Analysis of mammalian cell growth factor receptor dynamics

We have proposed a mathematical model for the events following binding of EGF to cell surface receptors with the aim of elucidating possible mechanisms associated with a lack of responsiveness to EGF mitogenic stimulation. Comparison of our model calculations with the experiments of Schaudies et al. suggests at least two possible mechanisms: an increase in the rate of receptor synthesis, or an increase in the fraction of internalized receptors that are recycled to the cell surface. Discrimination between these alternatives requires experimental measurement of cell receptor quantities, such as the number of surface complexes or the amount of degraded receptor. At the present time, we speculate that an increase in the fraction of receptors recycled seems to be the more likely explanation.