Genetic Polymorphism of Plasmodium vivax msp1p, a Paralog of Merozoite Surface Protein 1, from Worldwide Isolates

Abstract

Plasmodium vivax msp1p, a paralog of the candidate vaccine antigen P vivax merozoite surface protein I, possesses a signal peptide at its N-terminus and two epidermal growth factor like domains at its C-terminus with a glycosylphosphatidylinositol attachment site. The msp1p gene locus may have originated by a duplication of the msp1 gene locus in a common ancestor of the analyzed Plasmodium species and lost from P yoelii, P berghei, and P falciparum during their evolutionary history. Full-length sequences of the msp1 p gene were generally highly conserved; they had a few amino acid substitutions, one highly polymorphic E/Q-rich region, and a single-to-triple hepta-peptide repeat motif. Twenty-one distinguishable allelic types (A1-A21) of the E/Q-rich region were identified from worldwide isolates. Among them, four types were detected in isolates from South Korea. The length polymorphism of the E/Q-rich region might be useful as a genetic marker for population structure studies in malaria-endemic areas.