Rhoptry neck protein RON2 forms a complex with microneme protein AMA1 in Plasmodium falciparum
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- 作者：Jun Cao ; Osamu Kaneko ; Amporn Thongkukiatkul ; Mayumi Tachibana ; Hitoshi Otsuki ; Qi Gao ; Takafumi Tsuboi ; Motomi Torii
- 关键词：AMA1 ; Erythrocyte invasion ; Merozoite ; Plasmodium falciparum ; Rhoptry
- 刊名：Parasitology International
- 出版年：2009
- 出版时间：March 2009
- 年：2009
- 卷：58
- 期：1
- 页码：29-35
- 全文大小：1247 K
文摘
Erythrocyte invasion is an essential step in the establishment of host infection by malaria parasites, and is a major target of intervention strategies that attempt to control the disease. Recent proteome analysis of the closely-related apicomplexan parasite, Toxoplasma gondii, revealed a panel of novel proteins (RONs) located at the neck portion of the rhoptries. Three of these proteins, RON2, RON4, and RON5 have been shown to form a complex with the microneme protein Apical Membrane Protein 1 (AMA1). This complex, termed the Moving Junction complex, localizes at the interface of the parasite and the host cell during the invasion process. Here we characterized a RON2 ortholog in Plasmodium falciparum. PfRON2 transcription peaked at the mature schizont stage and was expressed at the neck portion of the rhoptry in the merozoite. Co-immunoprecipitation of PfRON2, PfRON4 and PfAMA1 indicated that the complex formation is conserved between T. gondii and P. falciparum, suggesting that co-operative function of the rhoptry and microneme proteins is a common mechanism in apicomplexan parasites during host cell invasion. PfRON2 possesses a region displaying homology with the rhoptry body protein PfRhopH1/Clag, a component of the RhopH complex. However, here we present co-immunoprecipitation studies which suggest that PfRON2 is not a component of the RhopH complex and has an independent role. Nucleotide polymorphism analysis suggested that PfRON2 was under diversifying selective pressure. This evidence suggests that RON2 appears to have a fundamental role in host cell invasion by apicomplexan parasites, and is a potential target for malaria intervention strategies.