Our objective is to investigate the underlying mechanism in the development and differentiation of malaria parasites, Plasmodium falciparum. The blood-stage parasites of P. falciparum propagate through sexual division (merozoites) and sexual differentiation, which upon intake by mosquitoes will fertilize and preserve its complex life cycle. We have first looked into the function of heat shock proteins (hsps) in parasite development. Hsps are a family of proteins expressed either under stress conditions or constitutively and are well defined among higher eukaryotes. Recent studies of infectious diseases have suggested hsps may play an important role in pathogen development and survival in host. We have identified the genes of two major hsps, hsp60 and hsp90, by screening the genomic DNA and cDNA libraries. Both genes appear to be single-copy genes in the genome. Hsp60 gene is located on chromosome 10. Analysis of their transcripts indicate that the expression of hsp90 is approaching the level of another major hsp, hsp70, which is much higher than that of hsp60. And the expression of hsp90 differs in asexual and sexual stages of parasites, while that of hsp60 remains constant in both stages. We'll next study the signal transduction system in parasites and its role in the development and differentiation.
