FIGURE 3.

Podocyte insulin signaling. Podocytes are the first cells to interact with insulin at the nephron and express several proteins of the canonical insulin signaling pathway. However, here the podocyte-specific protein nephrin is known to have a role in the trafficking of glucose transporters (GLUT1 or GLUT4) to podocyte membrane and consequently promote glucose uptake. The trafficking seems to involve Vamp2 and actin remodeling. On the other branch of insulin signaling, an effect in the large-conductance Ca²⁺-activated K⁺ channels (BK_Ca) is also important for maintenance of podocyte integrity and proper glomerular filtration. GRB2, growth factor receptor-bound protein 2; GSV, GLUT storage vesicle; VAMP2, Vesicle-associated membrane protein 2.