Analysis of PfEMP1—var Gene Sequences in Different Plasmodium falciparum Malarial Parasites

Abstract

Plasmodium falciparum synthesizes P. falciparum erythrocyte membrane protein-1 (PfEMP-1), a product of the multicopy var gene family, which localizes on the surface of infected erythrocytes. This protein plays an important role in cytoadherence and immune evasion. Comparative analysis of the molecular sequences of the DBLα domain of the var gene from different isolates of the parasite reveals variations in the number of cysteines and presence of small conserved motifs like DGEA, RGD, GAG-binding motifs. Phylogenetic analysis while highlighting the extensive diversity leads to clustered them in separate clades far apart from each other. Discriminant factor analysis of physicochemical properties of amino acid sequences revealed that the aliphatic index, isoelectric point, and instability index have more effect in deciding the variance of different isolates sequences. The origin of diverse repertoire of the DBLα domain in the parasites highlights the complexity of host-parasite relationship in the context of parasite survival.

Genetic diversity of Plasmodium falciparum erythrocyte membrane protein 1 in field isolates from central Myanmar

“…The number of cysteine residues determines the classification of the DBLα domain and the severity of the disease [ 6 , 30 ]. Polymorphism within the hypervariable region induced via gene recombination and/or duplication results in length and sequence variability among parasites between and within hosts in malaria-endemic areas [ 31 ]. The DBLα domain has an average of 4 cysteine residues, and the number can vary from 2 to 9.…”

Comparative study of Plasmodium falciparum erythrocyte membrane protein 1-DBLα domain variants with respect to antigenic variations and docking interaction analysis with glycosaminoglycans

“…This diversity has been reported in field isolates of different geographical regions. [23][24][25][26][27][28] The great antigenic diversity and unique regulation of switching between different antigenic variants of PfEMP1 enables the parasite to evade the immune system and to maintain severe and chronic infection. 7 Several reports have stressed this molecule as a vaccine candidate 29 and an anti-rosetting agent.…”