Project IV
Functional Protomics of the Golgi complex studied in the Mammary Epithelial cell.
Our goal in this project is to understand the molecular changes that occur within the Golgi complex of a cell as its functional state changes from basal to maximal secretion. The mammary epithelial cell provides an ideal system in which to study this transition. In response to the complex hormonal changes at parturition, the Golgi complex rapidly expands and the synthesis and secretion of the components of milk is initiated. We are using proteomics to identify the molecular changes that occur in the Golgi complex in the two distinctly different functional states. In the first installment, our global analysis revealed a subset of the total protein compliment is up-regulated, a different, smaller subset is down-regulated, while the majority of proteins remain constant. Individual proteins are being selected to overexpress, knock out, and/or mutate and the effect on the regulation of the secretory process in mammary epithelial cells will be tested. This approach will allow us to define the molecular basis for the regulation of secretion.