PKC inhibition blocks PDGF-induced macropinocytosis and mTORC1 activation independent of TSC function. (A) Macropinosome formation in TSC2-WT (left) and TSC2-knockout (KO) (right) MEFs stimulated by PDGF in the presence of FDx with (bottom) or without (top) calphostin C (cal C). FDx-labeled macropinosomes are indicated by red overlay. Bar, 10 µm. (B) Macropinocytosis and activation of mTORC1 in TSC2-WT and TSC2-KO MEFs was increased by PDGF and inhibited by calphostin C. Bars indicate the means ± SEM of three trials. *, P < 0.05.