Venda, Thohoyandou 0950, South Africa; (C.M.L.); (P.R.M.); (T.Z.)
- Department of Biochemistry, Stellenbosch University, Stellenbosch 7602, South Africa
| | - Addmore Shonhai
- Department of Biochemistry, School of Mathematical & Natural Sciences, University of Venda, Thohoyandou 0950, South Africa; (C.M.L.); (P.R.M.); (T.Z.)
- Correspondence:
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Use of a Chimeric Hsp70 to Enhance the Quality of Recombinant Plasmodium falciparum S-Adenosylmethionine Decarboxylase Protein Produced in Escherichia coli. PLoS One 2016; 11:e0152626. [PMID: 27031344 PMCID: PMC4816425 DOI: 10.1371/journal.pone.0152626] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 03/16/2016] [Indexed: 01/22/2023] Open
Abstract
S-adenosylmethionine decarboxylase (PfAdoMetDC) from Plasmodium falciparum is a prospective antimalarial drug target. The production of recombinant PfAdoMetDC for biochemical validation as a drug target is important. The production of PfAdoMetDC in Escherichia coli has been reported to result in unsatisfactory yields and poor quality product. The co-expression of recombinant proteins with molecular chaperones has been proposed as one way to improve the production of the former in E. coli. E. coli heat shock proteins DnaK, GroEL-GroES and DnaJ have previously been used to enhance production of some recombinant proteins. However, the outcomes were inconsistent. An Hsp70 chimeric protein, KPf, which is made up of the ATPase domain of E. coli DnaK and the substrate binding domain of P. falciparum Hsp70 (PfHsp70) has been previously shown to exhibit chaperone function when it was expressed in E. coli cells whose resident Hsp70 (DnaK) function was impaired. We proposed that because of its domain constitution, KPf would most likely be recognised by E. coli Hsp70 co-chaperones. Furthermore, because it possesses a substrate binding domain of plasmodial origin, KPf would be primed to recognise recombinant PfAdoMetDC expressed in E. coli. First, using site-directed mutagenesis, followed by complementation assays, we established that KPf with a mutation in the hydrophobic residue located in its substrate binding cavity was functionally compromised. We further co-expressed PfAdoMetDC with KPf, PfHsp70 and DnaK in E. coli cells either in the absence or presence of over-expressed GroEL-GroES chaperonin. The folded and functional status of the produced PfAdoMetDC was assessed using limited proteolysis and enzyme assays. PfAdoMetDC co-expressed with KPf and PfHsp70 exhibited improved activity compared to protein co-expressed with over-expressed DnaK. Our findings suggest that chimeric KPf may be an ideal Hsp70 co-expression partner for the production of recombinant plasmodial proteins in E. coli.
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A Putative Non-Canonical Ras-Like GTPase from P. falciparum: Chemical Properties and Characterization of the Protein. PLoS One 2015; 10:e0140994. [PMID: 26540393 PMCID: PMC4634863 DOI: 10.1371/journal.pone.0140994] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 10/02/2015] [Indexed: 12/16/2022] Open
Abstract
During its development the malaria parasite P. falciparum has to adapt to various different environmental contexts. Key cellular mechanisms involving G-protein coupled signal transduction chains are assumed to act at these interfaces. Heterotrimeric G-proteins are absent in Plasmodium. We here describe the first cloning and expression of a putative, non-canonical Ras-like G protein (acronym PfG) from Plasmodium. PfG reveals an open reading frame of 2736 bp encoding a protein of 912 amino acids with a theoretical pI of 8.68 and a molecular weight of 108.57 kDa. Transcript levels and expression are significantly increased in the erythrocytic phase in particular during schizont and gametocyte formation. Most notably, PfG has GTP binding capacity and GTPase activity due to an EngA2 domain present in small Ras-like GTPases in a variety of Bacillus species and Mycobacteria. By contrast, plasmodial PfG is divergent from any human alpha-subunit. PfG was expressed in E. coli as a histidine-tagged fusion protein and was stable only for 3.5 hours. Purification was only possible under native conditions by Nickel-chelate chromatography and subsequent separation by Blue Native PAGE. Binding of a fluorescent GTP analogue BODIPY® FL guanosine 5’O-(thiotriphosphate) was determined by fluorescence emission. Mastoparan stimulated GTP binding in the presence of Mg2+. GTPase activity was determined colorimetrically. Activity expressed as absolute fluorescence was 50% higher for the human paralogue than the activity of the parasitic enzyme. The PfG protein is expressed in the erythrocytic stages and binds GTP after immunoprecipitation. Immunofluorescence using specific antiserum suggests that PfG localizes to the parasite cytosol. The current data suggest that the putitative, Ras-like G-protein might be involved in a non-canonical signaling pathway in Plasmodium. Research on the function of PfG with respect to pathogenesis and antimalarial chemotherapy is currently under way.
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Vitamin B6-dependent enzymes in the human malaria parasite Plasmodium falciparum: a druggable target? BIOMED RESEARCH INTERNATIONAL 2014; 2014:108516. [PMID: 24524072 PMCID: PMC3912857 DOI: 10.1155/2014/108516] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Revised: 10/24/2013] [Accepted: 11/28/2013] [Indexed: 11/17/2022]
Abstract
Malaria is a deadly infectious disease which affects millions of people each year in tropical regions. There is no effective vaccine available and the treatment is based on drugs which are currently facing an emergence of drug resistance and in this sense the search for new drug targets is indispensable. It is well established that vitamin biosynthetic pathways, such as the vitamin B6 de novo synthesis present in Plasmodium, are excellent drug targets. The active form of vitamin B6, pyridoxal 5-phosphate, is, besides its antioxidative properties, a cofactor for a variety of essential enzymes present in the malaria parasite which includes the ornithine decarboxylase (ODC, synthesis of polyamines), the aspartate aminotransferase (AspAT, involved in the protein biosynthesis), and the serine hydroxymethyltransferase (SHMT, a key enzyme within the folate metabolism).
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le Roux D, Burger PB, Niemand J, Grobler A, Urbán P, Fernàndez-Busquets X, Barker RH, Serrano AE, I Louw A, Birkholtz LM. Novel S-adenosyl-L-methionine decarboxylase inhibitors as potent antiproliferative agents against intraerythrocytic Plasmodium falciparum parasites. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2013; 4:28-36. [PMID: 24596666 PMCID: PMC3940083 DOI: 10.1016/j.ijpddr.2013.11.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Revised: 11/19/2013] [Accepted: 11/20/2013] [Indexed: 12/31/2022]
Abstract
S-adenosyl-l-methionine decarboxylase (AdoMetDC) in the polyamine biosynthesis pathway has been identified as a suitable drug target in Plasmodium falciparum parasites, which causes the most lethal form of malaria. Derivatives of an irreversible inhibitor of this enzyme, 5'-{[(Z)-4-amino-2-butenyl]methylamino}-5'-deoxyadenosine (MDL73811), have been developed with improved pharmacokinetic profiles and activity against related parasites, Trypanosoma brucei. Here, these derivatives were assayed for inhibition of AdoMetDC from P. falciparum parasites and the methylated derivative, 8-methyl-5'-{[(Z)-4-aminobut-2-enyl]methylamino}-5'-deoxyadenosine (Genz-644131) was shown to be the most active. The in vitro efficacy of Genz-644131 was markedly increased by nanoencapsulation in immunoliposomes, which specifically targeted intraerythrocytic P. falciparum parasites.
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Affiliation(s)
- Dina le Roux
- Department of Biochemistry, Centre for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Pieter B Burger
- Department of Biochemistry, Centre for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Jandeli Niemand
- Department of Biochemistry, Centre for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Anne Grobler
- DST/NWU Preclinical Drug Development Platform, North-West University, Potchefstroom 2531, South Africa
| | - Patricia Urbán
- Nanobioengineering Group, Institute for Bioengineering of Catalonia, Baldiri Reixac 10-12, Barcelona E08028, Spain ; Barcelona Centre for International Health Research (CRESIB), Hospital Clínic-Universitat de Barcelona, Rosselló 149-153, Barcelona E08036, Spain ; Biomolecular Interactions Team, Nanoscience and Nanotechnology Institute (IN2UB), University of Barcelona, Martí i Franquès 1, Barcelona E08028, Spain
| | - Xavier Fernàndez-Busquets
- Nanobioengineering Group, Institute for Bioengineering of Catalonia, Baldiri Reixac 10-12, Barcelona E08028, Spain ; Barcelona Centre for International Health Research (CRESIB), Hospital Clínic-Universitat de Barcelona, Rosselló 149-153, Barcelona E08036, Spain ; Biomolecular Interactions Team, Nanoscience and Nanotechnology Institute (IN2UB), University of Barcelona, Martí i Franquès 1, Barcelona E08028, Spain
| | - Robert H Barker
- Genzyme Corporation, 153 Second Avenue, Waltham, MA 02451, USA
| | - Adelfa E Serrano
- University of Puerto Rico-School of Medicine, Department of Microbiology and Medical Zoology, P.O. Box 365067, San Juan PR 00936-5067, Puerto Rico
| | - Abraham I Louw
- Department of Biochemistry, Centre for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Lyn-Marie Birkholtz
- Department of Biochemistry, Centre for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
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Sanz S, Bandini G, Ospina D, Bernabeu M, Mariño K, Fernández-Becerra C, Izquierdo L. Biosynthesis of GDP-fucose and other sugar nucleotides in the blood stages of Plasmodium falciparum. J Biol Chem 2013; 288:16506-16517. [PMID: 23615908 DOI: 10.1074/jbc.m112.439828] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Carbohydrate structures play important roles in many biological processes, including cell adhesion, cell-cell communication, and host-pathogen interactions. Sugar nucleotides are activated forms of sugars used by the cell as donors for most glycosylation reactions. Using a liquid chromatography-tandem mass spectrometry-based method, we identified and quantified the pools of UDP-glucose, UDP-galactose, UDP-N-acetylglucosamine, GDP-mannose, and GDP-fucose in Plasmodium falciparum intraerythrocytic life stages. We assembled these data with the in silico functional reconstruction of the parasite metabolic pathways obtained from the P. falciparum annotated genome, exposing new active biosynthetic routes crucial for further glycosylation reactions. Fucose is a sugar present in glycoconjugates often associated with recognition and adhesion events. Thus, the GDP-fucose precursor is essential in a wide variety of organisms. P. falciparum presents homologues of GDP-mannose 4,6-dehydratase and GDP-L-fucose synthase enzymes that are active in vitro, indicating that most GDP-fucose is formed by a de novo pathway that involves the bioconversion of GDP-mannose. Homologues for enzymes involved in a fucose salvage pathway are apparently absent in the P. falciparum genome. This is in agreement with in vivo metabolic labeling experiments showing that fucose is not significantly incorporated by the parasite. Fluorescence microscopy of epitope-tagged versions of P. falciparum GDP-mannose 4,6-dehydratase and GDP-L-fucose synthase expressed in transgenic 3D7 parasites shows that these enzymes localize in the cytoplasm of P. falciparum during the intraerythrocytic developmental cycle. Although the function of fucose in the parasite is not known, the presence of GDP-fucose suggests that the metabolite may be used for further fucosylation reactions.
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Affiliation(s)
- Sílvia Sanz
- Barcelona Centre for International Health Research, Hospital Clínic-Universitat de Barcelona, CEK, 1a Planta, Rosselló 149-153, 08036, Barcelona, Spain
| | - Giulia Bandini
- College of Life Sciences, University of Dundee, Division of Biological Chemistry and Drug Discovery, Wellcome Trust Biocentre, Dundee DD15EH, Scotland, United Kingdom
| | - Diego Ospina
- Barcelona Centre for International Health Research, Hospital Clínic-Universitat de Barcelona, CEK, 1a Planta, Rosselló 149-153, 08036, Barcelona, Spain
| | - Maria Bernabeu
- Barcelona Centre for International Health Research, Hospital Clínic-Universitat de Barcelona, CEK, 1a Planta, Rosselló 149-153, 08036, Barcelona, Spain
| | - Karina Mariño
- College of Life Sciences, University of Dundee, Division of Biological Chemistry and Drug Discovery, Wellcome Trust Biocentre, Dundee DD15EH, Scotland, United Kingdom
| | - Carmen Fernández-Becerra
- Barcelona Centre for International Health Research, Hospital Clínic-Universitat de Barcelona, CEK, 1a Planta, Rosselló 149-153, 08036, Barcelona, Spain
| | - Luis Izquierdo
- Barcelona Centre for International Health Research, Hospital Clínic-Universitat de Barcelona, CEK, 1a Planta, Rosselló 149-153, 08036, Barcelona, Spain.
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Niemand J, Louw AI, Birkholtz L, Kirk K. Polyamine uptake by the intraerythrocytic malaria parasite, Plasmodium falciparum. Int J Parasitol 2012; 42:921-9. [PMID: 22878129 DOI: 10.1016/j.ijpara.2012.07.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Revised: 07/21/2012] [Accepted: 07/23/2012] [Indexed: 11/26/2022]
Abstract
Polyamines and the enzymes involved in their biosynthesis are present at high levels in rapidly proliferating cells, including cancer cells and protozoan parasites. Inhibition of polyamine biosynthesis in asexual blood-stage malaria parasites causes cytostatic arrest of parasite development under in vitro conditions, but does not cure infections in vivo. This may be due to replenishment of the parasite's intracellular polyamine pool via salvage of exogenous polyamines from the host. However, the mechanism(s) of polyamine uptake by the intraerythrocytic parasite are not well understood. In this study, the uptake of the polyamines, putrescine and spermidine, into Plasmodium falciparum parasites functionally isolated from their host erythrocyte was investigated using radioisotope flux techniques. Both putrescine and spermidine were taken up into isolated parasites via a temperature-dependent process that showed cross-competition between different polyamines. There was also some inhibition of polyamine uptake by basic amino acids. Inhibition of polyamine biosynthesis led to an increase in the total amount of putrescine and spermidine taken up from the extracellular medium. The uptake of putrescine and spermidine by isolated parasites was independent of extracellular Na(+) but increased with increasing external pH. Uptake also showed a marked dependence on the parasite's membrane potential, decreasing with membrane depolarization and increasing with membrane hyperpolarization. The data are consistent with polyamines being taken up into the parasite via an electrogenic uptake process, energised by the parasite's inwardly negative membrane potential.
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Affiliation(s)
- J Niemand
- Department of Biochemistry, Faculty of Natural and Agricultural Sciences, University of Pretoria, Hatfield 0028, South Africa
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