P14PFKa in Insulin Release - NRSA for Mary Osisami

DESCRIPTION (provided by applicant): The primary goal of my research is to understand the role of PI4P5Ka in insulin release from pancreatic beta- cells and ultimately to determine if inhibition of PI5P5Kalpha might be beneficial in the treatment of Type II diabetes. PI4P5Ka is an enzyme that generates the signaling lipid PIP2, which has been implicated in the regulation of exocytosis. In mast cells, the loss of PI4P5Kalpha leads to an increased release of immune mediators. My preliminary data suggest that it will play an analogous role in pancreatic beta-cells. The specific aims of this proposal are as follows: to determine the role of PI4P5Kaalpha in glucose-simulated insulin release (GSIR) using glucose and insulin tolerances tests, 2) to use thin layer chromatography, immunohistochemistry of islet cells, and insulin normalization to DNA to determine if the levels of PIP2, insulin, and beta-cell mass are altered in PI5P5Kalpha -/- cells, 3) to determine whether the decreased levels of PIP2 alter the actin cytoskeleton organization, its relationship to SNARE proteins, or insulin secretory vesicle subcellular localization, and 4) to determine if mice predisposed to type II diabetes exhibit improved glucohomeostasis in the absence of PI4P5Kalpha.