Roles of Akt and SGK1 in the Regulation of Renal Tubular Transport

Figure 4

SGK1-mediated signaling pathway. Aldosterone stimulates SGK1 via mineralocorticoid receptor (MR), while insulin stimulates SGK1 via IRS/PI3K pathway. SGK1 is phosphorylated twofold by PDK1 and PDK2. Activated SGK1 exerts stimulatory effects on sodium transport through ENaC, NCC, and NHE3. Also, SGK1 regulates potassium secretion through ROMK. SGK1: serum- and glucocorticoid-inducible kinase 1, IRS: insulin receptor substrate, PI3K: phosphatidylinositol 3-kinase, PDK1: phosphoinositide-dependent protein kinase 1, WNK1: with-no-lysine kinase 1, ENaC: epithelial Na⁺ channel, ROMK: renal outer medullary potassium channel, and NHE3: sodium-proton exchanger 3.