FIGURE 2.

Acute Rac-1 activation via rapamycin-triggered heterodimerization induces GLUT4 translocation in muscle cells. YF, YF-CA-Rac, or YF-Tiam1 was co-transfected with/without Lyn-FRB in myoblasts. Cells were treated with/without rapamycin for 10 min followed by rounded-up myoblast assay and detecting the redistribution of the YFP signal (A), permeabilization and staining with rhodamine-phalloidin to measure changes in F-actin (B), and measurement of surface GLUT4myc (C and D). Changes were compared with those in YFP-expressing myoblasts stimulated with/without insulin and quantified relative to the YFP basal signal (mean ± S.E. (error bars); *, p < 0.05). Representative images of three independent experiments are shown. Bar, 10 μm.