Isolation and Characterization of an Isoprenoid Transporter Protein in Manduca sexta

Abstract

Metabolic regulation and transport is a fundamental process in all eukaryotic organisms. Metabolites synthesized throughout the cell must be used in various locations to ensure proper cell function. Isoprenoids are metabolite molecules implicated in cell growth, energy production, and act as precursor to steroids, cholesterol, and other derived compounds in living organisms. Within the isoprenoid pathway, isopentenyl pyrophosphate (IPP) was found to be transported by a specific membrane protein molecule in plants (Bick and Lange, 2003). To date, inhibition of this pathway is used in mammalian drug therapy where isoprenoid utilizing enzymes are the candidates of inhibition accomplished by a class of drugs called stains, though many fundamental properties of this pathway await elucidation. The identification and characterization of an IPP transport protein in Manduca sexta would provide a model system for the study of IPP transport in animals as well as to allow characterization of mitochondrial metabolically derived compounds, which have not been possible to study. By isolating mitochondria from M. sexta, this study aims to purify the unknown transport protein for detailed characterization of isoprenoid pathway. These results may allow inhibition and manipulation of the isoprenoid pathway in insects possibly allowing the discovery of new insecticides.