The transformation of Schistosoma mansoni cercariae into schistosomula occurs over 3h and is associated with marked changes in the parasite's morphology and biochemical processes. At the beginning of this period, proteins of Mr 58,000 and 60,000 (transformation associated proteins) are most prominently synthesized, but at the end of 3h all synthesis of these proteins ceases abruptly. Because of their rapid induction and sharply defined end of synthesis, these proteins appear to be very strictly regulated during transformation. The general objective of this project is to elucidate some of the mechanisms of gene regulation that occur during transformation. As a first step in this direction, the aims of the current proposal are: 1) to characterize the chemical properties, the function and regulatory factors for induction of the Mr58,000-60,000 proteins and 2) to sequence the coding and regulatory regions of the corresponding gene or genes. Chemical characteristics such as glycosylation, and phosphorylation and functional characteristics such as protease and ATP binding activities will help relate the transformation associated proteins to other proteins with similar characteristics. Transcriptional regulation and the participation of protein kinase C and G proteins in the induction of the Mr58,000-60,000 proteins will be assessed by appropriate inhibitors. A combination of gel filtration, chromatofocusing and/or hydrophobicity chromatography will be used to purify proteins from cercariae. The purified proteins will then be used to obtain a partial protein sequence or to induce polyclonal antibodies. Oligonucleotide probes derived from the partial protein sequence or specific polyclonal antibodies will be used to screen expression cDNA and genomic libraries for clones corresponding to the Mr58-60,000 proteins. The clones themselves will be for comparison with the coding and regulatory regions of known of known genes. They will also be used to study the expression of these proteins during development and to aid in localizing the protein by in situ hybridization. The putative promoter region will be used in footprinting experiments and affinity chromatography to identify transacting transcriptional factors. Finally, the genomic DNA will be introduced into established vertebrate cell lines to determine if the regulatory signals for these genes are shared.
| Li, Z; King, C L; Ogundipe, J O et al. (1995) Preferential recognition by human IgE and IgG4 of a species-specific Schistosoma haematobium serine protease inhibitor. J Infect Dis 171:416-22 |
| Blanton, R E; Licate, L S; Aman, R A (1994) Characterization of a native and recombinant Schistosoma haematobium serine protease inhibitor gene product. Mol Biochem Parasitol 63:1-11 |
| Blanton, R E; Licate, L S (1992) Developmental regulation of protein synthesis in schistosomes. Mol Biochem Parasitol 51:201-8 |
| Armitage, K B; Blanton, R E (1991) Paroxysmal fluctuations in observed parasitemia in Plasmodium falciparum malaria. Am J Med 90:530-1 |
