CHARACTERIZATION OF MEMBRANE-PROTEINS EXPORTED FROM PLASMODIUM-FALCIPARUM INTO THE HOST ERYTHROCYTE

Plasmodium falciparum is an intracellular parasite of the red blood ce ll. During development it exports proteins which are transported to sp ecific locations within the host erythrocyte. We have begun to identif y and characterize exported membrane proteins of P. falciparum in orde r to obtain specific marker molecules for the study of the mechanisms involved in the distribution of parasite-derived proteins within the h ost cell. In this report we describe the characterization of a 35 kDa protein which is recognized by a monoclonal antibody. The protein is t ightly associated with membranes isolated from infected erythrocytes; it is resistant to extraction with alkali and soluble after treatment with detergents. It is located at the membrane of the parasitophorous vacuole and in membrane-bound compartments which appear in the cytopla sm of the infected erythrocyte. The protein co-localizes with the prev iously described exported protein-1 (exp-1). Considering its localizat ion and physical similarities to exp-1, we name the 35 kDa protein the exported protein-2 (exp-2).