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Iyer GR, Singh S, Kaur I, Agarwal S, Siddiqui MA, Bansal A, Kumar G, Saini E, Paul G, Mohmmed A, Chitnis CE, Malhotra P. Calcium-dependent phosphorylation of Plasmodium falciparum serine repeat antigen 5 triggers merozoite egress. J Biol Chem 2018; 293:9736-9746. [PMID: 29716996 DOI: 10.1074/jbc.ra117.001540] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 04/13/2018] [Indexed: 01/13/2023] Open
Abstract
The human malaria parasite Plasmodium falciparum proliferates in red blood cells following repeated cycles of invasion, multiplication, and egress. P. falciparum serine repeat antigen 5 (PfSERA5), a putative serine protease, plays an important role in merozoite egress. However, regulation of its activity leading to merozoite egress is poorly understood. In this study, we show that PfSERA5 undergoes phosphorylation prior to merozoite egress. Immunoprecipitation of parasite lysates using anti-PfSERA5 serum followed by MS analysis identified calcium-dependent protein kinase 1 (PfCDPK1) as an interacting kinase. Association of PfSERA5 with PfCDPK1 was corroborated by co-sedimentation, co-immunoprecipitation, and co-immunolocalization analyses. Interestingly, PfCDPK1 phosphorylated PfSERA5 in vitro in the presence of Ca2+ and enhanced its proteolytic activity. A PfCDPK1 inhibitor, purfalcamine, blocked the phosphorylation and activation of PfSERA5 both in vitroas well as in schizonts, which, in turn, blocked merozoite egress. Together, these results suggest that phosphorylation of PfSERA5 by PfCDPK1 following a rise in cytosolic Ca2+ levels activates its proteolytic activity to trigger merozoite egress.
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Affiliation(s)
- Gayatri R Iyer
- From the Malaria Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110 067, India and
| | - Shailja Singh
- From the Malaria Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110 067, India and.,the Department of Parasites and Insect Vectors, Institut Pasteur, 25-28 rue du Doctor Roux, 75015 Paris, France
| | - Inderjeet Kaur
- From the Malaria Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110 067, India and
| | - Shalini Agarwal
- From the Malaria Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110 067, India and
| | - Mansoor A Siddiqui
- From the Malaria Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110 067, India and
| | - Abhisheka Bansal
- From the Malaria Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110 067, India and
| | - Gautam Kumar
- From the Malaria Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110 067, India and
| | - Ekta Saini
- From the Malaria Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110 067, India and
| | - Gourab Paul
- From the Malaria Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110 067, India and
| | - Asif Mohmmed
- From the Malaria Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110 067, India and
| | - Chetan E Chitnis
- From the Malaria Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110 067, India and .,the Department of Parasites and Insect Vectors, Institut Pasteur, 25-28 rue du Doctor Roux, 75015 Paris, France
| | - Pawan Malhotra
- From the Malaria Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110 067, India and
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2
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Jackson AP. Gene family phylogeny and the evolution of parasite cell surfaces. Mol Biochem Parasitol 2016; 209:64-75. [DOI: 10.1016/j.molbiopara.2016.03.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 03/18/2016] [Accepted: 03/19/2016] [Indexed: 11/30/2022]
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3
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Rahul CN, Shiva Krishna K, Meera M, Phadke S, Rajesh V. Plasmodium vivax: N-terminal diversity in the blood stage SERA genes from Indian isolates. Blood Cells Mol Dis 2015; 55:30-5. [PMID: 25976464 DOI: 10.1016/j.bcmd.2015.03.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 03/29/2015] [Indexed: 11/17/2022]
Abstract
Worldwide malaria risk due to Plasmodium vivax makes development of vaccine against P. vivax, a high priority. Serine Repeat Antigen of P. vivax (PvSERA) is a multigene family of blood stage proteins with 12 homologues. Sequence diversity studies are important for understanding them as potential vaccine candidates. No information on N-terminal diversity of these genes is available in literature. In this paper, we evaluate the genetic polymorphism of N-terminal regions of the highly expressed member PvSERA4 and PvSERA5 genes from Indian field isolates. Our results show that PvSERA4 has deletions and insertions in Glutamine rich tetrameric repeat units contributing to its diversity. PvSERA5 also exhibits high genetic diversity with non-synonymous substitutions leading to identification of novel haplotypes from India. Our first report helps in elucidating the allelic variants of PvSERA genes in this region and contributes to evaluating their efficacy as vaccine candidates.
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Affiliation(s)
- C N Rahul
- Department of Biological Sciences, Birla Institute of Technology and Science, Pilani, Hyderabad Campus, Andhra Pradesh, India
| | - K Shiva Krishna
- Department of Biological Sciences, Birla Institute of Technology and Science, Pilani, Hyderabad Campus, Andhra Pradesh, India
| | - M Meera
- Sir Ronald Ross Institute of Tropical and Communicable Diseases, Hyderabad, Andhra Pradesh, India
| | | | - Vidya Rajesh
- Department of Biological Sciences, Birla Institute of Technology and Science, Pilani, Hyderabad Campus, Andhra Pradesh, India.
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4
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Rahul C, Shiva Krishna K, Meera Bai N, Kumar V, Phadke S, Rajesh V. Plasmodium vivax: C-terminal diversity in the blood stage SERA genes from Indian field isolates. Exp Parasitol 2013; 134:82-91. [DOI: 10.1016/j.exppara.2013.02.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Revised: 12/21/2012] [Accepted: 02/05/2013] [Indexed: 10/27/2022]
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5
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Rahul CN, Shiva Krishna K, Pawar AP, Bai M, Kumar V, Phadke S, Rajesh V. Genetic and structural characterization of PvSERA4: potential implication as therapeutic target for Plasmodium vivax malaria. J Biomol Struct Dyn 2013; 32:580-90. [PMID: 23582016 DOI: 10.1080/07391102.2013.782824] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Plasmodium vivax malaria is geographically the most widely distributed and prevalent form of human malaria. The development of drug resistance by the parasite to existing drugs necessitates higher focus to explore and identify new drug targets. Plasmodial proteases have key roles in parasite biology and are involved in nutritional uptake, egress from infected reticulocytes, and invasion of the new target erythrocytes. Serine repeat antigens (SERA) of Plasmodium are parasite proteases that remain attractive drug targets and are important vaccine candidates due to their high expression profiles in the blood stages. SERA proteins have a unique putative papain-like cysteine protease motif that has either serine or cysteine in its active site. In P. vivax, PvSERA4 is the highest transcribed member of this multigene family. In this study, we have investigated the genetic polymorphism of PvSERA4 central protease domain and deduced its 3D model by homology modeling and also performed MD simulations to acquire refined protein structure. Sequence analysis of protease domain of PvSERA4 from Indian field isolates reveals that the central domain is highly conserved. The high sequence conservation of the PvSERA4 enzyme domain coupled with its high expression raises the possibility of it having a critical role in parasite biology and hence, being a reliable target for new selective inhibitor-based antimalarial chemotherapeutics. The 3D model showed the presence of an unusual antiparallel Beta hairpin motif between catalytic residues similar to hemoglobin binding motif of Plasmodial hemoglobinases. Our PvSERA4 model will aid in designing structure-based inhibitors against this enzyme.
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Affiliation(s)
- C N Rahul
- a Department of Biological Sciences , Birla Institute of Technology and Science, Pilani , Hyderabad Campus , Andhra Pradesh , India
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6
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Rosenthal PJ. Falcipains and other cysteine proteases of malaria parasites. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2011; 712:30-48. [PMID: 21660657 DOI: 10.1007/978-1-4419-8414-2_3] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A number of cysteine proteases of malaria parasites have been described and many more are suggested by analysis of the Plasmodium falciparum genome sequence. The best characterized of these proteases are the falcipains, a family of four papain-family enzymes. Falcipain-2 and falcipain-3 act in concert with other proteases to hydrolyze host erythrocyte hemoglobin in the parasite food vacuole. Disruption of the falcipain-2 gene led to a transient block in hemoglobin hydrolysis and parasites with increased sensitivity to protease inhibitors. Disruption of the falcipain-3 gene was not possible, strongly suggesting that this protease is essential for erythrocytic parasites. Disruption of the falcipain-1 gene did not alter development in erythrocytes, but led to decreased production of oocysts in mosquitoes. other papain-family proteases predicted by the genome sequence include dipeptidyl peptidases, a calpain homolog and serine-repeat antigens (SERAs). Dipeptidyl aminopeptidase 1 appears to be essential and localized to the food vacuole, suggesting a role in hemoglobin hydrolysis. Dipeptidyl aminopeptidase 3 appears to play a role in the rupture of erythrocytes by mature parasites. the P. falciparum calpain homolog gene could not be disrupted, suggesting that the protein is essential and a role in the parasite cell cycle has been suggested. Nine P. falciparum SERAs have cysteine protease motifs, but in some the active site cys is replaced by a Ser. Gene disruption studies suggested that SERA-5 and SERA-6 are essential. activation of SERA-5 by a serine protease seems to be required for merozoite egress from the erythrocyte. New drugs for malaria are greatly needed and cysteine proteases represent potential drug targets. cysteine protease inhibitors have demonstrated potent antimalarial effects and the optimization and testing of falcipain inhibitor antimalarials is underway.
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Affiliation(s)
- Philip J Rosenthal
- Department of Medicine, San Francisco General Hospital, University of California, San Francisco, California, USA.
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7
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Inhibition of malaria parasite development by a cyclic peptide that targets the vital parasite protein SERA5. Infect Immun 2008; 76:4332-44. [PMID: 18591232 DOI: 10.1128/iai.00278-08] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The serine repeat antigen (SERA) proteins of the malaria parasites Plasmodium spp. contain a putative enzyme domain similar to that of papain family cysteine proteases. In Plasmodium falciparum parasites, more than half of the SERA family proteins, including the most abundantly expressed form, SERA5, have a cysteine-to-serine substitution within the putative catalytic triad of the active site. Although SERA5 is required for blood-stage parasite survival, the occurrence of a noncanonical catalytic triad casts doubt on the importance of the enzyme domain in this function. We used phage display to identify a small (14-residue) disulfide-bonded cyclic peptide (SBP1) that targets the enzyme domain of SERA5. Biochemical characterization of the interaction shows that it is dependent on the conformation of both the peptide and protein. Addition of this peptide to parasite cultures compromised development of late-stage parasites compared to that of control parasites or those incubated with equivalent amounts of the carboxymethylated peptide. This effect was similar in two different strains of P. falciparum as well as in a transgenic strain where the gene encoding the related serine-type parasitophorous vacuole protein SERA4 was deleted. In compromised parasites, the SBP1 peptide crosses both the erythrocyte and parasitophorous vacuole membranes and accumulates within the parasitophorous vacuole. In addition, both SBP1 and SERA5 were identified in the parasite cytosol, indicating that the plasma membrane of the parasite was compromised as a result of SBP1 treatment. These data implicate an important role for SERA5 in the regulation of the intraerythrocytic development of late-stage parasites and as a target for drug development.
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8
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Abstract
Malaria is a scourge of large swathes of the globe, stressing the need for a continuing effort to better understand the biology of its aetiological agent. Like all pathogens of the phylum Apicomplexa, the malaria parasite spends part of its life inside a host cell or cyst. It eventually needs to escape (egress) from this protective environment to progress through its life cycle. Egress of Plasmodium blood-stage merozoites, liver-stage merozoites and mosquito midgut sporozoites relies on protease activity, so the enzymes involved have potential as antimalarial drug targets. This review examines the role of parasite proteases in egress, in the light of current knowledge of the mechanics of the process. Proteases implicated in egress include the cytoskeleton-degrading malarial proteases falcipain-2 and plasmepsin II, plus a family of putative papain-like proteases called SERA. Recent revelations have shown that activation of the SERA proteases may be triggered by regulated secretion of a subtilisin-like serine protease called SUB1. These findings are discussed in the context of the potential for development of new chemotherapeutics targeting this stage in the parasite's life cycle.
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Affiliation(s)
- Michael J Blackman
- Division of Parasitology, National Institute for Medical Research, Mill Hill, London NW7 1AA, UK.
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9
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Arisue N, Hirai M, Arai M, Matsuoka H, Horii T. Phylogeny and evolution of the SERA multigene family in the genus Plasmodium. J Mol Evol 2007; 65:82-91. [PMID: 17609844 DOI: 10.1007/s00239-006-0253-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2006] [Accepted: 04/04/2007] [Indexed: 11/26/2022]
Abstract
The serine repeat antigen gene family of Plasmodium falciparum (Pf-SERA) consists of nine gene members. By sequence similarity search, 45 genes were identified to be homologous to the Pf-SERA genes in the ongoing seven Plasmodium genome sequencing project databases for the species: P. reichenowi, P. vivax, P. knowlesi, P. yoelii, P. berghei, P. chabaudi, and P. gallinaceum. In combination with additional PCR-based sequencing, we found that almost all SERA genes in each species were aligned in a tandem cluster and sandwiched between two conserved hypothetical protein genes, except for P. reichenowi, which could not be confirmed. The minimum and maximum numbers of clustered genes were 2 and 12 for P. gallinaceum and P. vivax, respectively. The best tree of the maximum likelihood analysis demonstrated that all Plasmodium SERA homologues, except for SERA1 of P. gallinaceum (Pg-SERA1), can be classified into four groups, represented by Pf-SERA5, Pf-SERA6, Pf-SERA7, and Pf-SERA8. Genes in the Pf-SERA8 group, although highly divergent and distantly related to the sequences of other groups, were not pseudogenes. P. berghei SERA5, the counterpart of Pf-SERA8, was expressed in the mosquito stage. P. gallinaceum lacks the orthologues to Pf-SERA5, Pf-SERA6, and Pf-SERA7, suggesting that P. gallinaceum diverged from a common ancestor of all eight Plasmodium species examined before gene duplication(s) occurred to generate these paralogous groups. Here, we reveal an evolutionary trail of SERA gene cluster in the genus Plasmodium and discuss a phylogeny of Plasmodium species from the viewpoint of the evolution of a multigene family.
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Affiliation(s)
- Nobuko Arisue
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka Suita, Osaka 565-0871, Japan
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10
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Palacpac NMQ, Leung BWY, Arisue N, Tanabe K, Sattabongkot J, Tsuboi T, Torii M, Udomsangpetch R, Horii T. Plasmodium vivax serine repeat antigen (SERA) multigene family exhibits similar expression patterns in independent infections. Mol Biochem Parasitol 2006; 150:353-8. [PMID: 16934884 DOI: 10.1016/j.molbiopara.2006.07.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2006] [Revised: 07/13/2006] [Accepted: 07/14/2006] [Indexed: 11/27/2022]
Affiliation(s)
- Nirianne Marie Q Palacpac
- Department of Molecular Protozoology, Research Institute for Microbial Diseases (BIKEN), Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan
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11
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Hurd H, Grant KM, Arambage SC. Apoptosis-like death as a feature of malaria infection in mosquitoes. Parasitology 2006; 132 Suppl:S33-47. [PMID: 17018164 DOI: 10.1017/s0031182006000849] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Malaria parasites of the genusPlasmodiummake a hazardous journey through their mosquito vectors. The majority die in the process, many as a result of the action of mosquito defence mechanisms. The mosquito too is not unscathed by the encounter with these parasites. Tissue damage occurs as a result of mid-gut invasion and reproductive fitness is lost when many developing ovarian follicles are resorbed. Here we discuss some of the mechanisms that are involved in killing the parasite and in the self-defence mechanisms employed by the mosquito to repair the mid-gut epithelium and to manipulate resources altering the trade-off position that balances reproduction and survival. In all cases, cells die by apoptotic-like mechanisms. In the midgut cells, apoptosis-induction pathways are being elucidated, the molecules involved in apoptosis are being recognised andDrosophilahomologues sought. The death of ookinetes in the mosquito mid-gut lumen is associated with caspase-like activity and, although homologues of mammalian caspases are not present in the malaria genome, other cysteine proteases that are potential candidates have been discussed. In the ovary, apoptosis of patches of follicular epithelial cells is followed by resorption of the developing follicle and a subsequent loss of egg production in that follicle.
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Affiliation(s)
- H Hurd
- Centre for Applied Entomology and Parasitology, Institute for Science and Technology in Medicine, University of Keele, Staffordshire, ST5 5BG, UK. h.hurd.keele.ac.uk
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12
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Rosenthal PJ. Cysteine proteases of malaria parasites. Int J Parasitol 2004; 34:1489-99. [PMID: 15582526 DOI: 10.1016/j.ijpara.2004.10.003] [Citation(s) in RCA: 244] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2004] [Revised: 10/07/2004] [Accepted: 10/07/2004] [Indexed: 11/23/2022]
Abstract
A number of cysteine proteases of malaria parasites have been described, and many more putative cysteine proteases are suggested by analysis of the Plasmodium falciparum genome sequence. Studies with protease inhibitors have suggested roles for cysteine proteases in hemoglobin hydrolysis, erythrocyte rupture, and erythrocyte invasion by erythrocytic malaria parasites. The best characterised Plasmodium cysteine proteases are the falcipains, a family of papain-family (clan CA) enzymes. Falcipain-2 and falcipain-3 are hemoglobinases that appear to hydrolyse host erythrocyte hemoglobin in the parasite food vacuole. This function was recently confirmed for falcipain-2, with the demonstration that disruption of the falcipain-2 gene led to a transient block in hemoglobin hydrolysis. A role for falcipain-1 in erythrocyte invasion was recently suggested, but disruption of the falcipain-1 gene did not alter parasite development. Other papain-family proteases predicted by the genome sequence include dipeptidyl peptidases, a calpain homolog, and serine-repeat antigens. The serine-repeat antigens have cysteine protease motifs, but in some the active site Cys is replaced by a Ser. One of these proteins, SERA-5, was recently shown to have serine protease activity. As SERA-5 and some other serine-repeat antigens localise to the parasitophorous vacuole in mature parasites, they may play a role in erythrocyte rupture. The P. falciparum genome sequence also predicts more distantly related (clan CD and CE) cysteine proteases, but biochemical characterisation of these proteins has not been done. New drugs for malaria are greatly needed, and cysteine proteases may provide useful new drug targets. Cysteine protease inhibitors have demonstrated potent antimalarial effects, and the optimisation and testing of falcipain inhibitor antimalarials is underway.
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Affiliation(s)
- Philip J Rosenthal
- Department of Medicine, San Francisco General Hospital, University of California, San Francisco, Box 0811, San Francisco, CA 94143, USA.
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13
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Bourgon R, Delorenzi M, Sargeant T, Hodder AN, Crabb BS, Speed TP. The serine repeat antigen (SERA) gene family phylogeny in Plasmodium: the impact of GC content and reconciliation of gene and species trees. Mol Biol Evol 2004; 21:2161-71. [PMID: 15306658 DOI: 10.1093/molbev/msh228] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Plasmodium falciparum is the parasite responsible for the most acute form of malaria in humans. Recently, the serine repeat antigen (SERA) in P. falciparum has attracted attention as a potential vaccine and drug target, and it has been shown to be a member of a large gene family. To clarify the relationships among the numerous P. falciparum SERAs and to identify orthologs to SERA5 and SERA6 in Plasmodium species affecting rodents, gene trees were inferred from nucleotide and amino acid sequence data for 33 putative SERA homologs in seven different species. (A distance method for nucleotide sequences that is specifically designed to accommodate differing GC content yielded results that were largely compatible with the amino acid tree. Standard-distance and maximum-likelihood methods for nucleotide sequences, on the other hand, yielded gene trees that differed in important respects.) To infer the pattern of duplication, speciation, and gene loss events in the SERA gene family history, the resulting gene trees were then "reconciled" with two competing Plasmodium species tree topologies that have been identified by previous phylogenetic studies. Parsimony of reconciliation was used as a criterion for selecting a gene tree/species tree pair and provided (1) support for one of the two species trees and for the core topology of the amino acid-derived gene tree, (2) a basis for critiquing fine detail in a poorly resolved region of the gene tree, (3) a set of predicted "missing genes" in some species, (4) clarification of the relationship among the P. falciparum SERA, and (5) some information about SERA5 and SERA6 orthologs in the rodent malaria parasites. Parsimony of reconciliation and a second criterion--implied mutational pattern at two key active sites in the SERA proteins-were also seen to be useful supplements to standard "bootstrap" analysis for inferred topologies.
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Affiliation(s)
- Richard Bourgon
- Department of Statistics, University of California, Berkeley, USA
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14
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Hodder AN, Drew DR, Epa VC, Delorenzi M, Bourgon R, Miller SK, Moritz RL, Frecklington DF, Simpson RJ, Speed TP, Pike RN, Crabb BS. Enzymic, phylogenetic, and structural characterization of the unusual papain-like protease domain of Plasmodium falciparum SERA5. J Biol Chem 2003; 278:48169-77. [PMID: 13679369 DOI: 10.1074/jbc.m306755200] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Serine repeat antigen 5 (SERA5) is an abundant antigen of the human malaria parasite Plasmodium falciparum and is the most strongly expressed member of the nine-gene SERA family. It appears to be essential for the maintenance of the erythrocytic cycle, unlike a number of other members of this family, and has been implicated in parasite egress and/or erythrocyte invasion. All SERA proteins possess a central domain that has homology to papain except in the case of SERA5 (and some other SERAs), where the active site cysteine has been replaced with a serine. To investigate if this domain retains catalytic activity, we expressed, purified, and refolded a recombinant form of the SERA5 enzyme domain. This protein possessed chymotrypsin-like proteolytic activity as it processed substrates downstream of aromatic residues, and its activity was reversed by the serine protease inhibitor 3,4-diisocoumarin. Although all Plasmodium SERA enzyme domain sequences share considerable homology, phylogenetic studies revealed two distinct clusters across the genus, separated according to whether they possess an active site serine or cysteine. All Plasmodia appear to have at least one member of each group. Consistent with separate biological roles for members of these two clusters, molecular modeling studies revealed that SERA5 and SERA6 enzyme domains have dramatically different surface properties, although both have a characteristic papain-like fold, catalytic cleft, and an appropriately positioned catalytic triad. This study provides impetus for the examination of SERA5 as a target for antimalarial drug design.
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Affiliation(s)
- Anthony N Hodder
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, 1G Royal Parade, Parkville, Victoria 3050, Australia.
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15
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Miller SK, Good RT, Drew DR, Delorenzi M, Sanders PR, Hodder AN, Speed TP, Cowman AF, de Koning-Ward TF, Crabb BS. A subset of Plasmodium falciparum SERA genes are expressed and appear to play an important role in the erythrocytic cycle. J Biol Chem 2002; 277:47524-32. [PMID: 12228245 DOI: 10.1074/jbc.m206974200] [Citation(s) in RCA: 127] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Plasmodium falciparum serine repeat antigen (SERA) has shown considerable promise as a blood stage vaccine for the control of malaria. A related protein, SERPH, has also been described in P. falciparum. Whereas their biological role remains unknown, both proteins possess papain-like protease domains that may provide attractive targets for therapeutic intervention. Genomic sequencing has recently shown that SERA and SERPH are the fifth and sixth genes, respectively, in a cluster of eight SERA homologues present on chromosome 2. In this paper, the expression and functional relevance of these eight genes and of a ninth SERA homologue found on chromosome 9 were examined in blood stage parasites. Using reverse transcriptase-PCR and microarray approaches, we demonstrate that whereas mRNA to all nine SERA genes is synthesized late in the erythrocytic cycle, it is those genes in the central region of the chromosome 2 cluster that are substantially up-regulated at this time. Using antibodies specific to each SERA, it was apparent that SERA4 to -6, and possibly also SERA9, are synthesized in blood stage parasites. The reactivity of antibodies from malaria-immune individuals with the SERA recombinant proteins suggested that SERA2 and SERA3 are also expressed at least in some parasite populations. To examine whether SERA genes are essential to blood stage growth, each of the eight chromosome 2 SERA genes was targeted for disruption. Whereas genes at the periphery of the cluster were mostly dispensable (SERA2 and -3 and SERA7 and -8), those in the central region (SERA4 to -6) could not be disrupted. The inability to disrupt SERA4, -5, and -6 is consistent with their apparent dominant expression and implies an important role for these genes in maintenance of the erythrocytic cycle.
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MESH Headings
- Animals
- Antigens, Protozoan/biosynthesis
- Antigens, Protozoan/genetics
- Blotting, Southern
- Blotting, Western
- Chromosomes
- DNA/metabolism
- Electrophoresis, Polyacrylamide Gel
- Erythrocytes/metabolism
- Erythrocytes/parasitology
- Female
- Fluorescent Antibody Technique, Indirect
- Glutathione Transferase/metabolism
- Mice
- Mice, Inbred BALB C
- Microscopy, Fluorescence
- Models, Genetic
- Multigene Family
- Oligonucleotide Array Sequence Analysis
- Plasmodium falciparum/genetics
- Plasmodium falciparum/metabolism
- Protein Structure, Tertiary
- Rabbits
- Recombinant Proteins/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Time Factors
- Transfection
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Affiliation(s)
- Susanne K Miller
- Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria 3050, Australia
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Mercereau-Puijalon O, Barale JC, Bischoff E. Three multigene families in Plasmodium parasites: facts and questions. Int J Parasitol 2002; 32:1323-44. [PMID: 12350369 DOI: 10.1016/s0020-7519(02)00111-x] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Multigene families optimise fitness by providing a set of related genes with possibly different temporal and/or topological expression patterns. We analyse here the structural organisation and sequence diversity of the rDNA, sera and var C Plasmodium falciparum families, and discuss their consequences for parasite biology. The low rDNA copy number, which reduces reshuffling, is probably the corollary of the need for functionally distinct rRNAs in the insect and in the vertebrate host. The unusual intra-genome and population rDNA sequence diversity results in cells equipped with mosaic ribosome sets. The functional constraints are such that ribosome compatibility could influence parasite fitness and contribute to population structuring. Unlike the dispersed rDNA units, the sera family is arranged as a tandem gene cluster, with seven contiguous similar genes, and one more distantly related paralog. We address the question of the inclusion criteria in family definition. We discuss the results concerning the SERA proteins expression and function in the context of the long overlooked multigene family. The var C module is shared by var genes, 'orphan' var C and var C pseudogenes. Analysis of 125 var C deduced protein sequences highlights a well-conserved framework, including putative phosphorylation sites, consistent with the proposed function of mediating interaction with cytoskeletal proteins. The 5' and 3' flanking sequences of the var C pseudogenes are heterogeneous. In contrast, the flanking sequences of the uninterrupted var C modules show remarkable conservation. This is interesting in view of the silencing activity of the var intronic sequence on var expression. The 5' flanking sequence dichotomy reported for internal and sub-telomeric var genes extends to the 3' flanking sequences. This has profound implications for transcription regulation and generation of diversity. The var C family suggests a role for pseudogenes as a diversity reservoir and in genome dynamics by promoting ectopic recombination.
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Affiliation(s)
- Odile Mercereau-Puijalon
- Unité d'Immunologie Moléculaire des Parasites, Unité de Recherche Associée 1960 du Centre National de la Recherche Scientifique, Institut Pasteur, 25 rue du Dr ROUX, 75015, Paris, France.
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Carlton JM, Galinski MR, Barnwell JW, Dame JB. Karyotype and synteny among the chromosomes of all four species of human malaria parasite. Mol Biochem Parasitol 1999; 101:23-32. [PMID: 10413040 DOI: 10.1016/s0166-6851(99)00045-6] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The karyotype and chromosomes of the human malaria parasite Plasmodium falciparum have been well characterized in recent years. Here we present karyotype maps of the three other human malaria species, P. vivax, P. malariae and P. ovale. Chromosomes of these species were found to be of significantly higher molecular weight than those of P. falciparum. Some 14 P. vivax chromosomes were distinguishable, and 12-14 P. malariae and P. ovale chromosomes. The chromosome location of 15 genes, known to be present within five synteny groups between P. falciparum and the rodent malarias, were analyzed, and four of these synteny groups were found to be conserved between all of the human malaria species. In addition, a more detailed genome map of P. vivax was made using ten housekeeping and antigen genes. These data represent the first karyotype maps of all species of malaria which infect man.
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Affiliation(s)
- J M Carlton
- Department of Pathobiology, College of Veterinary Medicine, University of Florida, Gainesville 32610, USA.
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Carlton JM. Gene synteny across Plasmodium spp: could 'operon-like' structures exist? PARASITOLOGY TODAY (PERSONAL ED.) 1999; 15:178-9. [PMID: 10322349 DOI: 10.1016/s0169-4758(99)01438-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- J M Carlton
- University of Florida, College of Veterinary Medicine, PO Box 110880, Gainesville, FL 32610, USA.
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Abstract
Codon usage in Plasmodium vivax nuclear genes was analysed and compared with that in Plasmodium falciparum nuclear genes. Preferred codons were determined for P. vivax. Unlike P. falciparum, P. vivax genes are about 15% less A+T rich in the coding regions, with no obvious A+T bias at the third position of the codons. The amino-acid composition of P. vivax gene products is also different from that of P. falciparum. These results provide valuable information to facilitate gene cloning as well as expression and transfection studies for P. vivax.
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Affiliation(s)
- N Chen
- Parasitology Department, Australian Army Malaria Institute, Brisbane, Queensland.
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Gor DO, Li AC, Rosenthal PJ. Protective immune responses against protease-like antigens of the murine malaria parasite Plasmodium vinckei. Vaccine 1998; 16:1193-202. [PMID: 9682379 DOI: 10.1016/s0264-410x(98)80119-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The Plasmodium falciparum proteins serine repeat antigen (SERA) and serine repeat protein homologue (SERPH) have similarity in sequence with cysteine proteases in a well-conserved protease domain. We identified three SERA homologues from the murine malaria parasite Plasmodium vinckei and evaluated immune responses to the protease domains of these proteins. Mice that developed protective immunity to P. vinckei after serial infection and cure demonstrated humoral and cell-mediated responses against the SERA homologue protease domains. Mice immunized with Salmonella typhimurium expressing the protease domain of one of these antigens demonstrated cellular responses against the antigen and increased survival against lethal challenge with P. vinckei. Our results suggest that the protease domains of SERA and SERPH are worthy of additional study as potential components of a malaria vaccine.
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Affiliation(s)
- D O Gor
- Department of Medicine, San Francisco General Hospital, CA, USA
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Marshall VM, Tieqiao W, Coppel RL. Close linkage of three merozoite surface protein genes on chromosome 2 of Plasmodium falciparum. Mol Biochem Parasitol 1998; 94:13-25. [PMID: 9719507 DOI: 10.1016/s0166-6851(98)00045-0] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We have analysed a 10.5 kb region of chromosome 2 in Plasmodium falciparum that encompasses the coding region of four genes. Three genes are arranged in a head-to-tail orientation and encode the merozoite surface proteins MSP2 and MSP4 as well as a previously unreported sequence that encodes a polypeptide with the characteristics of a merozoite surface protein, now designated MSP5. The fourth gene, asl, is arranged in a tail-to-tail orientation with msp2 and has homology with prokaryotic and eukaryotic genes encoding adenylosuccinate lyase (ASL), an enzyme involved in purine biosynthesis and salvage. The genes, arranged in the order msp4, msp5, msp2 and asl, are separated by intergenic distances of 1021, 1017 and 722 bp, respectively. msp4 and msp5 are clearly related genes, each being composed of 2 exons and encoding proteins of identical length. Both msp4 and msp5 encode proteins that contain hydrophobic signal sequences, apparent glycosylphosphatidylinositol (GPI) attachment signals and a single epidermal growth factor-like (EGF-like) domain at their carboxyl termini. Nevertheless, the remainder of their protein coding regions are quite dissimilar. It appears that one of these genes arose as a result of a relatively ancient gene duplication event and both genes have subsequently diverged considerably. This study shows that msp5 is transcribed in asexual stages and its encoded product is a 40 kDa protein that appears to be located on the merozoite surface as determined by immunofluorescence assays.
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Affiliation(s)
- V M Marshall
- The Walter and Eliza Hall Institute of Medical Research, Royal Melbourne Hospital, Victoria, Australia.
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