Fig. 1

Both physical and chemical stress conditions induce degradation of EGFR. HeLa cells were cultured in DMEM plus 10 % FBS to 90 % confluence and serum-starved for 12 h. For puromycin (5 μg/ml), anisomycin (60 μM) or EGF (100 ng/ml) treatment, the stock solution of the chemical was added to the medium for indicated time. For 0.7 M NaCl treatment, the cells were cultured in serum-free DMEM medium plus 0.7 M NaCl for indicated time. For UV treatment, the cells were irradiated under a UV light (about 8 J/cm²) for 2 min, then cultured in serum-free medium for indicated time. The cells were lysed and EGFR was immunoprecipitated with anti-EGFR (Mab528) and detected by immunoblotting with anti-EGFR(1005). The amount of lysates used for Immunoprecipitation was controlled by immunoblotting of β-actin (bottom panels) in whole cell lysates with anti-β-actin