Erythrocyte membrane protein 1 VAR2CSA (VAR2CSA)

VAR2CSA is a large (~310–350 kDa) transmembrane protein of the *Plasmodium falciparum* erythrocyte membrane protein 1 (PfEMP1) family, specifically expressed on the surface of infected erythrocytes during pregnancy-associated malaria. Its extracellular region consists of six Duffy-binding-like (DBL) domains and multiple interdomain regions, organized in a V-shaped or compact, pore-like multidomain structure that specifically binds chondroitin sulfate A (CSA) chains on placental syncytiotrophoblasts. This interaction enables infected erythrocytes to sequester in the placenta, leading to complications such as maternal anemia and low birth weight. VAR2CSA is considered the principal molecular target for vaccines seeking to prevent placental malaria, and the focus of several vaccine candidates that elicit antibodies to block its adhesion function. Structural studies reveal distinct CSA-binding channels formed by multiple domains, explaining the necessity of the full protein architecture for high-affinity, specific adhesion. No direct drugs exist, but vaccine development is ongoing; challenges include antigenic diversity and immune evasion.

Other names

Plasmodium falciparum erythrocyte membrane protein 1 VAR2CSAPfEMP1 VAR2CSAvar2csa

Vaccine candidates use VAR2CSA fragments to elicit antibodies that block adhesion of infected erythrocytes to placental CSA, thereby preventing sequestration and pathology.