Fig. 6.

Schematic overview of the regulation of GLUT4 translocation. Insulin stimulates Akt phosphorylation and activity, whereas muscle contraction activates AMPK by inducing phosphorylation of Thr¹⁷² and by allosteric activation by AMP. Muscle contraction can also activate Akt, but the importance of this signaling pathway for glucose uptake remains unclear. AMPK and Akt are established kinases of the phosphorylation sites on AS160 and TBC1D1 investigated in this study, but other kinases activated by muscle contraction could also be involved. P, phosphorylation; ?, putative protein or mechanism. Solid arrows illustrate established relationships between stimuli, signals, and glucose transport; dashed arrows are used for putative interactions.