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Banerjee C, Nag S, Goyal M, Saha D, Siddiqui AA, Mazumder S, Debsharma S, Pramanik S, Bandyopadhyay U. Nuclease activity of Plasmodium falciparum Alba family protein PfAlba3. Cell Rep 2023; 42:112292. [PMID: 36947546 DOI: 10.1016/j.celrep.2023.112292] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 01/06/2023] [Accepted: 03/06/2023] [Indexed: 03/23/2023] Open
Abstract
Plasmodium falciparum Alba domain-containing protein Alba3 (PfAlba3) is ubiquitously expressed in intra-erythrocytic stages of Plasmodium falciparum, but the function of this protein is not yet established. Here, we report an apurinic/apyrimidinic site-driven intrinsic nuclease activity of PfAlba3 assisted by divalent metal ions. Surface plasmon resonance and atomic force microscopy confirm sequence non-specific DNA binding by PfAlba3. Upon binding, PfAlba3 cleaves double-stranded DNA (dsDNA) hydrolytically. Mutational studies coupled with mass spectrometric analysis indicate that K23 is the essential residue in modulating the binding to DNA through acetylation-deacetylation. We further demonstrate that PfSir2a interacts and deacetylates K23-acetylated PfAlba3 in favoring DNA binding. Hence, K23 serves as a putative molecular switch regulating the nuclease activity of PfAlba3. Thus, the nuclease activity of PfAlba3, along with its apurinic/apyrimidinic (AP) endonuclease feature identified in this study, indicates a role of PfAlba3 in DNA-damage response that may have a far-reaching consequence in Plasmodium pathogenicity.
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Affiliation(s)
- Chinmoy Banerjee
- Division of Infectious Diseases and Immunology, CSIR-Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Jadavpur, Kolkata, West Bengal 700032, India
| | - Shiladitya Nag
- Division of Infectious Diseases and Immunology, CSIR-Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Jadavpur, Kolkata, West Bengal 700032, India
| | - Manish Goyal
- Division of Infectious Diseases and Immunology, CSIR-Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Jadavpur, Kolkata, West Bengal 700032, India
| | - Debanjan Saha
- Division of Infectious Diseases and Immunology, CSIR-Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Jadavpur, Kolkata, West Bengal 700032, India
| | - Asim Azhar Siddiqui
- Division of Infectious Diseases and Immunology, CSIR-Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Jadavpur, Kolkata, West Bengal 700032, India
| | - Somnath Mazumder
- Division of Infectious Diseases and Immunology, CSIR-Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Jadavpur, Kolkata, West Bengal 700032, India
| | - Subhashis Debsharma
- Division of Infectious Diseases and Immunology, CSIR-Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Jadavpur, Kolkata, West Bengal 700032, India
| | - Saikat Pramanik
- Division of Infectious Diseases and Immunology, CSIR-Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Jadavpur, Kolkata, West Bengal 700032, India
| | - Uday Bandyopadhyay
- Division of Infectious Diseases and Immunology, CSIR-Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Jadavpur, Kolkata, West Bengal 700032, India; Division of Molecular Medicine, Bose Institute, EN 80, Sector V, Bidhan Nagar Kolkata, 700091, West Bengal, India.
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Rattaprasert P, Suntornthiticharoen P, Limudomporn P, Thima K, Chavalitshewinkoon-Petmitr P. Inhibitory effects of anthracyclines on partially purified 5'-3' DNA helicase of Plasmodium falciparum. Malar J 2022; 21:216. [PMID: 35821133 PMCID: PMC9275250 DOI: 10.1186/s12936-022-04238-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 07/04/2022] [Indexed: 11/29/2022] Open
Abstract
Background Plasmodium falciparum has been becoming resistant to the currently used anti-malarial drugs. Searching for new drug targets is urgently needed for anti-malarial development. DNA helicases separating double-stranded DNA into single-stranded DNA intermediates are essential in nearly all DNA metabolic transactions, thus they may act as a candidate for new drug targets against malarial parasites. Methods In this study, a P. falciparum 5′ to 3′ DNA helicase (PfDH-B) was partially purified from the crude extract of chloroquine- and pyrimethamine-resistant P. falciparum strain K1, by ammonium sulfate precipitation and three chromatographic procedures. DNA helicase activity of partially purified PfDH-B was examined by measuring its ability to unwind 32P-labelled partial duplex DNA. The directionality of PfDH-B was determined, and substrate preference was tested by using various substrates. Inhibitory effects of DNA intercalators such as anthracycline antibiotics on PfDH-B unwinding activity and parasite growth were investigated. Results The native PfDH-B was partially purified with a specific activity of 4150 units/mg. The PfDH-B could unwind M13-17-mer, M13-31-mer with hanging tail at 3′ or 5′ end and a linear substrate with 3′ end hanging tail but not blunt-ended duplex DNA, and did not need a fork-like substrate. Anthracyclines including aclarubicin, daunorubicin, doxorubicin, and nogalamycin inhibited the unwinding activity of PfDH-B with an IC50 value of 4.0, 7.5, 3.6, and 3.1 µM, respectively. Nogalamycin was the most effective inhibitor on PfDH-B unwinding activity and parasite growth (IC50 = 0.1 ± 0.002 µM). Conclusion Partial purification and characterization of 5′–3′ DNA helicase of P. falciparum was successfully performed. The partially purified PfDH-B does not need a fork-like substrate structure found in P. falciparum 3′ to 5′ DNA helicase (PfDH-A). Interestingly, nogalamycin was the most potent anthracycline inhibitor for PfDH-B helicase activity and parasite growth in culture. Further studies are needed to search for more potent but less cytotoxic inhibitors targeting P. falciparum DNA helicase in the future.
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Affiliation(s)
- Pongruj Rattaprasert
- Department of Protozoology, Faculty of Tropical Medicine, Mahidol University, Ratchawithi Road, Bangkok, 10400, Thailand
| | | | - Paviga Limudomporn
- Department of Zoology, Faculty of Science, Kasetsart University, Bangkok, 10900, Thailand
| | - Kanthinich Thima
- Department of Protozoology, Faculty of Tropical Medicine, Mahidol University, Ratchawithi Road, Bangkok, 10400, Thailand
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Plasmodium Ape1 is a multifunctional enzyme in mitochondrial base excision repair and is required for efficient transition from liver to blood stage infection. DNA Repair (Amst) 2021; 101:103098. [PMID: 33743509 DOI: 10.1016/j.dnarep.2021.103098] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 03/01/2021] [Accepted: 03/09/2021] [Indexed: 02/02/2023]
Abstract
The malaria parasite has a single mitochondrion which carries multiple tandem repeats of its 6 kb genome encoding three proteins of the electron transport chain. There is little information about DNA repair mechanisms for mitochondrial genome maintenance in Plasmodium spp. Of the two AP-endonucleases of the BER pathway encoded in the parasite nuclear genome, the EndoIV homolog PfApn1 has been identified as a mitochondrial protein with restricted functions. We explored the targeting and biochemical properties of the ExoIII homolog PfApe1. PfApe1 localized in the mitochondrion and exhibited AP-site cleavage, 3'-5' exonuclease, 3'-phosphatase, nucleotide incision repair (NIR) and RNA cleavage activities indicating a wider functional role than PfApn1. The parasite enzyme differed from human APE1 in possessing a large, disordered N-terminal extension. Molecular modelling revealed conservation of structural domains but variations in DNA-interacting residues and an insertion in the α-8 loop suggested differences with APE1. Unlike APE1, where AP-site cleavage and NIR activities could be mutually exclusive based on pH and Mg2+ ion concentration, PfApe1 was optimally active under similar conditions suggesting that it can function both as an AP-endonuclease in BER and directly cleave damaged bases in NIR under similar physiological conditions. To investigate the role of Ape1 in malaria life cycle, we disrupted the gene by double-cross-over homologous recombination. Ape1 knockout (KO) P. berghei parasites showed normal development of blood and mosquito stages. However, inoculation of mice with Ape1 KO salivary gland sporozoites revealed a reduced capacity to initiate blood stage infection. Ape1 KO parasites underwent normal liver stage development until merozoites egressed from hepatocytes. Our results indicated that the delay in pre-patent period was due to the inability of Ape1 KO merosomes to infect erythrocytes efficiently.
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Tiwari A, Kuldeep J, Siddiqi MI, Habib S. Plasmodium falciparumApn1 homolog is a mitochondrial base excision repair protein with restricted enzymatic functions. FEBS J 2019; 287:589-606. [DOI: 10.1111/febs.15032] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 06/18/2019] [Accepted: 08/02/2019] [Indexed: 01/14/2023]
Affiliation(s)
- Anupama Tiwari
- Division of Molecular and Structural Biology CSIR‐Central Drug Research Institute Lucknow India
| | - Jitendra Kuldeep
- Division of Molecular and Structural Biology CSIR‐Central Drug Research Institute Lucknow India
| | - Mohammad Imran Siddiqi
- Division of Molecular and Structural Biology CSIR‐Central Drug Research Institute Lucknow India
| | - Saman Habib
- Division of Molecular and Structural Biology CSIR‐Central Drug Research Institute Lucknow India
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Tuteja R. Unraveling the importance of the malaria parasite helicases. FEBS J 2017; 284:2592-2603. [DOI: 10.1111/febs.14109] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 05/04/2017] [Accepted: 05/10/2017] [Indexed: 12/27/2022]
Affiliation(s)
- Renu Tuteja
- Parasite Biology Group; International Centre for Genetic Engineering and Biotechnology; New Delhi India
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Tarique M, Chauhan M, Tuteja R. ATPase activity of Plasmodium falciparum MLH is inhibited by DNA-interacting ligands and dsRNAs of MLH along with UvrD curtail malaria parasite growth. PROTOPLASMA 2017; 254:1295-1305. [PMID: 27624787 DOI: 10.1007/s00709-016-1021-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 09/01/2016] [Indexed: 06/06/2023]
Abstract
Malaria caused by Plasmodium falciparum is the major disease burden all over the world. Recently, the situation has deteriorated because the malarial parasites are becoming progressively more resistant to numerous commonly used antimalarial drugs. Thus, there is a critical requirement to find other means to restrict and eliminate malaria. The mismatch repair (MMR) machinery of parasite is quite unique in several ways, and it can be exploited for finding new drug targets. MutL homolog (MLH) is one of the major components of MMR machinery, and along with UvrD, it helps in unwinding the DNA. We have screened several DNA-interacting ligands for their effect on intrinsic ATPase activity of PfMLH protein. This screening suggested that several ligands such as daunorubicin, etoposide, ethidium bromide, netropsin, and nogalamycin are inhibitors of the ATPase activity of PfMLH, and their apparent IC50 values range from 2.1 to 9.35 μM. In the presence of nogalamycin and netropsin, the effect was significant because in their presence, the V max value dropped from 1.024 μM of hydrolyzed ATP/min to 0.596 and 0.643 μM of hydrolyzed ATP/min, respectively. The effect of double-stranded RNAs of PfMLH and PfUvrD on growth of P. falciparum 3D7 strain was studied. The parasite growth was significantly inhibited suggesting that these components belonging to MMR pathway are crucial for the survival of the parasite.
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Affiliation(s)
- Mohammed Tarique
- Parasite Biology Group, International Centre for Genetic Engineering and Biotechnology, P. O. Box 10504, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Manish Chauhan
- Parasite Biology Group, International Centre for Genetic Engineering and Biotechnology, P. O. Box 10504, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Renu Tuteja
- Parasite Biology Group, International Centre for Genetic Engineering and Biotechnology, P. O. Box 10504, Aruna Asaf Ali Marg, New Delhi, 110067, India.
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A novel Pfs38 protein complex on the surface of Plasmodium falciparum blood-stage merozoites. Malar J 2017; 16:79. [PMID: 28202027 PMCID: PMC5312596 DOI: 10.1186/s12936-017-1716-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 01/28/2017] [Indexed: 11/10/2022] Open
Abstract
Background The Plasmodium genome encodes for a number of 6-Cys proteins that contain a module of six cysteine residues forming three intramolecular disulphide bonds. These proteins have been well characterized at transmission as well as hepatic stages of the parasite life cycle. In the present study, a large complex of 6-Cys proteins: Pfs41, Pfs38 and Pfs12 and three other merozoite surface proteins: Glutamate-rich protein (GLURP), SERA5 and MSP-1 were identified on the Plasmodium falciparum merozoite surface. Methods Recombinant 6-cys proteins i.e. Pfs38, Pfs12, Pfs41 as well as PfMSP-165 were expressed and purified using Escherichia coli expression system and antibodies were raised against each of these proteins. These antibodies were used to immunoprecipitate the native proteins and their associated partners from parasite lysate. ELISA, Far western, surface plasmon resonance and glycerol density gradient fractionation were carried out to confirm the respective interactions. Furthermore, erythrocyte binding assay with 6-cys proteins were undertaken to find out their possible role in host-parasite infection and seropositivity was assessed using Indian and Liberian sera. Results Immunoprecipitation of parasite-derived polypeptides, followed by LC–MS/MS analysis, identified a large Pfs38 complex comprising of 6-cys proteins: Pfs41, Pfs38, Pfs12 and other merozoite surface proteins: GLURP, SERA5 and MSP-1. The existence of such a complex was further corroborated by several protein–protein interaction tools, co-localization and co-sedimentation analysis. Pfs38 protein of Pfs38 complex binds to host red blood cells (RBCs) directly via glycophorin A as a receptor. Seroprevalence analysis showed that of the six antigens, prevalence varied from 40 to 99%, being generally highest for MSP-165 and GLURP proteins. Conclusions Together the data show the presence of a large Pfs38 protein-associated complex on the parasite surface which is involved in RBC binding. These results highlight the complex molecular interactions among the P. falciparum merozoite surface proteins and advocate the development of a multi-sub-unit malaria vaccine based on some of these protein complexes on merozoite surface. Electronic supplementary material The online version of this article (doi:10.1186/s12936-017-1716-0) contains supplementary material, which is available to authorized users.
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Tarique M, Ahmad M, Chauhan M, Tuteja R. Genome Wide In silico Analysis of the Mismatch Repair Components of Plasmodium falciparum and Their Comparison with Human Host. Front Microbiol 2017; 8:130. [PMID: 28232818 PMCID: PMC5298969 DOI: 10.3389/fmicb.2017.00130] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 01/18/2017] [Indexed: 12/28/2022] Open
Abstract
Malaria a major parasitic infection globally particularly in tropical and sub-tropical regions of the world is responsible for about 198 million cases and estimated deaths due to this disease are about 0.6 million. The emergence of drug resistance in the malaria parasite is alarming and it is necessary to understand its underlying cause and molecular mechanisms. It has been established that drug resistant malaria parasites have defective mismatch repair (MMR) therefore it is essential to study this pathway and its components in detail. Recently a number of non-synonymous Single Nucleotide Polymorphisms have been reported in genes involved in MMR pathways. PfMLH is an endonuclease essential to restore the MMR in drug resistant strains of Plasmodium falciparum. Considering all these facts about the role of MMR in emergence of drug resistant parasite, in this manuscript we report a genome wide analysis of the components of the MMR pathway such as MLH, Pms1, MSH2-1, MSH2-2, MSH6, and UvrD using in silico bioinformatics based approaches. The phylogenetic analysis revealed evolutionary closeness with the MMR components of various organisms. It is noteworthy that P. falciparum contains two homologs of MSH2, which are located on different chromosomes. The structural modeling of these components showed their similarity with the human/yeast MMR components. The docking studies reveal that PfUvrD and PfMLH interact with each other. The in silico identification of interacting partners of the major MMR components identified numerous P. falciparum specific proteins. In line with our previous studies the present study will also contribute significantly to understand the MMR pathway of malaria parasite.
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Affiliation(s)
- Mohammed Tarique
- Parasite Biology Group, International Centre for Genetic Engineering and Biotechnology New Delhi, India
| | - Moaz Ahmad
- Parasite Biology Group, International Centre for Genetic Engineering and Biotechnology New Delhi, India
| | - Manish Chauhan
- Parasite Biology Group, International Centre for Genetic Engineering and Biotechnology New Delhi, India
| | - Renu Tuteja
- Parasite Biology Group, International Centre for Genetic Engineering and Biotechnology New Delhi, India
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Rahman F, Tarique M, Tuteja R. Plasmodium falciparum Bloom homologue, a nucleocytoplasmic protein, translocates in 3' to 5' direction and is essential for parasite growth. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2016; 1864:594-608. [PMID: 26917473 DOI: 10.1016/j.bbapap.2016.02.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 02/16/2016] [Accepted: 02/18/2016] [Indexed: 12/25/2022]
Abstract
Malaria caused by Plasmodium, particularly Plasmodium falciparum, is the most serious and widespread parasitic disease of humans. RecQ helicase family members are essential in homologous recombination-based error-free DNA repair processes in all domains of life. RecQ helicases present in each organism differ and several homologues have been identified in various multicellular organisms. These proteins are involved in various pathways of DNA metabolism by providing duplex unwinding function. Five members of RecQ family are present in Homo sapiens but P. falciparum contains only two members of this family. Here we report the detailed biochemical and functional characterization of the Bloom (Blm) homologue (PfBlm) from P. falciparum 3D7 strain. Purified PfBlm exhibits ATPase and 3' to 5' direction specific DNA helicase activity. The calculated average reaction rate of ATPase was ~13 pmol of ATP hydrolyzed/min/pmol of enzyme. The immunofluorescence assay results show that PfBlm is expressed in all the stages of intraerythrocytic development of the P. falciparum 3D7 strain. In some stages of development in addition to nucleus PfBlm also localizes in the cytoplasm. The gene disruption studies of PfBlm by dsRNA showed that it is required for the ex-vivo intraerythrocytic development of the parasite P. falciparum 3D7 strain. The dsRNA mediated inhibition of parasite growth suggests that a variety of pathways are affected resulting in curtailing of the parasite growth. This study will be helpful in unravelling the basic mechanism of DNA transaction in the malaria parasite and additionally it may provide leads to understand the parasite specific characteristics of this protein.
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Affiliation(s)
- Farhana Rahman
- Malaria Group, International Centre for Genetic Engineering and Biotechnology, P. O. Box 10504, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Mohammed Tarique
- Malaria Group, International Centre for Genetic Engineering and Biotechnology, P. O. Box 10504, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Renu Tuteja
- Malaria Group, International Centre for Genetic Engineering and Biotechnology, P. O. Box 10504, Aruna Asaf Ali Marg, New Delhi 110067, India.
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Ahmad M, Tuteja R. Emerging importance of mismatch repair components including UvrD helicase and their cross-talk with the development of drug resistance in malaria parasite. Mutat Res 2014; 770:54-60. [PMID: 25771870 DOI: 10.1016/j.mrfmmm.2014.09.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Revised: 08/14/2014] [Accepted: 09/17/2014] [Indexed: 06/04/2023]
Abstract
Human malaria is an important parasitic infection responsible for a significant number of deaths worldwide, particularly in tropical and subtropical regions. The recent scenario has worsened mainly because of the emergence of drug-resistant malaria parasites having the potential to spread across the world. Drug-resistant parasites possess a defective mismatch repair (MMR); therefore, it is essential to explore its mechanism in detail to determine the underlying cause. Recently, artemisinin-resistant parasites have been reported to exhibit nonsynonymous single nucleotide polymorphisms in genes involved in MMR pathways such as MutL homolog (MLH) and UvrD. Plasmodium falciparum MLH is an endonuclease required to restore the defective MMR in drug-resistant W2 strain of P. falciparum. Although the role of helicases in eukaryotic MMR has been questioned, the identification and characterization of the UvrD helicase and their cross-talk with MLH in P. falciparum suggests the possible involvement of UvrD in MMR. A comparative genome-wide analysis revealed the presence of the UvrD helicase in Plasmodium species, while it is absent in human host. Therefore, PfUvrD may emerge as a suitable drug target to control malaria. This review study is focused on recent developments in MMR biochemistry, emerging importance of the UvrD helicase, possibility of its involvement in MMR and the emerging cross-talk between MMR components and drug resistance in malaria parasite.
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Affiliation(s)
- Moaz Ahmad
- Malaria Group, International Centre for Genetic Engineering and Biotechnology, P. O. Box 10504, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Renu Tuteja
- Malaria Group, International Centre for Genetic Engineering and Biotechnology, P. O. Box 10504, Aruna Asaf Ali Marg, New Delhi 110067, India.
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Abstract
Malaria is still a devastating disease caused by the mosquito-transmitted parasite Plasmodium, particularly Plasmodium falciparum. During the last few years the situation has worsened in many ways, mainly due to malarial parasites becoming increasingly resistant to several anti-malarial drugs. Thus there is an urgent need to find alternate ways to control malaria and therefore it is necessary to identify new drug targets and new classes of anti-malarial drugs. A malaria vaccine would be the ultimate weapon to fight this deadly disease but unfortunately despite encouraging advances a vaccine is not likely soon. DNA helicases from the PcrA/UvrD/Rep (PUR) subfamily are important for the survival of the various organisms, mainly pathogenic bacteria. Members from this subfamily can be targeted and inhibited by a variety of synthetic compounds. Using bioinformatics analysis we have shown that UvrD from this subfamily is the only member present in the P. falciparum genome, while PcrA and Rep are absent in the genome. UvrD from the parasite shows no homology to any protein or enzyme from human and thus can be considered as a strong potential drug target. In the present study we report an in silico analysis of this important enzyme from a variety of Plasmodium species. The results suggest that among all the species of Plasmodium, P. falciparum contains the largest UvrD and this enzyme is variable at the sequence and structural level.
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Affiliation(s)
- Renu Tuteja
- Malaria Group; International Centre for Genetic Engineering and Biotechnology; New Delhi, India
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Ahmad M, Ansari A, Tarique M, Satsangi AT, Tuteja R. Plasmodium falciparum UvrD helicase translocates in 3' to 5' direction, colocalizes with MLH and modulates its activity through physical interaction. PLoS One 2012; 7:e49385. [PMID: 23185322 PMCID: PMC3503981 DOI: 10.1371/journal.pone.0049385] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2012] [Accepted: 10/10/2012] [Indexed: 01/25/2023] Open
Abstract
Malaria is a global disease and a major health problem. The control of malaria is a daunting task due to the increasing drug resistance. Therefore, there is an urgent need to identify and characterize novel parasite specific drug targets. In the present study we report the biochemical characterization of parasite specific UvrD helicase from Plasmodium falciparum. The N-terminal fragment (PfUDN) containing UvrD helicase domain, which consists of helicase motifs Q, Ia-Id, II, III and most of motif IV, and the C-terminal fragment (PfUDC1) containing UvrD helicase C terminal domain, consisting of remaining part of motif IV and motifs IVa-IVc and 161 amino acids of intervening sequence between motif IV and V, possess ssDNA-dependent ATPase and DNA helicase activities in vitro. Using immunodepletion assays we show that the ATPase and helicase activities are attributable to PfUDN and PfUDC1 proteins. The helicase activity can utilize the hydrolysis of all the nucleotide and deoxynucleotide triphosphates and the direction of unwinding is 3' to 5'. The endogenous P. falciparum UvrD contains the characteristic DNA helicase activity. PfUDN interacts with PfMLH (P. falciparum MutL homologue) and modulates the endonuclease activity of PfMLH and PfMLH positively regulates the unwinding activity of PfUDN. We show that PfUvrD is expressed in the nucleus distinctly in the schizont stages of the intraerythrocytic development of the parasite and it colocalizes with PfMLH. These studies will make an important contribution in understanding the nucleic acid transaction in the malaria parasite.
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Affiliation(s)
- Moaz Ahmad
- Malaria Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India
| | - Abulaish Ansari
- Malaria Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India
| | - Mohammed Tarique
- Malaria Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India
| | - Akash Tripathi Satsangi
- Malaria Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India
| | - Renu Tuteja
- Malaria Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India
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Novel RuvB nuclear ATPase is specific to intraerythrocytic mitosis during schizogony of Plasmodium falciparum. Mol Biochem Parasitol 2012; 185:58-65. [DOI: 10.1016/j.molbiopara.2012.06.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Revised: 06/01/2012] [Accepted: 06/06/2012] [Indexed: 12/17/2022]
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Sequence-based association and selection scans identify drug resistance loci in the Plasmodium falciparum malaria parasite. Proc Natl Acad Sci U S A 2012; 109:13052-7. [PMID: 22826220 DOI: 10.1073/pnas.1210585109] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Through rapid genetic adaptation and natural selection, the Plasmodium falciparum parasite--the deadliest of those that cause malaria--is able to develop resistance to antimalarial drugs, thwarting present efforts to control it. Genome-wide association studies (GWAS) provide a critical hypothesis-generating tool for understanding how this occurs. However, in P. falciparum, the limited amount of linkage disequilibrium hinders the power of traditional array-based GWAS. Here, we demonstrate the feasibility and power improvements gained by using whole-genome sequencing for association studies. We analyzed data from 45 Senegalese parasites and identified genetic changes associated with the parasites' in vitro response to 12 different antimalarials. To further increase statistical power, we adapted a common test for natural selection, XP-EHH (cross-population extended haplotype homozygosity), and used it to identify genomic regions associated with resistance to drugs. Using this sequence-based approach and the combination of association and selection-based tests, we detected several loci associated with drug resistance. These loci included the previously known signals at pfcrt, dhfr, and pfmdr1, as well as many genes not previously implicated in drug-resistance roles, including genes in the ubiquitination pathway. Based on the success of the analysis presented in this study, and on the demonstrated shortcomings of array-based approaches, we argue for a complete transition to sequence-based GWAS for small, low linkage-disequilibrium genomes like that of P. falciparum.
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