7 results on '"Kenthirapalan S"'
Search Results
2. Vital and dispensable roles of Plasmodium multidrug resistance transporters during blood- and mosquito-stage development
- Author
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Rijpma, S.R., Velden, M. van der, Annoura, T., Matz, J.M., Kenthirapalan, S., Kooij, T.W.A., Matuschewski, K., Gemert, G.J. van, Vegte-Bolmer, M. van de, Siebelink-Stoter, R., Graumans, W., Ramesar, J., Klop, O., Russel, F.G.M., Sauerwein, R.W., Janse, C.J., Franke-Fayard, B.M., and Koenderink, J.B.
- Subjects
Renal disorders Radboud Institute for Molecular Life Sciences [Radboudumc 11] ,lnfectious Diseases and Global Health Radboud Institute for Health Sciences [Radboudumc 4] ,parasitic diseases ,lnfectious Diseases and Global Health Radboud Institute for Molecular Life Sciences [Radboudumc 4] - Abstract
Contains fulltext : 170840.pdf (Publisher’s version ) (Closed access) Multidrug resistance (MDR) proteins belong to the B subfamily of the ATP Binding Cassette (ABC) transporters, which export a wide range of compounds including pharmaceuticals. In this study, we used reverse genetics to study the role of all seven Plasmodium MDR proteins during the life cycle of malaria parasites. Four P. berghei genes (encoding MDR1, 4, 6 and 7) were refractory to deletion, indicating a vital role during blood stage multiplication and validating them as potential targets for antimalarial drugs. Mutants lacking expression of MDR2, MDR3 and MDR5 were generated in both P. berghei and P. falciparum, indicating a dispensable role for blood stage development. Whereas P. berghei mutants lacking MDR3 and MDR5 had a reduced blood stage multiplication in vivo, blood stage growth of P. falciparum mutants in vitro was not significantly different. Oocyst maturation and sporozoite formation in Plasmodium mutants lacking MDR2 or MDR5 was reduced. Sporozoites of these P. berghei mutants were capable of infecting mice and life cycle completion, indicating the absence of vital roles during liver stage development. Our results demonstrate vital and dispensable roles of MDR proteins during blood stages and an important function in sporogony for MDR2 and MDR5 in both Plasmodium species.
- Published
- 2016
3. Copper-transporting ATPase is important for malaria parasite fertility
- Author
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Kenthirapalan, S., Waters, A.P., Matuschewski, K., and Kooij, T.W.A.
- Subjects
parasitic diseases ,lnfectious Diseases and Global Health Radboud Institute for Molecular Life Sciences [Radboudumc 4] - Abstract
Item does not contain fulltext Homeostasis of the trace element copper is essential to all eukaryotic life. Copper serves as a cofactor in metalloenzymes and catalyses electron transfer reactions as well as the generation of potentially toxic reactive oxygen species. Here, we describe the functional characterization of an evolutionarily highly conserved, predicted copper-transporting P-type ATPase (CuTP) in the murine malaria model parasite Plasmodium berghei. Live imaging of a parasite line expressing a fluorescently tagged CuTP demonstrated that CuTP is predominantly located in vesicular bodies of the parasite. A P. berghei loss-of-function mutant line was readily obtained and showed no apparent defect in in vivo blood stage growth. Parasite transmission through the mosquito vector was severely affected, but not entirely abolished. We show that male and female gametocytes are abundant in cutp(-) parasites, but activation of male microgametes and exflagellation were strongly impaired. This specific defect could be mimicked by addition of the copper chelator neocuproine to wild-type gametocytes. A cross-fertilization assay demonstrated that female fertility was also severely abrogated. In conclusion, we provide experimental genetic and pharmacological evidence that a healthy copper homeostasis is critical to malaria parasite fertility of both genders of gametocyte and, hence, to transmission to the mosquito vector.
- Published
- 2014
4. Vital and dispensable roles of Plasmodium multidrug resistance transporters during blood- and mosquito-stage development.
- Author
-
Rijpma SR, van der Velden M, Annoura T, Matz JM, Kenthirapalan S, Kooij TW, Matuschewski K, van Gemert GJ, van de Vegte-Bolmer M, Siebelink-Stoter R, Graumans W, Ramesar J, Klop O, Russel FG, Sauerwein RW, Janse CJ, Franke-Fayard BM, and Koenderink JB
- Subjects
- Animals, Antimalarials pharmacology, Drug Resistance, Multiple, Female, Life Cycle Stages, Malaria parasitology, Malaria, Falciparum parasitology, Male, Membrane Transport Proteins metabolism, Mice, Mice, Inbred BALB C, Mice, Inbred C57BL, Multidrug Resistance-Associated Proteins genetics, Oocytes metabolism, Plasmodium berghei genetics, Plasmodium berghei growth & development, Plasmodium falciparum genetics, Plasmodium falciparum growth & development, Sporozoites metabolism, Culicidae parasitology, Multidrug Resistance-Associated Proteins metabolism, Plasmodium berghei drug effects, Plasmodium berghei metabolism, Plasmodium falciparum drug effects, Plasmodium falciparum metabolism
- Abstract
Multidrug resistance (MDR) proteins belong to the B subfamily of the ATP Binding Cassette (ABC) transporters, which export a wide range of compounds including pharmaceuticals. In this study, we used reverse genetics to study the role of all seven Plasmodium MDR proteins during the life cycle of malaria parasites. Four P. berghei genes (encoding MDR1, 4, 6 and 7) were refractory to deletion, indicating a vital role during blood stage multiplication and validating them as potential targets for antimalarial drugs. Mutants lacking expression of MDR2, MDR3 and MDR5 were generated in both P. berghei and P. falciparum, indicating a dispensable role for blood stage development. Whereas P. berghei mutants lacking MDR3 and MDR5 had a reduced blood stage multiplication in vivo, blood stage growth of P. falciparum mutants in vitro was not significantly different. Oocyst maturation and sporozoite formation in Plasmodium mutants lacking MDR2 or MDR5 was reduced. Sporozoites of these P. berghei mutants were capable of infecting mice and life cycle completion, indicating the absence of vital roles during liver stage development. Our results demonstrate vital and dispensable roles of MDR proteins during blood stages and an important function in sporogony for MDR2 and MDR5 in both Plasmodium species., (© 2016 John Wiley & Sons Ltd.)
- Published
- 2016
- Full Text
- View/download PDF
5. Functional profiles of orphan membrane transporters in the life cycle of the malaria parasite.
- Author
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Kenthirapalan S, Waters AP, Matuschewski K, and Kooij TW
- Subjects
- Animals, Anopheles, Female, Life Cycle Stages, Male, Membrane Transport Proteins genetics, Mice, Mice, Inbred C57BL, Plasmodium berghei genetics, Membrane Transport Proteins metabolism, Plasmodium berghei metabolism
- Abstract
Assigning function to orphan membrane transport proteins and prioritizing candidates for detailed biochemical characterization remain fundamental challenges and are particularly important for medically relevant pathogens, such as malaria parasites. Here we present a comprehensive genetic analysis of 35 orphan transport proteins of Plasmodium berghei during its life cycle in mice and Anopheles mosquitoes. Six genes, including four candidate aminophospholipid transporters, are refractory to gene deletion, indicative of essential functions. We generate and phenotypically characterize 29 mutant strains with deletions of individual transporter genes. Whereas seven genes appear to be dispensable under the experimental conditions tested, deletion of any of the 22 other genes leads to specific defects in life cycle progression in vivo and/or host transition. Our study provides growing support for a potential link between heavy metal homeostasis and host switching and reveals potential targets for rational design of new intervention strategies against malaria.
- Published
- 2016
- Full Text
- View/download PDF
6. Copper-transporting ATPase is important for malaria parasite fertility.
- Author
-
Kenthirapalan S, Waters AP, Matuschewski K, and Kooij TW
- Subjects
- Animals, Copper-Transporting ATPases, Disease Models, Animal, Female, Fertility, Malaria metabolism, Male, Mice, Mice, Inbred C57BL, Mutation, Phenanthrolines pharmacology, Plasmodium berghei genetics, Plasmodium berghei growth & development, Plasmodium berghei pathogenicity, Adenosine Triphosphatases metabolism, Cation Transport Proteins metabolism, Copper metabolism, Culicidae parasitology, Malaria parasitology, Plasmodium berghei enzymology, Protozoan Proteins metabolism
- Abstract
Homeostasis of the trace element copper is essential to all eukaryotic life. Copper serves as a cofactor in metalloenzymes and catalyses electron transfer reactions as well as the generation of potentially toxic reactive oxygen species. Here, we describe the functional characterization of an evolutionarily highly conserved, predicted copper-transporting P-type ATPase (CuTP) in the murine malaria model parasite Plasmodium berghei. Live imaging of a parasite line expressing a fluorescently tagged CuTP demonstrated that CuTP is predominantly located in vesicular bodies of the parasite. A P. berghei loss-of-function mutant line was readily obtained and showed no apparent defect in in vivo blood stage growth. Parasite transmission through the mosquito vector was severely affected, but not entirely abolished. We show that male and female gametocytes are abundant in cutp(-) parasites, but activation of male microgametes and exflagellation were strongly impaired. This specific defect could be mimicked by addition of the copper chelator neocuproine to wild-type gametocytes. A cross-fertilization assay demonstrated that female fertility was also severely abrogated. In conclusion, we provide experimental genetic and pharmacological evidence that a healthy copper homeostasis is critical to malaria parasite fertility of both genders of gametocyte and, hence, to transmission to the mosquito vector., (© 2013 The Authors. Molecular Microbiology published by John Wiley & Sons Ltd.)
- Published
- 2014
- Full Text
- View/download PDF
7. Reprogramming a module of the 6-deoxyerythronolide B synthase for iterative chain elongation.
- Author
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Kapur S, Lowry B, Yuzawa S, Kenthirapalan S, Chen AY, Cane DE, and Khosla C
- Subjects
- Acyl Carrier Protein metabolism, Amino Acid Sequence, Biocatalysis, Models, Molecular, Molecular Sequence Data, Polyketides chemistry, Protein Engineering, Protein Transport, Substrate Specificity, Polyketide Synthases chemistry, Polyketide Synthases metabolism, Polyketides metabolism
- Abstract
Multimodular polyketide synthases (PKSs) have an assembly line architecture in which a set of protein domains, known as a module, participates in one round of polyketide chain elongation and associated chemical modifications, after which the growing chain is translocated to the next PKS module. The ability to rationally reprogram these assembly lines to enable efficient synthesis of new polyketide antibiotics has been a long-standing goal in natural products biosynthesis. We have identified a ratchet mechanism that can explain the observed unidirectional translocation of the growing polyketide chain along the 6-deoxyerythronolide B synthase. As a test of this model, module 3 of the 6-deoxyerythronolide B synthase has been reengineered to catalyze two successive rounds of chain elongation. Our results suggest that high selectivity has been evolutionarily programmed at three types of protein-protein interfaces that are present repetitively along naturally occurring PKS assembly lines.
- Published
- 2012
- Full Text
- View/download PDF
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