Structural requirements for protein transport across the vacuolar membrane of Plasmodium falciparum

• Applicant: Professor Dr. Klaus Lingelbach (†)
• Subject Area: Parasitology and Biology of Tropical Infectious Disease Pathogens
• Term: from 2002 to 2005
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5374421

Plasmodium falciparum is an obligatory intracellular parasite that induces morphological and physiological alterations of its host erythrocyte. These modifications are mediated by proteins which are synthesised and secreted by the parasite. In order to reach their final destinations the proteins have to be transported across the membrane of a vacuole which surrounds the parasite and which forms a barrier to the erythrocyte cytosol. The protein signals and the mechanisms that allow transport of specific parasite proteins across the vacuolar membrane are largely unknown. Conflicting experimental data exist whether specific protein signals are required to mediate this process. We want to resolve this discrepancy by constructing genes encoding chimeric proteins. The genes will be expressed in transfected parasites and the localisation of the gene products will be analysed by fractionation of infected erythrocytes and by confocal laserscan microscopy. In a complementary approach, translocation of proteins across the vacuolar membrane will be analysed after selective permeabilization of the erythrocyte plasma membrane. This experimental system will allow to manipulate the biochemical composition of the vacuole and of the erythrocyte cytosol. Thus, synergistic effects of protein structure and biochemical parameters can be analysed.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1131: Life Inside Cells