A study of candidate parasitophorous vacuole membrane proteins of the malarial parasite Plasmodium falciparum

• Main Author: Johnson, Delia Lynn
• Published: University of Edinburgh 1993
• Subjects: 616.079
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.653037

More than 40% of the world's population still live under the threat of malaria. Present drug and vaccine strategies are failing to eradicate or even control the disease. A greater understanding of the molecular biology of the intracellular parasite is necessary in order to develop better chemotherapy and vaccine strategies. One aspect of the parasite's biology which may yield new drug targets, are novel trafficking pathways which are established when it invades a red blood cell. In order to study the mechanisms involved in such pathways, specific proteins found in defined locations in the host cell must be studied. One group of proteins that may prove useful in such studies are exported integral membrane proteins because they may act as markers for the polarity of certain membranes. Previous work in our laboratory has focused on the integral membrane protein exp-1. In order to test the validity of a model proposed for its transport to the cytoplasm other exported, parasite encoded, integral membrane proteins need to be identified. This thesis has focused on other parasite encoded proteins which appear to be exported by the parasite to the parasitophorous vacuole membrane (PVM). The initial approach adopted was to study a protein recognised by a specific monoclonal antibody, 7.7. Using a double labelling indirect immunofluorescence technique this antigen, termed exp-2, was shown to be co-localised with exp-1 in the parasitophorous vacuole membrane (PVM) and in vesicle-like structures in the erythrocyte cytoplasm. In the course of attempting to isolate the exp-2 gene another antigen, exp-3, was isolated. Further characterization of exp-3 indicated that it was a member of a two gene family. Both genes were isolated and found to be located on chromosome 13. Sequence analysis of the two genes showed that the genes appear to be highly conserved at the amino terminus and diverge in a repeat region towards their C-terminus.