Functional studies of ring exported protein 1 (REX1) in Plasmodium falciparum

Abstract

Malaria remains a fatal disease in some regions, mainly due to cytoadherence of Plasmodium falciparum infected erythrocytes. The P.falciparum Ring Exported Protein 1(REX1) is a resident protein of the Maurer’s clefts, an important intermediary compartment in the trafficking of proteins within the infected cell. REX1 is essential for the architecture of Maurer’s clefts and thus responsible for transport of virulence complex proteins to the erythrocyte surface, causing cytoadherence. This study aimed to determine the region of REX1 responsible for the Maurer’s cleft unstacked phenotype, by constructing three vectors containing truncated REX1 inserts: REX1 no repeats (REX1NR); REX1 repeats (REX1R); REX1 no repeats-C terminal (REX1C). Transfection of these vectors into D10 parasites and subsequent immunofluorescence assays would show effects of the different regions on cleft architecture. Expression of codon-optimised REX1 in Escherichia coli (E.coli) was also performed. While further work is needed for REX1NR, REX1R and REX1C inserts were successfully constructed. Due to time constraints, it was not possible to determine transfection success and conduct immunofluorescence assays. The expression of codon-optimised REX1 in E.coli was achieved, thus providing ample REX1 for future work, particularly structural analysis, which would aid in designing drugs to target the essential regions of REX1.