FIGURE 7.

Depletion of subunits from ESCRT-0, -I, -II, or -III attenuates CXCR4-promoted Akt signaling. A–D, depletion of individual subunits from each of the ESCRT complexes attenuates CXCR4-promoted Akt activation. HeLa cells treated with siRNA directed against STAM1 (ESCRT-0), UBAP1 (ESCRT-I), Vps22 (ESCRT-II), CHMP4C (ESCRT-III), or luciferase (Ctrl) were serum-starved for 3 h followed by treatment with vehicle (minus symbol) or CXCL12 (plus symbol) for 5 min. Equal amounts of whole cell lysates were immunoblotted for the indicated proteins and their phosphorylation status. Samples are from the experiments described in Fig. 4. Representative blots from four independent experiments are shown. V, vehicle; S, CXCL12; E, EGF; and I, insulin.