NSF Award
0344541
Intracellular vacuoles play important roles in cell function. The PI's research group is using a combination of molecular genetic and imaging techniques to characterize the dynamics and interactions of the contractile vacuole complex, an osmoregulatory organelle, and early steps in the endo-lysosomal pathway in the model microorganism. Dictyostelium discoideum. Prior NSF support enabled the PI to create a novel probe that allows proton pump trafficking to be monitored in living cells to explore the function of the V-ATPase. In this new project the PI will use the proton pump trafficking probe and other probes that monitor the evolution of pH along the endo-lysosomal pathway to characterize the trafficking of the V-ATPase and other key proteins in relation to endosomal acidification, neutralization, fusion, and exocytosis. Other studies will test the hypothesis that the endocytic pathway treats food particles differently from non-digestible substances. In related work, the PI will utilize GFP chimeras of ER-resident proteins to examine the proposition that endoplasmic reticulum is incorporated into a forming phagosome, and to investigate whether such incorporation depends on the nature of the phagocytosed particle. Finally, genetic and biochemical screens will be used to identify the cell surface receptors that allow Dictyostelium cells to recognize their prey, and the possible relationship of these receptors to macrophage receptors that function in innate immunity will be explored. This project will be coordinated with an ongoing outreach program, the Oklahoma Science Project, which brings rural high school teachers to the Oklahoma Medical Research Foundation for two summer months to participate in research.
