Recycling of epidermal growth factor in A431 cells.
The fate of epidermal growth factor (EGF) after internalization by A431 cells was studied. First, cells containing 125I-EGF-receptor complexes in endosomes were obtained. Subsequent incubation of the cells at 37 degrees C resulted in the recycling of 125I-EGF from endosomes to the cell surface in the receptor-bound state and the gradual release of recycled ligand into the medium. The excess of unlabeled EGF blocked both rebinding and re-internalization of recycled 125I-EGF to produce enhanced accumulation of ligand in the medium. The rate of recycling was shown to be much higher than that of EGF degradation.
D000818:Animals; D002294:Carcinoma, Squamous Cell / Q000378:metabolism*; D002458:Cell Fractionation; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D002499:Centrifugation, Density Gradient; D003593:Cytoplasm / Q000378:metabolism; D004705:Endocytosis; D004815:Epidermal Growth Factor / Q000378:metabolism*; D066246:ErbB Receptors / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D051379:Mice
D004815:Epidermal Growth Factor; D066246:ErbB Receptors