Fig. 3.

Effects of proteasome and lysosome inhibitors on EGFR content of MEFs expressing ARD1 proteins. (A) After induction with Mfp without (C) or with proteasome (P) or lysosome (L) protease inhibitors, the indicated ARD1 KO MEFs were analyzed by Western blotting with antibodies against EGFR. (B) Densitometric values for EGFR in P and L samples expressed relative to that of α-tubulin in the same sample were normalized to the value for the same cells (C) without inhibitors equal to 100%. Data are from three experiments. Only after Mfp induction of ARD1–GDP and ARD1–GTP mutants with proteasome inhibitors were ARD1 levels significantly (p < 0.05) different from (higher than) those of the same cells without inhibitors. (C) Immunoblot from a representative experiment with antibodies against ubiquitin (Ub) and α-tubulin.