Effect of cycloheximide on epidermal growth factor receptor trafficking and signaling

► Cycloheximide induces internalization and redistribution of EGF receptor. ► Cycloheximide affects EGF-induced activation of EGF receptor and ERK1/2. ► MAPK p38 is involved in the cycloheximide-induced internalization of EGF receptor. Cycloheximide is the most common protein synthesis inhibitor, and is believed to specifically inhibit the cytoplasmic protein synthesis. Here we demonstrate that cycloheximide induces internalization and redistribution of EGF receptor to early endosomes in HeLa cells independent of receptor tyrosine phosphorylation, but dependent on p38 MAPK activity. Degradation of EGF receptor or its downstream effectors was not observed. EGF-induced activation of ERK1/2 was inhibited upon pre-treatment with cycloheximide, but did not activate JNK. The observed effects of treatment with cycloheximide alone are significant and therefore results involving the use of cycloheximide for inhibition of protein synthesis must be interpreted with caution. EEA1 and EGFRcolocalize by fluorescence microscopy (View interaction).