Figure 4

Western blots showing the effect of DSLET or EGF on tyrosine phosphorylation of the δ-OR or the EGFR. HEK-δ-OR cells were serum-starved overnight prior to exposure to EGF (0.1 – 100 ng/ml for 5 minutes) or DSLET (10 nM-10 μM for 5 minutes). After agonist exposure, cell lysates were prepared and the δ-OR or the EGFR was immunoprecipitated as described in the methods section using the appropriate antibodies. Tyrosine phosphorylation of these receptors was determined by SDS PAGE, followed by immunoblotting of proteins onto nitrocellulose. Immunopositive bands correspond to the tyrosine-phosphorylated forms of the δ-OR (upper panel) or the EGFR (lower panel). The immunoblots are representative of an experiment that was repeated three times.