[The recycling of EGF-receptor complexes in A431 cells]

As was demonstrated elsewhere (L. V. Teslenko et al., 1987), the epidermal growth factor (EGF) can recycle after internalization by A431 cells in membrane-bound state. In the present study, direct evidence on recycling of EGF-receptor complexes is presented using a covalently crosslinking reagent. The recycling was shown to occur via peripheral endosomes as well as through para-Golgi endosomes. It was found that among EGF degradation inhibitors tested only primaquine (300 microM) was able to decrease significantly the rate of recycling. The lowering of the temperature to 17 degrees C led to blocking the EGF degradation as well as to inhibiting the recycling. The data obtained suggested that the recycling of EGF-receptor complexes is relatively independent of their degradation.