Characterization of ABC transporters in parasitic nematodes

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ABC transporters have been found in all living organisms and form one of the largest characterized protein families. Organisms that live in diverse environments and that must adapt to various external conditions have a large repertoire of ABC transporters (e.g., Caenorhabditis elegans chromosomes encode 60 ABC transporters) while organisms that occupy a more restricted growth niche have considerably less (e.g., Trypanosoma brucei chromosomes encode 21 ABC transporters). ABC transporters are integral to many cellular processes, yet little is known of these proteins in parasitic nematodes. In farm animals and humans, nematodes cause disease, death and economic loss. Essential to their survival are transport mechanisms, which include ABC transporters. All anthelmintics currently used to treat nematodes target transporters. Some ABC transporter gene sequences have been identified in parasitic nematodes however, functional studies do not exist. The long-term goal of the research is to understand ABC transporter mediated drug resistance in nematodes. Before this can be accomplished, the basic knowledge of ABC transporters in parasitic nematodes must be expanded. To do this Brugia malayi, a nematode that resides in the lymphatic system of humans, will be used as the model organism. The specific goals of the research are to (1) use bioinformatic and genomic analyses to identify and classify the Brugia ABC transporter superfamily; (2) create a spatial proteome of Brugia transporters by transfection of C. elegans with parasite genes; (3) determine the expression patterns in all sexual and life cycle stages using quantitative RT-PCR; and (4) determine the substrate specificity and transport kinetics of Brugia transporters using site-directed mutagenesis and binding assays. The research has implications for expanding the basic knowledge of ABC transporters in parasitic nematodes and providing insight into their cellular functions. As many ABC transporters are targets for anthelmintics, this research will suggest new or alternative control strategies and also expand the existing knowledge of the mechanism of resistance to anthelmintics.