Small GTP-binding proteins in Plasmodium falciparum.
During its erythrocytic life cycle Plasmodium falciparum exchanges compounds with host cells through phagocytosis and exocytosis. In eucaryotic cells, small GTP-binding proteins of the Ras superfamily appear to be involved in different steps of membrane trafficking and in intracellular signals. In this paper, we investigate the Rab4, Rab6 and Ras-related proteins in P falciparum infected red cells. We report that P falciparum Rab and Ras-related proteins could be distinguished from their counterparts by iso-electrofocusing and immunoblotting. The localization of P falciparum Rab 4 and Rab 6 was studied by immunogold electron microscopy on ultrathin frozen sections of infected red blood cells. Rab4 parasite-related protein was found associated with the membranes of early endosome-like structures near the parasite plasma membrane. Rab6-related protein was associated with the Golgi/trans Golgi network, as already suggested by immunofluorescence microscopy studies and Ras-related protein was cytoplasmic and plasma membrane-associated. These results are in accordance with their mammalian counterparts and support the implication of Rab-related proteins in vesicular trafficking in Plasmodium.
Jambou
R
R
IMEA/INSERM U13, CHU Bichat-Claude Bernard, Paris, France.
Zahraoui
A
A
Olofsson
B
B
Tavitian
A
A
Jaureguiberry
G
G
D000818:Animals; D001345:Autoradiography; D015153:Blotting, Western; D019204:GTP-Binding Proteins / Q000032:analysis; D007150:Immunohistochemistry; D010963:Plasmodium falciparum / Q000378:metabolism* / Q000648:ultrastructure; D018631:ras Proteins / Q000032:analysis*
D019204:GTP-Binding Proteins; D018631:ras Proteins