FIG 3.

mTOR regulates the posttranslational modification of Mint3. (A) Rapamycin treatment increased the isoelectric point of the Mint3 protein. (B) Treatment with Akt inhibitor VIII but not KT5823 decreased Mint3 acidity. (C and D) Knockdown of mTOR decreased Mint3 acidity, but knockdown of MT1-MMP did not. Knockdown of mTOR or MT1-MMP was confirmed by immunoblot (IB) analysis (C), and the acidity of Mint3 in control (shLacZ), mTOR, or Mint3 knockdown cells was analyzed by 2D electrophoresis, followed by immunoblot analysis (D). In panels A, B, and D, the relative intensity of each Mint3 signal is shown above the spot. For an analysis of the boxed areas, see Fig. S2 in the supplemental material. DMSO, dimethyl sulfoxide.