This family includes 3-phosphoinositide-dependent protein kinase 1 (PDK1 or PDPK1) and related kinases from yeast: Pkh1 and Pkh2 from S. cerevisiae, which function similarly to PDK1 [], and Ksg1 []and Ppk21 from S. pombe [].PDK1 is the kinase responsible for the phosphorylation of PKB/Akt on the activation loop, at threonine 308, which is essential for Akt activation [, ]. Beyond Akt, PDK1 is responsible for the phosphorylation of many other AGC kinases including serum/glucocorticoid regulated kinase (SGK) []and the members of protein kinase C (PKC) family []. PDK1 is implicated in signaling pathways frequently altered in cancer, such as PI3K/Akt, Ras/MAPK and Myc []. It is a key regulator of cell migration and tumor invasion []. PDK1 binds to the insulin receptor, followed by tyrosine phosphorylation of PDK1 by the insulin receptor, which is necessary for insulin metabolic signaling []. Deficiency of PDK1 in liver results in glucose intolerance [].
