A Plasmodium chabaudi chabaudi high molecular mass glycoprotein translocated to the host cell membrane by a non-classical secretory pathway

• Published in: European journal of cell biology Vol. 78; no. 3; pp. 186 - 193
• Main Authors: Cruz Moura, Ivan, Pudles, Julio
• Format: Journal Article
• Language: English
• Published: Germany Elsevier GmbH 01.03.1999
• Subjects: Animals; Biological Transport; Brefeldin A - pharmacology; Carbonates; Cell Membrane - metabolism; Erythrocytes - metabolism; Erythrocytes - parasitology; Female; glycoproteins; Glycoproteins - metabolism; Glycoproteins - secretion; Glycosylation; malaria; Mice; Mice, Inbred BALB C; Molecular Weight; Peptides - metabolism; Plasmodium chabaudi - metabolism; Plasmodium chabaudi chabaudi; Protein Synthesis Inhibitors - pharmacology; protein transport; Protozoan Proteins - metabolism; Protozoan Proteins - secretion; Temperature; protein transport; PBS; IRBCs; IFA; PVM; IRBCM; glycoproteins; i.p; malaria; PPM; Plasmodium chabaudi chabaudi; ER; FITC; BFA
• ISSN: 0171-9335; 1618-1298
• DOI: 10.1016/S0171-9335(99)80097-1

We have purified and characterized a novel high molecular mass glycoprotein of P. chabaudi chabaudi (Pc550gp) that is transported to the erythrocyte membrane during the intraerythrocytic cycle. Immuno fluorescence assays with polyclonal monospecific antibodies against Pc550gp show that the protein to be localized in the periphery of young trophozoite stages i.e, on the plasma membrane or parasitophorous vacuole membrane. However, in late trophozoites and schizonts the antigen is distributed in both parasite and host cell membranes. These results were confmned by inununoblotting of isolated parasites and infected host cell membranes at different stages of parasite development. Moreover, alkali extraction of purified infected erythrocyte membranes at mature stages of parasite development does not solubilize Pc550gp, suggesting that it is an integral membrane protein. In addition proteinase K digestion of intact infected host cells induced the disappearance of Pc550gp, further indicating its transmembrane nature and that it presents extracellular domains susceptible to proteolysis. Brefeldin A or low temperature (15 °C treatment did not affect the translocation of Pc550gp from the parasite compartments to the erythrocyte membrane, indicating that the secretion of Pc550gp does not follow the classical transport pathway described in most eukaryotic cells.