AKT1 and Hyperglycemia: 3-Phosphoinositide-dependent protein kinase-1 (PDK1) is a 63-kDa serine/threonine kinase that functions downstream of PI3K but upstream of Akt and serves as a major regulatory point in Akt signaling.11 Mice lacking PDK1 die in utero, and mice that lack PDK1 specifically in the pancreatic β cells develop progressive hyperglycemia as a result of the loss of islet mass.12, 13