SRA

Proteomics analysis of midgut epithelial cell brush border membrane vesicles of Trichoplusia ni.Trichoplusia ni is an economically important crop pest; T. ni larvae damage cruciferous plants by devouring leaf and new shoots. Biological controls including insect specific pathogens Baculoviruses and Bacillus thuringiensis (Bt) crystalline toxins are effective environment friendly tools to minimize crop damage by pests. Larval midgut is the site of various vital events including food digestion, interaction with pathogens and toxins, and transport of molecules into insect body. Midgut is lined by midgut cellular layer of epithelial, goblet and regenerative cells. Columnar epithelial cells are most abundant of the midgut cells and they have molecular membrane protrusions called brush border membrane (BBM) on apical side of the cells. BBM provides increased surface area for epithelial cells to transport nutrients and interact with luminal contents including pathogens and toxins. BBM has specific set of proteins and some of them are receptors for pathogen and toxin binding. It is very important to determine the proteome of BBMs to fully understand the biochemical, physiological processes as well as interactions of BBM with Bt toxins and Baculoviruses. Recent improvements in proteomics tools have provided us an opportunity to determine the proteome of T. ni BBM to unprecedented details. This study reports the identification of BBM proteins of T. ni BBM enriched fraction of midgut cell layer using single dimension polyacrylamide gel electrophoresis and multidimensional protein identification technology. This study identified more than 1900 proteins; functional prediction of the proteins likely to be localized in BBM was carried out. Further analysis of individual proteins for the presence of transmembrane domains, GPI anchor or secretory peptide signal and subcellular localization identified more than 250 proteins to be localized in BBM. We found proteins likely to be involved in diverse functional categories. As expected most of the proteins identified in this study were related to digestion, transport of molecules across cell membrane and uncharacterized proteins. We believe this is most detailed proteome of T. ni BBM to date which will help the scientific community to better understand the biochemical, physiological and pathological processes taking place in the T. ni midgut.