Identifying and characterizing a member of the RhopH1/Clag family in Plasmodium vivax

Moreno-Pérez, Darwin A.; Mongui, Alvaro; Soler, Laura N.; Sanchez-Ladino, Milena; Patarroyo, Manuel A.

doi:10.1016/j.gene.2011.03.007

Cited by 6 publications

(4 citation statements)

References 49 publications

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“…Pv RON4 amino acid alignment with Pf RON4 and Pk RON4 showed that ID and SI values were greater with Pk RON4 (Figure 2) thereby agreeing with the close relationship between these two parasite species. This coincided with previous studies showing greater similarity between P. vivax and P. knowlesi proteins than with other Plasmodium species [10,11]. Conservation was also found regarding the structure of genes upstream and downstream ron4 in P. falciparum , P. vivax and P. knowlesi , having 61.1%-97% and 77.6%-99.7% amino acid ID and SI values for Pk-Pv respectively, and 33.6%-88% and 54%-100% for Pf-Pv , respectively (Figure 2).…”

Section: Resultssupporting

confidence: 92%

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Annotation and characterization of the Plasmodium vivax rhoptry neck protein 4 (Pv RON4)

Arévalo-Pinzón

Curtidor

Abril

et al. 2013

Malar J

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BackgroundThe tight junction (TJ) is one of the most important structures established during merozoite invasion of host cells and a large amount of proteins stored in Toxoplasma and Plasmodium parasites’ apical organelles are involved in forming the TJ. Plasmodium falciparum and Toxoplasma gondii apical membrane antigen 1 (AMA-1) and rhoptry neck proteins (RONs) are the two main TJ components. It has been shown that RON4 plays an essential role during merozoite and sporozoite invasion to target cells. This study has focused on characterizing a novel Plasmodium vivax rhoptry protein, RON4, which is homologous to PfRON4 and PkRON4.MethodsThe ron4 gene was re-annotated in the P. vivax genome using various bioinformatics tools and taking PfRON4 and PkRON4 amino acid sequences as templates. Gene synteny, as well as identity and similarity values between open reading frames (ORFs) belonging to the three species were assessed. The gene transcription of pvron4, and the expression and localization of the encoded protein were also determined in the VCG-1 strain by molecular and immunological studies. Nucleotide and amino acid sequences obtained for pvron4 in VCG-1 were compared to those from strains coming from different geographical areas.ResultsPvRON4 is a 733 amino acid long protein, which is encoded by three exons, having similar transcription and translation patterns to those reported for its homologue, PfRON4. Sequencing PvRON4 from the VCG-1 strain and comparing it to P. vivax strains from different geographical locations has shown two conserved regions separated by a low complexity variable region, possibly acting as a “smokescreen”. PvRON4 contains a predicted signal sequence, a coiled-coil α-helical motif, two tandem repeats and six conserved cysteines towards the carboxy-terminus and is a soluble protein lacking predicted transmembranal domains or a GPI anchor. Indirect immunofluorescence assays have shown that PvRON4 is expressed at the apical end of schizonts and co-localizes at the rhoptry neck with PvRON2.ConclusionsGenomic, transcriptional and expression data reported for PvRON4, as well as its primary structure characteristics suggest that this protein participates in reticulocyte invasion, as has been shown for its homologue PfRON4.

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Section: Resultssupporting

confidence: 92%

“…Among the various strategies being used to overcome this problem, comparative analysis with other species, such as P. falciparum and adapting P. vivax strains to Aotus monkeys [7], have allowed the identification during the last few years of several antigens in P. vivax which could be participating in invasion [8-11]. …”

Section: Introductionmentioning

confidence: 99%

Annotation and characterization of the Plasmodium vivax rhoptry neck protein 4 (Pv RON4)

Arévalo-Pinzón

Curtidor

Abril

et al. 2013

Malar J

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“…It is worth noting that the high degree of S observed between P. vivax - P. knowlesi was in agreement with the evolutionary proximity found in a previous phylogenetic analysis of conserved regions from the circumsporozoite protein (CSP) encoding gene [50] and in a comparative genomics study of P. vivax [23] which showed that these organisms share similar chromosomal regions. Interestingly, the Id value found between the alignment of ORFs encoded by pfasp (PFD0295c) and pvron1 (PVX_000945) genes was similar to the Id values found in antigens considered good candidates for designing an effective vaccine against P. vivax malaria [22,28,29], suggesting that Pv RON1 should be an interesting candidate for immunological trials.…”

Section: Resultssupporting

confidence: 61%

“…Taking this into account and considering the degree of conservation observed between the genetic content of different Plasmodium species [23,24], some bioinformatics tools have been used for homology searches of the complete P. vivax genome for antigens already described in P. falciparum . To date, a considerable number of surface [25-28] and rhoptry proteins [22,29-35] have been experimentally identified and characterized in P. vivax using both its genome [21] and intraerythrocyte lifecycle transcriptome [36] as well as an Aotus -adapted strain [37]. These proteins belong to a list of antigens, which are being tested as vaccine candidates in the Aotus monkey model.…”

Section: Introductionmentioning

confidence: 99%

Identification, characterization and antigenicity of the Plasmodium vivax rhoptry neck protein 1 (Pv RON1)

Moreno-Pérez

Patarroyo

2011

Malar J

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BackgroundPlasmodium vivax malaria remains a major health problem in tropical and sub-tropical regions worldwide. Several rhoptry proteins which are important for interaction with and/or invasion of red blood cells, such as PfRONs, Pf92, Pf38, Pf12 and Pf34, have been described during the last few years and are being considered as potential anti-malarial vaccine candidates. This study describes the identification and characterization of the P. vivax rhoptry neck protein 1 (PvRON1) and examine its antigenicity in natural P. vivax infections.MethodsThe PvRON1 encoding gene, which is homologous to that encoding the P. falciparum apical sushi protein (ASP) according to the plasmoDB database, was selected as our study target. The pvron1 gene transcription was evaluated by RT-PCR using RNA obtained from the P. vivax VCG-1 strain. Two peptides derived from the deduced P. vivax Sal-I PvRON1 sequence were synthesized and inoculated in rabbits for obtaining anti-PvRON1 antibodies which were used to confirm the protein expression in VCG-1 strain schizonts along with its association with detergent-resistant microdomains (DRMs) by Western blot, and its localization by immunofluorescence assays. The antigenicity of the PvRON1 protein was assessed using human sera from individuals previously exposed to P. vivax malaria by ELISA.ResultsIn the P. vivax VCG-1 strain, RON1 is a 764 amino acid-long protein. In silico analysis has revealed that PvRON1 shares essential characteristics with different antigens involved in invasion, such as the presence of a secretory signal, a GPI-anchor sequence and a putative sushi domain. The PvRON1 protein is expressed in parasite's schizont stage, localized in rhoptry necks and it is associated with DRMs. Recombinant protein recognition by human sera indicates that this antigen can trigger an immune response during a natural infection with P. vivax.ConclusionsThis study shows the identification and characterization of the P. vivax rhoptry neck protein 1 in the VCG-1 strain. Taking into account that PvRON1 shares several important characteristics with other Plasmodium antigens that play a functional role during RBC invasion and, as shown here, it is antigenic, it could be considered as a good vaccine candidate. Further studies aimed at assessing its immunogenicity and protection-inducing ability in the Aotus monkey model are thus recommended.

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Identification and characterization of the Plasmodium falciparum RhopH2 ortholog in Plasmodium vivax

Wang

Cheng

et al. 2012

Parasitol Res

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Plasmodium vivax is one of the most important human malaria species that is geographically widely endemic and potentially affects a larger number of people than its more notorious cousin, Plasmodium falciparum. During invasion of red blood cells, the parasite requires the intervention of high molecular weight complex rhoptry proteins (RhopH) that are also essential for cytoadherence. PfRhopH2, a member of the RhopH multigene family, has been characterized as being crucial during P. falciparum infection. This study describes identifying and characterizing the pfrhoph2 orthologous gene in P. vivax (hereinafter named pvrhoph2). The PvRhopH2 is a 1,369-amino acid polypeptide encoded by PVX_099930 gene, for which orthologous genes have been identified in other Plasmodium species by bioinformatic approaches. Both P. falciparum and P. vivax genes contain nine introns, and there is a high degree of similarity between the deduced amino acid sequences of the two proteins. Moreover, PvRhopH2 contains a signal peptide at its N-terminus and 12 cysteines predominantly in its C-terminal half. PvRhopH2 is localized in one of the apical organelles of the merozoite, the rhoptry, and the localization pattern is similar to that of PfRhopH2 in P. falciparum. The recombinant PvRhopH2 protein is recognized by serum antibodies of patients naturally exposed to P. vivax, suggesting that PvRhopH2 is immunogenic in humans.

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Identifying and characterizing a member of the RhopH1/Clag family in Plasmodium vivax

Cited by 6 publications

References 49 publications

Annotation and characterization of the Plasmodium vivax rhoptry neck protein 4 (Pv RON4)

Annotation and characterization of the Plasmodium vivax rhoptry neck protein 4 (Pv RON4)

Identification, characterization and antigenicity of the Plasmodium vivax rhoptry neck protein 1 (Pv RON1)

Identification and characterization of the Plasmodium falciparum RhopH2 ortholog in Plasmodium vivax

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