Rac1 signalling towards GLUT4/glucose uptake in skeletal muscle

Small Rho family GTPases are important regulators of cellular traffic. Emerging evidence now implicates Rac1 and Rac-dependent actin reorganisation in insulin-induced recruitment of glucose transporter-4 (GLUT4) to the cell surface of muscle cells and mature skeletal muscle. This review summarises the current thinking on the regulation of Rac1 by insulin, the role of Rac-dependent cortical actin remodelling in GLUT4 traffic, and the impact of Rac1 towards insulin resistance in skeletal muscle.

Research highlights
► Insulin activates Rac1 in muscle cells and mature skeletal muscle.
► Activation of Rac1 is required for insulin-mediated GLUT4 traffic to the cell surface.
► Rac-dependent actin reorganisation facilitates insulin-induced GLUT4 translocation.
► Rac activation becomes impaired during conditions of insulin resistance.