Figure 9.

Cortical actin remodeling controls a distal GLUT4-trafficking event. Insulin initiates the translocation of GLUT4 vesicles along microtubules from an intracellular storage compartment to the PM. We propose Akt functions at multiple steps in the process, to regulate the transport (1), attachment (2), and fusion (3) of GLUT4 vesicles. Inhibiting Akt function upstream impairs vesicle attachment and fusion at the PM. In contrast, actin polymerization specifically regulates this process downstream of vesicle attachment, at a step that may directly drive the incorporation of GLUT4 into the PM.