Pfsbp 1, a Maurer's cleft Plasmodium falciparum protein, is associated with the erythrocyte skeleton

Antibodies from hyperimmune monkey sera, selected by absorption to Plasmodi um falciparum-infected erythrocytes, and elution at acidic pH, allowed us t o characterize a novel parasite protein, Pfsbp1 (P. falciparum skeleton bin ding protein 1). Pfsbp1 is an integral membrane protein of parasite-induced membranous structures associated with the erythrocyte plasma membrane and referred to as Maurer's clefts. The carboxy-terminal domain of Pfsbp1, expo sed within the cytoplasm of the host cell, interacts with a 35 kDa erythroc yte skeletal protein and might participate in the binding of the Maurer's c lefts to the erythrocyte submembrane skeleton. Antibodies to the carboxy- a nd amino-terminal domains of Pfsbp1 labelled similar vesicular structures i n the cytoplasm of Plasmodium chabaudi and Plasmodium berghei-infected muri ne erythrocytes, suggesting that the protein is conserved among malaria spe cies, consistent with an important role of Maurer's cleft-like structures i n the intraerythrocytic development of malaria parasites. (C) 2000 Elsevier Science B.V. All rights reserved.