The C-terminal domain of the Plasmodium falciparum acyl-CoA synthetases PfACS1 and PfACS3 functions as ligand for ankyrin.

Infection of erythrocytes by the malaria parasite Plasmodium falciparum results in the export of several parasite proteins into the erythrocyte cytoplasm establishing novel interactions between host and parasite proteins, particularly at the membrane skeleton that modifies both the structural and functional properties of the red cell. We present evidences that two members of the P. falciparum acyl-CoA synthetase (PfACS) family, responsible for the activation of long-chain fatty acids by thio-esterification with CoA, are transported in vesicle-like structures toward the host erythrocyte cytoplasm where they interact with the cytoskeletal protein ankyrin. Carboxyl-terminal domain (CTD) overlay studies indicated that PfACS1 and PfACS3 bind to the 78-kDa fragment of ankyrin corresponding with its spectrin-binding domain. Co-immunoprecipitation of ankyrin and PfACS1/3 indicates that at least a fraction of these proteins are physically associated in the infected erythrocytes and provide evidence for a novel specific interaction which suggest that such a binding may bring these enzymes closer to the host erythrocyte membrane where exogenous fatty acids are available.