Figure 1.

GSK-3 phosphorylation increases specifically in myotubes during differentiation of C2.7 myoblasts. Proliferative (Prolif) or 3-d differentiated (Diff) C2.7 myoblasts were harvested. The two populations of cells after 3-d differentiation were separated into undifferentiated reserve cells (Res) and myotubes (MT), harvested and analyzed by Western blot for total content of GSK-3α and β (panGSK-3), and for GSK-3 phosphorylation status (pGSK-3). In parallel, extracts were blotted with an antibody antiphospho-Akt directed against serine 473 (pAkt) and for total Akt protein (pan-Akt).